Merge pull request #7590 from opensourcerouting/isisd-lfa

isisd: add support for classic LFA

69 files changed, 7844 insertions, 247 deletions

diff --git a/doc/user/isisd.rst b/doc/user/isisd.rst
index 81333a216..f991e3f07 100644
--- a/doc/user/isisd.rst
+++ b/doc/user/isisd.rst
@@ -175,6 +175,35 @@ ISIS Timer
 
    Set minimum interval between consecutive SPF calculations in seconds.
 
+.. _isis-fast-reroute:
+
+ISIS Fast-Reroute
+=================
+
+.. index:: spf prefix-priority [critical | high | medium] WORD
+.. clicmd:: spf prefix-priority [critical | high | medium] WORD
+
+.. index:: spf prefix-priority [critical | high | medium] WORD
+.. clicmd:: no spf prefix-priority [critical | high | medium] [WORD]
+
+   Assign a priority to the prefixes that match the specified access-list.
+
+.. index:: fast-reroute priority-limit [critical | high | medium] [level-1 | level-2]
+.. clicmd:: [no] fast-reroute priority-limit [critical | high | medium] [level-1 | level-2]
+
+   Limit LFA backup computation up to the specified prefix priority.
+
+.. index:: fast-reroute lfa tiebreaker [downstream | lowest-backup-metric | node-protecting] index (1-255) [level-1 | level-2]
+.. clicmd:: [no] fast-reroute lfa tiebreaker [downstream | lowest-backup-metric | node-protecting] index (1-255) [level-1 | level-2]
+
+   Configure a tie-breaker for multiple LFA backups. Lower indexes are processed
+   first.
+
+.. index:: fast-reroute load-sharing disable [level-1 | level-2]
+.. clicmd:: [no] fast-reroute load-sharing disable [level-1 | level-2]
+
+   Disable load sharing across multiple LFA backups.
+
 .. _isis-region:
 
 ISIS region
@@ -356,6 +385,16 @@ ISIS interface
    Enable or disable :rfc:`5303` Three-Way Handshake for P2P adjacencies.
    Three-Way Handshake is enabled by default.
 
+.. index:: isis fast-reroute lfa [level-1 | level-2]
+.. clicmd:: [no] isis fast-reroute lfa [level-1 | level-2]
+
+   Enable per-prefix LFA fast reroute link protection.
+
+.. index:: isis fast-reroute lfa [level-1 | level-2] exclude interface IFNAME
+.. clicmd:: [no] isis fast-reroute lfa [level-1 | level-2] exclude interface IFNAME
+
+   Exclude an interface from the LFA backup nexthop computation.
+
 .. index:: isis fast-reroute ti-lfa [level-1|level-2] [node-protection]
 .. clicmd:: [no] isis fast-reroute ti-lfa [level-1|level-2] [node-protection]
 
@@ -430,6 +469,12 @@ Showing ISIS information
    Show the ISIS routing table, as determined by the most recent SPF
    calculation.
 
+.. index:: show isis fast-reroute summary [level-1|level-2]
+.. clicmd:: show isis fast-reroute summary [level-1|level-2]
+
+   Show information about the number of prefixes having LFA protection,
+   and network-wide LFA coverage.
+
 .. _isis-traffic-engineering:
 
 Traffic Engineering
@@ -641,13 +686,13 @@ Debugging ISIS
 
    IS-IS Segment Routing events.
 
-.. index:: debug isis ti-lfa
-.. clicmd:: debug isis ti-lfa
+.. index:: debug isis lfa
+.. clicmd:: debug isis lfa
 
-.. index:: debug isis ti-lfa
-.. clicmd:: no debug isis ti-lfa
+.. index:: debug isis lfa
+.. clicmd:: no debug isis lfa
 
-   IS-IS TI-LFA events.
+   IS-IS LFA events.
 
 .. index:: show debugging isis
 .. clicmd:: show debugging isis
diff --git a/isisd/isis_circuit.c b/isisd/isis_circuit.c
index e3c70264f..2580a7c43 100644
--- a/isisd/isis_circuit.c
+++ b/isisd/isis_circuit.c
@@ -140,6 +140,8 @@ struct isis_circuit *isis_circuit_new(struct isis *isis)
 #endif /* ifndef FABRICD */
 
 	circuit_mt_init(circuit);
+	isis_lfa_excluded_ifaces_init(circuit, ISIS_LEVEL1);
+	isis_lfa_excluded_ifaces_init(circuit, ISIS_LEVEL2);
 
 	QOBJ_REG(circuit, isis_circuit);
 
@@ -156,6 +158,8 @@ void isis_circuit_del(struct isis_circuit *circuit)
 	isis_circuit_if_unbind(circuit, circuit->interface);
 
 	circuit_mt_finish(circuit);
+	isis_lfa_excluded_ifaces_clear(circuit, ISIS_LEVEL1);
+	isis_lfa_excluded_ifaces_clear(circuit, ISIS_LEVEL2);
 
 	/* and lastly the circuit itself */
 	XFREE(MTYPE_ISIS_CIRCUIT, circuit);
diff --git a/isisd/isis_circuit.h b/isisd/isis_circuit.h
index b4b03bf6b..e736d8fb1 100644
--- a/isisd/isis_circuit.h
+++ b/isisd/isis_circuit.h
@@ -141,6 +141,8 @@ struct isis_circuit {
 	bool disable_threeway_adj;
 	struct bfd_info *bfd_info;
 	struct ldp_sync_info *ldp_sync_info;
+	bool lfa_protection[ISIS_LEVELS];
+	struct hash *lfa_excluded_ifaces[ISIS_LEVELS];
 	bool tilfa_protection[ISIS_LEVELS];
 	bool tilfa_node_protection[ISIS_LEVELS];
 	/*
diff --git a/isisd/isis_cli.c b/isisd/isis_cli.c
index 6c6d88ad5..1f0bebaf4 100644
--- a/isisd/isis_cli.c
+++ b/isisd/isis_cli.c
@@ -1137,6 +1137,54 @@ void cli_show_isis_spf_ietf_backoff(struct vty *vty, struct lyd_node *dnode,
 }
 
 /*
+ * XPath: /frr-isisd:isis/instance/spf/prefix-priorities/medium/access-list-name
+ */
+DEFPY_YANG(spf_prefix_priority, spf_prefix_priority_cmd,
+      "spf prefix-priority <critical|high|medium>$priority WORD$acl_name",
+      "SPF configuration\n"
+      "Configure a prefix priority list\n"
+      "Specify critical priority prefixes\n"
+      "Specify high priority prefixes\n"
+      "Specify medium priority prefixes\n"
+      "Access-list name\n")
+{
+	char xpath[XPATH_MAXLEN];
+
+	snprintf(xpath, XPATH_MAXLEN,
+		 "./spf/prefix-priorities/%s/access-list-name", priority);
+	nb_cli_enqueue_change(vty, xpath, NB_OP_CREATE, acl_name);
+
+	return nb_cli_apply_changes(vty, NULL);
+}
+
+DEFPY_YANG(no_spf_prefix_priority, no_spf_prefix_priority_cmd,
+      "no spf prefix-priority <critical|high|medium>$priority [WORD]",
+      NO_STR
+      "SPF configuration\n"
+      "Configure a prefix priority list\n"
+      "Specify critical priority prefixes\n"
+      "Specify high priority prefixes\n"
+      "Specify medium priority prefixes\n"
+      "Access-list name\n")
+{
+	char xpath[XPATH_MAXLEN];
+
+	snprintf(xpath, XPATH_MAXLEN,
+		 "./spf/prefix-priorities/%s/access-list-name", priority);
+	nb_cli_enqueue_change(vty, xpath, NB_OP_DESTROY, NULL);
+
+	return nb_cli_apply_changes(vty, NULL);
+}
+
+void cli_show_isis_spf_prefix_priority(struct vty *vty, struct lyd_node *dnode,
+				       bool show_defaults)
+{
+	vty_out(vty, " spf prefix-priority %s %s\n",
+		dnode->parent->schema->name,
+		yang_dnode_get_string(dnode, NULL));
+}
+
+/*
  * XPath: /frr-isisd:isis/instance/purge-originator
  */
 DEFPY_YANG(area_purge_originator, area_purge_originator_cmd, "[no] purge-originator",
@@ -1729,6 +1777,176 @@ void cli_show_isis_prefix_sid(struct vty *vty, struct lyd_node *dnode,
 	vty_out(vty, "\n");
 }
 
+
+/*
+ * XPath: /frr-isisd:isis/instance/fast-reroute/level-{1,2}/lfa/priority-limit
+ */
+DEFPY_YANG (isis_frr_lfa_priority_limit,
+       isis_frr_lfa_priority_limit_cmd,
+       "[no] fast-reroute priority-limit <critical|high|medium>$priority [<level-1|level-2>$level]",
+       NO_STR
+       "Configure Fast ReRoute\n"
+       "Limit backup computation up to the prefix priority\n"
+       "Compute for critical priority prefixes only\n"
+       "Compute for critical & high priority prefixes\n"
+       "Compute for critical, high & medium priority prefixes\n"
+       "Set priority-limit for level-1 only\n"
+       "Set priority-limit for level-2 only\n")
+{
+	if (!level || strmatch(level, "level-1")) {
+		if (no) {
+			nb_cli_enqueue_change(
+				vty,
+				"./fast-reroute/level-1/lfa/priority-limit",
+				NB_OP_DESTROY, NULL);
+		} else {
+			nb_cli_enqueue_change(
+				vty,
+				"./fast-reroute/level-1/lfa/priority-limit",
+				NB_OP_CREATE, priority);
+		}
+	}
+	if (!level || strmatch(level, "level-2")) {
+		if (no) {
+			nb_cli_enqueue_change(
+				vty,
+				"./fast-reroute/level-2/lfa/priority-limit",
+				NB_OP_DESTROY, NULL);
+		} else {
+			nb_cli_enqueue_change(
+				vty,
+				"./fast-reroute/level-2/lfa/priority-limit",
+				NB_OP_CREATE, priority);
+		}
+	}
+
+	return nb_cli_apply_changes(vty, NULL);
+}
+
+void cli_show_isis_frr_lfa_priority_limit(struct vty *vty,
+					  struct lyd_node *dnode,
+					  bool show_defaults)
+{
+	vty_out(vty, " fast-reroute priority-limit %s %s\n",
+		yang_dnode_get_string(dnode, NULL),
+		dnode->parent->parent->schema->name);
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/fast-reroute/level-{1,2}/lfa/tiebreaker
+ */
+DEFPY_YANG (isis_frr_lfa_tiebreaker,
+       isis_frr_lfa_tiebreaker_cmd,
+       "[no] fast-reroute lfa\
+          tiebreaker <downstream|lowest-backup-metric|node-protecting>$type\
+	  index (1-255)$index\
+	  [<level-1|level-2>$level]",
+       NO_STR
+       "Configure Fast ReRoute\n"
+       "LFA configuration\n"
+       "Configure tiebreaker for multiple backups\n"
+       "Prefer backup path via downstream node\n"
+       "Prefer backup path with lowest total metric\n"
+       "Prefer node protecting backup path\n"
+       "Set preference order among tiebreakers\n"
+       "Index\n"
+       "Configure tiebreaker for level-1 only\n"
+       "Configure tiebreaker for level-2 only\n")
+{
+	char xpath[XPATH_MAXLEN];
+
+	if (!level || strmatch(level, "level-1")) {
+		if (no) {
+			snprintf(
+				xpath, XPATH_MAXLEN,
+				"./fast-reroute/level-1/lfa/tiebreaker[index='%s']",
+				index_str);
+			nb_cli_enqueue_change(vty, xpath, NB_OP_DESTROY, NULL);
+		} else {
+			snprintf(
+				xpath, XPATH_MAXLEN,
+				"./fast-reroute/level-1/lfa/tiebreaker[index='%s']/type",
+				index_str);
+			nb_cli_enqueue_change(vty, xpath, NB_OP_CREATE, type);
+		}
+	}
+	if (!level || strmatch(level, "level-2")) {
+		if (no) {
+			snprintf(
+				xpath, XPATH_MAXLEN,
+				"./fast-reroute/level-2/lfa/tiebreaker[index='%s']",
+				index_str);
+			nb_cli_enqueue_change(vty, xpath, NB_OP_DESTROY, NULL);
+		} else {
+			snprintf(
+				xpath, XPATH_MAXLEN,
+				"./fast-reroute/level-2/lfa/tiebreaker[index='%s']/type",
+				index_str);
+			nb_cli_enqueue_change(vty, xpath, NB_OP_CREATE, type);
+		}
+	}
+
+	return nb_cli_apply_changes(vty, NULL);
+}
+
+void cli_show_isis_frr_lfa_tiebreaker(struct vty *vty, struct lyd_node *dnode,
+				      bool show_defaults)
+{
+	vty_out(vty, " fast-reroute lfa tiebreaker %s index %s %s\n",
+		yang_dnode_get_string(dnode, "./type"),
+		yang_dnode_get_string(dnode, "./index"),
+		dnode->parent->parent->schema->name);
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/fast-reroute/level-{1,2}/lfa/load-sharing
+ */
+DEFPY_YANG (isis_frr_lfa_load_sharing,
+       isis_frr_lfa_load_sharing_cmd,
+       "[no] fast-reroute load-sharing disable [<level-1|level-2>$level]",
+       NO_STR
+       "Configure Fast ReRoute\n"
+       "Load share prefixes across multiple backups\n"
+       "Disable load sharing\n"
+       "Disable load sharing for level-1 only\n"
+       "Disable load sharing for level-2 only\n")
+{
+	if (!level || strmatch(level, "level-1")) {
+		if (no) {
+			nb_cli_enqueue_change(
+				vty, "./fast-reroute/level-1/lfa/load-sharing",
+				NB_OP_DESTROY, "true");
+		} else {
+			nb_cli_enqueue_change(
+				vty, "./fast-reroute/level-1/lfa/load-sharing",
+				NB_OP_CREATE, "false");
+		}
+	}
+	if (!level || strmatch(level, "level-2")) {
+		if (no) {
+			nb_cli_enqueue_change(
+				vty, "./fast-reroute/level-2/lfa/load-sharing",
+				NB_OP_DESTROY, "true");
+		} else {
+			nb_cli_enqueue_change(
+				vty, "./fast-reroute/level-2/lfa/load-sharing",
+				NB_OP_CREATE, "false");
+		}
+	}
+
+	return nb_cli_apply_changes(vty, NULL);
+}
+
+void cli_show_isis_frr_lfa_load_sharing(struct vty *vty, struct lyd_node *dnode,
+					bool show_defaults)
+{
+	if (!yang_dnode_get_bool(dnode, NULL))
+		vty_out(vty, " no");
+
+	vty_out(vty, " fast-reroute load-sharing disable %s\n",
+		dnode->parent->parent->schema->name);
+}
+
 /*
  * XPath: /frr-interface:lib/interface/frr-isisd:isis/passive
  */
@@ -2386,7 +2604,164 @@ void cli_show_ip_isis_priority(struct vty *vty, struct lyd_node *dnode,
 }
 
 /*
- * XPath: /frr-interface:lib/interface/frr-isisd:isis/fast-reroute/ti-lfa/enable
+ * XPath: /frr-interface:lib/interface/frr-isisd:isis/fast-reroute
+ */
+void cli_show_ip_isis_frr(struct vty *vty, struct lyd_node *dnode,
+			  bool show_defaults)
+{
+	bool l1_enabled, l2_enabled;
+	bool l1_node_protection, l2_node_protection;
+
+	/* Classic LFA */
+	l1_enabled = yang_dnode_get_bool(dnode, "./level-1/lfa/enable");
+	l2_enabled = yang_dnode_get_bool(dnode, "./level-2/lfa/enable");
+
+	if (l1_enabled || l2_enabled) {
+		if (l1_enabled == l2_enabled) {
+			vty_out(vty, " isis fast-reroute lfa\n");
+			vty_out(vty, "\n");
+		} else {
+			if (l1_enabled)
+				vty_out(vty,
+					" isis fast-reroute lfa level-1\n");
+			if (l2_enabled)
+				vty_out(vty,
+					" isis fast-reroute lfa level-2\n");
+		}
+	}
+
+	/* TI-LFA */
+	l1_enabled = yang_dnode_get_bool(dnode, "./level-1/ti-lfa/enable");
+	l2_enabled = yang_dnode_get_bool(dnode, "./level-2/ti-lfa/enable");
+	l1_node_protection =
+		yang_dnode_get_bool(dnode, "./level-1/ti-lfa/node-protection");
+	l2_node_protection =
+		yang_dnode_get_bool(dnode, "./level-2/ti-lfa/node-protection");
+
+	if (l1_enabled || l2_enabled) {
+		if (l1_enabled == l2_enabled
+		    && l1_node_protection == l2_node_protection) {
+			vty_out(vty, " isis fast-reroute ti-lfa");
+			if (l1_node_protection)
+				vty_out(vty, " node-protection");
+			vty_out(vty, "\n");
+		} else {
+			if (l1_enabled) {
+				vty_out(vty,
+					" isis fast-reroute ti-lfa level-1");
+				if (l1_node_protection)
+					vty_out(vty, " node-protection");
+				vty_out(vty, "\n");
+			}
+			if (l2_enabled) {
+				vty_out(vty,
+					" isis fast-reroute ti-lfa level-2");
+				if (l2_node_protection)
+					vty_out(vty, " node-protection");
+				vty_out(vty, "\n");
+			}
+		}
+	}
+}
+
+/*
+ * XPath: /frr-interface:lib/interface/frr-isisd:isis/fast-reroute/level-{1,2}/lfa/enable
+ */
+DEFPY(isis_lfa, isis_lfa_cmd,
+      "[no] isis fast-reroute lfa [level-1|level-2]$level",
+      NO_STR
+      "IS-IS routing protocol\n"
+      "Interface IP Fast-reroute configuration\n"
+      "Enable LFA computation\n"
+      "Enable LFA computation for Level 1 only\n"
+      "Enable LFA computation for Level 2 only\n")
+{
+	if (!level || strmatch(level, "level-1")) {
+		if (no) {
+			nb_cli_enqueue_change(
+				vty,
+				"./frr-isisd:isis/fast-reroute/level-1/lfa/enable",
+				NB_OP_MODIFY, "false");
+		} else {
+			nb_cli_enqueue_change(
+				vty,
+				"./frr-isisd:isis/fast-reroute/level-1/lfa/enable",
+				NB_OP_MODIFY, "true");
+		}
+	}
+	if (!level || strmatch(level, "level-2")) {
+		if (no) {
+			nb_cli_enqueue_change(
+				vty,
+				"./frr-isisd:isis/fast-reroute/level-2/lfa/enable",
+				NB_OP_MODIFY, "false");
+		} else {
+			nb_cli_enqueue_change(
+				vty,
+				"./frr-isisd:isis/fast-reroute/level-2/lfa/enable",
+				NB_OP_MODIFY, "true");
+		}
+	}
+
+	return nb_cli_apply_changes(vty, NULL);
+}
+
+/*
+ * XPath:
+ * /frr-interface:lib/interface/frr-isisd:isis/fast-reroute/level-{1,2}/lfa/exclude-interface
+ */
+DEFPY(isis_lfa_exclude_interface, isis_lfa_exclude_interface_cmd,
+      "[no] isis fast-reroute lfa [level-1|level-2]$level exclude interface IFNAME$ifname",
+      NO_STR
+      "IS-IS routing protocol\n"
+      "Interface IP Fast-reroute configuration\n"
+      "Enable LFA computation\n"
+      "Enable LFA computation for Level 1 only\n"
+      "Enable LFA computation for Level 2 only\n"
+      "FRR exclusion information\n"
+      "Exclude an interface from computation\n"
+      "Interface name\n")
+{
+	if (!level || strmatch(level, "level-1")) {
+		if (no) {
+			nb_cli_enqueue_change(
+				vty,
+				"./frr-isisd:isis/fast-reroute/level-1/lfa/exclude-interface",
+				NB_OP_DESTROY, ifname);
+		} else {
+			nb_cli_enqueue_change(
+				vty,
+				"./frr-isisd:isis/fast-reroute/level-1/lfa/exclude-interface",
+				NB_OP_CREATE, ifname);
+		}
+	}
+	if (!level || strmatch(level, "level-2")) {
+		if (no) {
+			nb_cli_enqueue_change(
+				vty,
+				"./frr-isisd:isis/fast-reroute/level-2/lfa/exclude-interface",
+				NB_OP_DESTROY, ifname);
+		} else {
+			nb_cli_enqueue_change(
+				vty,
+				"./frr-isisd:isis/fast-reroute/level-2/lfa/exclude-interface",
+				NB_OP_CREATE, ifname);
+		}
+	}
+
+	return nb_cli_apply_changes(vty, NULL);
+}
+
+void cli_show_frr_lfa_exclude_interface(struct vty *vty, struct lyd_node *dnode,
+					bool show_defaults)
+{
+	vty_out(vty, " isis fast-reroute lfa %s exclude interface %s\n",
+		dnode->parent->parent->schema->name,
+		yang_dnode_get_string(dnode, NULL));
+}
+
+/*
+ * XPath: /frr-interface:lib/interface/frr-isisd:isis/fast-reroute/level-{1,2}/ti-lfa/enable
  */
 DEFPY(isis_ti_lfa, isis_ti_lfa_cmd,
       "[no] isis fast-reroute ti-lfa [level-1|level-2]$level [node-protection$node_protection]",
@@ -2446,41 +2821,6 @@ DEFPY(isis_ti_lfa, isis_ti_lfa_cmd,
 	return nb_cli_apply_changes(vty, NULL);
 }
 
-void cli_show_ip_isis_ti_lfa(struct vty *vty, struct lyd_node *dnode,
-			     bool show_defaults)
-{
-	bool l1_enabled, l2_enabled;
-	bool l1_node_protection, l2_node_protection;
-
-	l1_enabled = yang_dnode_get_bool(dnode, "./level-1/ti-lfa/enable");
-	l2_enabled = yang_dnode_get_bool(dnode, "./level-2/ti-lfa/enable");
-	l1_node_protection =
-		yang_dnode_get_bool(dnode, "./level-1/ti-lfa/node-protection");
-	l2_node_protection =
-		yang_dnode_get_bool(dnode, "./level-2/ti-lfa/node-protection");
-
-	if (l1_enabled == l2_enabled
-	    && l1_node_protection == l2_node_protection) {
-		vty_out(vty, " isis fast-reroute ti-lfa");
-		if (l1_node_protection)
-			vty_out(vty, " node-protection");
-		vty_out(vty, "\n");
-	} else {
-		if (l1_enabled) {
-			vty_out(vty, " isis fast-reroute ti-lfa level-1");
-			if (l1_node_protection)
-				vty_out(vty, " node-protection");
-			vty_out(vty, "\n");
-		}
-		if (l2_enabled) {
-			vty_out(vty, " isis fast-reroute ti-lfa level-2");
-			if (l2_node_protection)
-				vty_out(vty, " node-protection");
-			vty_out(vty, "\n");
-		}
-	}
-}
-
 /*
  * XPath: /frr-isisd:isis/instance/log-adjacency-changes
  */
@@ -2714,6 +3054,8 @@ void isis_cli_init(void)
 
 	install_element(ISIS_NODE, &spf_interval_cmd);
 	install_element(ISIS_NODE, &no_spf_interval_cmd);
+	install_element(ISIS_NODE, &spf_prefix_priority_cmd);
+	install_element(ISIS_NODE, &no_spf_prefix_priority_cmd);
 	install_element(ISIS_NODE, &spf_delay_ietf_cmd);
 	install_element(ISIS_NODE, &no_spf_delay_ietf_cmd);
 
@@ -2740,6 +3082,9 @@ void isis_cli_init(void)
 	install_element(ISIS_NODE, &no_isis_sr_node_msd_cmd);
 	install_element(ISIS_NODE, &isis_sr_prefix_sid_cmd);
 	install_element(ISIS_NODE, &no_isis_sr_prefix_sid_cmd);
+	install_element(ISIS_NODE, &isis_frr_lfa_priority_limit_cmd);
+	install_element(ISIS_NODE, &isis_frr_lfa_tiebreaker_cmd);
+	install_element(ISIS_NODE, &isis_frr_lfa_load_sharing_cmd);
 
 	install_element(INTERFACE_NODE, &isis_passive_cmd);
 
@@ -2775,6 +3120,8 @@ void isis_cli_init(void)
 	install_element(INTERFACE_NODE, &isis_priority_cmd);
 	install_element(INTERFACE_NODE, &no_isis_priority_cmd);
 
+	install_element(INTERFACE_NODE, &isis_lfa_cmd);
+	install_element(INTERFACE_NODE, &isis_lfa_exclude_interface_cmd);
 	install_element(INTERFACE_NODE, &isis_ti_lfa_cmd);
 
 	install_element(ISIS_NODE, &log_adj_changes_cmd);
diff --git a/isisd/isis_ldp_sync.c b/isisd/isis_ldp_sync.c
index 988af64c4..3b1faffe5 100644
--- a/isisd/isis_ldp_sync.c
+++ b/isisd/isis_ldp_sync.c
@@ -429,20 +429,24 @@ void isis_ldp_sync_set_if_metric(struct isis_circuit *circuit, bool run_regen)
 			if (circuit->area->newmetric) {
 				ldp_sync_info->metric[0] =
 					circuit->te_metric[0];
-				circuit->te_metric[0] = LDP_ISIS_LSINFINITY;
+				circuit->te_metric[0] =
+					ISIS_WIDE_METRIC_INFINITY;
 			} else {
 				ldp_sync_info->metric[0] = circuit->metric[0];
-				circuit->metric[0] = LDP_ISIS_LSINFINITY_NL;
+				circuit->metric[0] =
+					ISIS_NARROW_METRIC_INFINITY;
 			}
 		}
 		if (circuit->is_type & IS_LEVEL_2) {
 			if (circuit->area->newmetric) {
 				ldp_sync_info->metric[1] =
 					circuit->te_metric[1];
-				circuit->te_metric[1] = LDP_ISIS_LSINFINITY;
+				circuit->te_metric[1] =
+					ISIS_WIDE_METRIC_INFINITY;
 			} else {
 				ldp_sync_info->metric[1] = circuit->metric[1];
-				circuit->metric[1] = LDP_ISIS_LSINFINITY_NL;
+				circuit->metric[1] =
+					ISIS_NARROW_METRIC_INFINITY;
 			}
 		}
 	} else {
diff --git a/isisd/isis_ldp_sync.h b/isisd/isis_ldp_sync.h
index 6017cdf00..61ac94607 100644
--- a/isisd/isis_ldp_sync.h
+++ b/isisd/isis_ldp_sync.h
@@ -20,9 +20,6 @@
 #ifndef _ZEBRA_ISIS_LDP_SYNC_H
 #define _ZEBRA_ISIS_LDP_SYNC_H
 
-#define LDP_ISIS_LSINFINITY 0xFFFFFE  /* wide link metric */
-#define LDP_ISIS_LSINFINITY_NL 62     /* narrow link metric */
-
 /* Macro to log debug message */
 #define ils_debug(...)                                                         \
 	do {                                                                   \
diff --git a/isisd/isis_lfa.c b/isisd/isis_lfa.c
index f22e4a708..fc6b435b6 100644
--- a/isisd/isis_lfa.c
+++ b/isisd/isis_lfa.c
@@ -40,6 +40,8 @@
 #include "isisd/isis_errors.h"
 
 DEFINE_MTYPE_STATIC(ISISD, ISIS_SPF_NODE, "ISIS SPF Node");
+DEFINE_MTYPE_STATIC(ISISD, ISIS_LFA_TIEBREAKER, "ISIS LFA Tiebreaker");
+DEFINE_MTYPE_STATIC(ISISD, ISIS_LFA_EXCL_IFACE, "ISIS LFA Excluded Interface");
 
 static inline int isis_spf_node_compare(const struct isis_spf_node *a,
 					const struct isis_spf_node *b)
@@ -120,6 +122,185 @@ struct isis_spf_node *isis_spf_node_find(const struct isis_spf_nodes *nodes,
 }
 
 /**
+ * LFA tiebreaker RB-tree comparison function.
+ *
+ * @param a	First LFA tiebreaker
+ * @param b	Second LFA tiebreaker
+ *
+ * @return	-1 (a < b), 0 (a == b) or +1 (a > b)
+ */
+int lfa_tiebreaker_cmp(const struct lfa_tiebreaker *a,
+		       const struct lfa_tiebreaker *b)
+{
+	if (a->index < b->index)
+		return -1;
+	if (a->index > b->index)
+		return 1;
+
+	return a->type - b->type;
+}
+
+/**
+ * Initialize list of LFA tie-breakers.
+ *
+ * @param area		IS-IS area
+ * @param level		IS-IS level
+ */
+void isis_lfa_tiebreakers_init(struct isis_area *area, int level)
+{
+	lfa_tiebreaker_tree_init(&area->lfa_tiebreakers[level - 1]);
+}
+
+/**
+ * Clear list of LFA tie-breakers, releasing all allocated memory.
+ *
+ * @param area		IS-IS area
+ * @param level		IS-IS level
+ */
+void isis_lfa_tiebreakers_clear(struct isis_area *area, int level)
+{
+	while (lfa_tiebreaker_tree_count(&area->lfa_tiebreakers[level - 1])
+	       > 0) {
+		struct lfa_tiebreaker *tie_b;
+
+		tie_b = lfa_tiebreaker_tree_first(
+			&area->lfa_tiebreakers[level - 1]);
+		isis_lfa_tiebreaker_delete(area, level, tie_b);
+	}
+}
+
+/**
+ * Add new LFA tie-breaker to list of LFA tie-breakers.
+ *
+ * @param area		IS-IS area
+ * @param level		IS-IS level
+ * @param index		LFA tie-breaker index
+ * @param type		LFA tie-breaker type
+ *
+ * @return		Pointer to new LFA tie-breaker structure.
+ */
+struct lfa_tiebreaker *isis_lfa_tiebreaker_add(struct isis_area *area,
+					       int level, uint8_t index,
+					       enum lfa_tiebreaker_type type)
+{
+	struct lfa_tiebreaker *tie_b;
+
+	tie_b = XCALLOC(MTYPE_ISIS_LFA_TIEBREAKER, sizeof(*tie_b));
+	tie_b->index = index;
+	tie_b->type = type;
+	tie_b->area = area;
+	lfa_tiebreaker_tree_add(&area->lfa_tiebreakers[level - 1], tie_b);
+
+	return tie_b;
+}
+
+/**
+ * Remove LFA tie-breaker from list of LFA tie-breakers.
+ *
+ * @param area		IS-IS area
+ * @param level		IS-IS level
+ * @param tie_b		Pointer to LFA tie-breaker structure
+ */
+void isis_lfa_tiebreaker_delete(struct isis_area *area, int level,
+				struct lfa_tiebreaker *tie_b)
+{
+	lfa_tiebreaker_tree_del(&area->lfa_tiebreakers[level - 1], tie_b);
+	XFREE(MTYPE_ISIS_LFA_TIEBREAKER, tie_b);
+}
+
+static bool lfa_excl_interface_hash_cmp(const void *value1, const void *value2)
+{
+	return strmatch(value1, value2);
+}
+
+static unsigned int lfa_excl_interface_hash_make(const void *value)
+{
+	return string_hash_make(value);
+}
+
+static void *lfa_excl_interface_hash_alloc(void *p)
+{
+	return XSTRDUP(MTYPE_ISIS_LFA_EXCL_IFACE, p);
+}
+
+static void lfa_excl_interface_hash_free(void *arg)
+{
+	XFREE(MTYPE_ISIS_LFA_EXCL_IFACE, arg);
+}
+
+/**
+ * Initialize hash table of LFA excluded interfaces.
+ *
+ * @param circuit	IS-IS interface
+ * @param level		IS-IS level
+ */
+void isis_lfa_excluded_ifaces_init(struct isis_circuit *circuit, int level)
+{
+	circuit->lfa_excluded_ifaces[level - 1] = hash_create(
+		lfa_excl_interface_hash_make, lfa_excl_interface_hash_cmp,
+		"LFA Excluded Interfaces");
+}
+
+/**
+ * Clear hash table of LFA excluded interfaces, releasing all allocated memory.
+ *
+ * @param nodes		List of SPF nodes
+ */
+void isis_lfa_excluded_ifaces_clear(struct isis_circuit *circuit, int level)
+{
+	hash_clean(circuit->lfa_excluded_ifaces[level - 1],
+		   lfa_excl_interface_hash_free);
+}
+
+/**
+ * Add new interface to hash table of excluded interfaces.
+ *
+ * @param circuit	IS-IS interface
+ * @param level		IS-IS level
+ * @param ifname	Excluded interface name
+ */
+void isis_lfa_excluded_iface_add(struct isis_circuit *circuit, int level,
+				 const char *ifname)
+{
+	hash_get(circuit->lfa_excluded_ifaces[level - 1], (char *)ifname,
+		 lfa_excl_interface_hash_alloc);
+}
+
+/**
+ * Remove interface from hash table of excluded interfaces.
+ *
+ * @param circuit	IS-IS interface
+ * @param level		IS-IS level
+ * @param ifname	Excluded interface name
+ */
+void isis_lfa_excluded_iface_delete(struct isis_circuit *circuit, int level,
+				    const char *ifname)
+{
+	char *found;
+
+	found = hash_lookup(circuit->lfa_excluded_ifaces[level - 1],
+			    (char *)ifname);
+	if (found) {
+		hash_release(circuit->lfa_excluded_ifaces[level - 1], found);
+		lfa_excl_interface_hash_free(found);
+	}
+}
+
+/**
+ * Lookup excluded interface.
+ *
+ * @param circuit	IS-IS interface
+ * @param level		IS-IS level
+ * @param ifname	Excluded interface name
+ */
+bool isis_lfa_excluded_iface_check(struct isis_circuit *circuit, int level,
+				   const char *ifname)
+{
+	return hash_lookup(circuit->lfa_excluded_ifaces[level - 1],
+			   (char *)ifname);
+}
+
+/**
  * Check if a given IS-IS adjacency needs to be excised when computing the SPF
  * post-convergence tree.
  *
@@ -438,10 +619,10 @@ static int tilfa_build_repair_list(struct isis_spftree *spftree_pc,
 	uint32_t sid_index;
 	mpls_label_t label_qnode;
 
-	if (IS_DEBUG_TILFA) {
+	if (IS_DEBUG_LFA) {
 		vid2string(vertex, buf, sizeof(buf));
-		zlog_debug("ISIS-TI-LFA: vertex %s %s",
-			   vtype2string(vertex->type), buf);
+		zlog_debug("ISIS-LFA: vertex %s %s", vtype2string(vertex->type),
+			   buf);
 	}
 
 	/* Push original Prefix-SID label when necessary. */
@@ -450,9 +631,9 @@ static int tilfa_build_repair_list(struct isis_spftree *spftree_pc,
 		assert(pvertex);
 
 		sid_index = vertex->N.ip.sr.sid.value;
-		if (IS_DEBUG_TILFA)
+		if (IS_DEBUG_LFA)
 			zlog_debug(
-				"ISIS-TI-LFA: pushing Prefix-SID to %pFX (index %u)",
+				"ISIS-LFA: pushing Prefix-SID to %pFX (index %u)",
 				&vertex->N.ip.p.dest, sid_index);
 		sid_dest.type = TILFA_SID_PREFIX;
 		sid_dest.value.index.value = sid_index;
@@ -481,14 +662,14 @@ static int tilfa_build_repair_list(struct isis_spftree *spftree_pc,
 		label_qnode = tilfa_find_qnode_adj_sid(spftree_pc, vertex->N.id,
 						       vertex_child->N.id);
 		if (label_qnode == MPLS_INVALID_LABEL) {
-			zlog_warn("ISIS-TI-LFA: failed to find %s->%s Adj-SID",
+			zlog_warn("ISIS-LFA: failed to find %s->%s Adj-SID",
 				  print_sys_hostname(vertex->N.id),
 				  print_sys_hostname(vertex_child->N.id));
 			return -1;
 		}
-		if (IS_DEBUG_TILFA)
+		if (IS_DEBUG_LFA)
 			zlog_debug(
-				"ISIS-TI-LFA: pushing %s->%s Adj-SID (label %u)",
+				"ISIS-LFA: pushing %s->%s Adj-SID (label %u)",
 				print_sys_hostname(vertex->N.id),
 				print_sys_hostname(vertex_child->N.id),
 				label_qnode);
@@ -501,17 +682,17 @@ static int tilfa_build_repair_list(struct isis_spftree *spftree_pc,
 	if (is_pnode) {
 		/* The same P-node can't be used more than once. */
 		if (isis_spf_node_find(used_pnodes, vertex->N.id)) {
-			if (IS_DEBUG_TILFA)
+			if (IS_DEBUG_LFA)
 				zlog_debug(
-					"ISIS-TI-LFA: skipping already used P-node");
+					"ISIS-LFA: skipping already used P-node");
 			return 0;
 		}
 		isis_spf_node_new(used_pnodes, vertex->N.id);
 
 		if (!vertex_child) {
-			if (IS_DEBUG_TILFA)
+			if (IS_DEBUG_LFA)
 				zlog_debug(
-					"ISIS-TI-LFA: destination is within Ext-P-Space");
+					"ISIS-LFA: destination is within Ext-P-Space");
 			return 0;
 		}
 
@@ -519,20 +700,29 @@ static int tilfa_build_repair_list(struct isis_spftree *spftree_pc,
 			tilfa_find_pnode_prefix_sid(spftree_pc, vertex->N.id);
 		if (sid_index == UINT32_MAX) {
 			zlog_warn(
-				"ISIS-TI-LFA: failed to find Prefix-SID corresponding to PQ-node %s",
+				"ISIS-LFA: failed to find Prefix-SID corresponding to PQ-node %s",
 				print_sys_hostname(vertex->N.id));
 			return -1;
 		}
 
-		if (IS_DEBUG_TILFA)
+		if (IS_DEBUG_LFA)
 			zlog_debug(
-				"ISIS-TI-LFA: pushing Node-SID to %s (index %u)",
+				"ISIS-LFA: pushing Node-SID to %s (index %u)",
 				print_sys_hostname(vertex->N.id), sid_index);
 		sid_pnode.type = TILFA_SID_PREFIX;
 		sid_pnode.value.index.value = sid_index;
 		listnode_add_head(repair_list, &sid_pnode);
 
 		/* Apply repair list. */
+		if (spftree_pc->area->srdb.config.msd
+		    && listcount(repair_list)
+			       > spftree_pc->area->srdb.config.msd) {
+			zlog_warn(
+				"ISIS-LFA: list of repair segments exceeds locally configured MSD (%u > %u)",
+				listcount(repair_list),
+				spftree_pc->area->srdb.config.msd);
+			return -1;
+		}
 		if (tilfa_repair_list_apply(spftree_pc, vertex_dest, vertex,
 					    repair_list)
 		    != 0)
@@ -610,36 +800,25 @@ spf_adj_check_is_affected(const struct isis_spf_adj *sadj,
 	return false;
 }
 
-/* Check if the given SPF vertex needs LFA protection. */
-static bool lfa_check_needs_protection(const struct isis_spftree *spftree_pc,
-				       const struct isis_vertex *vertex)
+/* Check if the given vertex is affected by a given local failure. */
+static bool
+spf_vertex_check_is_affected(const struct isis_vertex *vertex,
+			     const uint8_t *root_sysid,
+			     const struct lfa_protected_resource *resource)
 {
-	struct isis_vertex *vertex_old;
+	struct isis_vertex_adj *vadj;
 	struct listnode *node;
 	size_t affected_nhs = 0;
-	struct isis_vertex_adj *vadj;
 
 	/* Local routes don't need protection. */
 	if (VTYPE_IP(vertex->type) && vertex->depth == 1)
 		return false;
 
-	/* Only local adjacencies need Adj-SID protection. */
-	if (VTYPE_IS(vertex->type)
-	    && !isis_adj_find(spftree_pc->area, spftree_pc->level,
-			      vertex->N.id))
-		return false;
-
-	vertex_old = isis_find_vertex(&spftree_pc->lfa.old.spftree->paths,
-				      &vertex->N, vertex->type);
-	if (!vertex_old)
-		return false;
-
-	for (ALL_LIST_ELEMENTS_RO(vertex_old->Adj_N, node, vadj)) {
+	for (ALL_LIST_ELEMENTS_RO(vertex->Adj_N, node, vadj)) {
 		struct isis_spf_adj *sadj = vadj->sadj;
 
-		if (spf_adj_check_is_affected(
-			    sadj, &spftree_pc->lfa.protected_resource,
-			    spftree_pc->sysid, false))
+		if (spf_adj_check_is_affected(sadj, resource, root_sysid,
+					      false))
 			affected_nhs++;
 	}
 
@@ -647,12 +826,34 @@ static bool lfa_check_needs_protection(const struct isis_spftree *spftree_pc,
 	 * No need to compute backup paths for ECMP routes, except if all
 	 * primary nexthops share the same broadcast interface.
 	 */
-	if (listcount(vertex_old->Adj_N) == affected_nhs)
+	if (listcount(vertex->Adj_N) == affected_nhs)
 		return true;
 
 	return false;
 }
 
+/* Check if a given TI-LFA post-convergence SPF vertex needs protection. */
+static bool tilfa_check_needs_protection(const struct isis_spftree *spftree_pc,
+					 const struct isis_vertex *vertex)
+{
+	struct isis_vertex *vertex_old;
+
+	/* Only local adjacencies need Adj-SID protection. */
+	if (VTYPE_IS(vertex->type)
+	    && !isis_adj_find(spftree_pc->area, spftree_pc->level,
+			      vertex->N.id))
+		return false;
+
+	vertex_old = isis_find_vertex(&spftree_pc->lfa.old.spftree->paths,
+				      &vertex->N, vertex->type);
+	if (!vertex_old)
+		return false;
+
+	return spf_vertex_check_is_affected(
+		vertex_old, spftree_pc->sysid,
+		&spftree_pc->lfa.protected_resource);
+}
+
 /**
  * Check if the given SPF vertex needs protection and, if so, compute and
  * install the corresponding repair paths.
@@ -662,7 +863,8 @@ static bool lfa_check_needs_protection(const struct isis_spftree *spftree_pc,
  *
  * @return		0 if the vertex needs to be protected, -1 otherwise
  */
-int isis_lfa_check(struct isis_spftree *spftree_pc, struct isis_vertex *vertex)
+int isis_tilfa_check(struct isis_spftree *spftree_pc,
+		     struct isis_vertex *vertex)
 {
 	struct isis_spf_nodes used_pnodes;
 	char buf[VID2STR_BUFFER];
@@ -672,13 +874,13 @@ int isis_lfa_check(struct isis_spftree *spftree_pc, struct isis_vertex *vertex)
 	if (!spftree_pc->area->srdb.enabled)
 		return -1;
 
-	if (IS_DEBUG_TILFA)
+	if (IS_DEBUG_LFA)
 		vid2string(vertex, buf, sizeof(buf));
 
-	if (!lfa_check_needs_protection(spftree_pc, vertex)) {
-		if (IS_DEBUG_TILFA)
+	if (!tilfa_check_needs_protection(spftree_pc, vertex)) {
+		if (IS_DEBUG_LFA)
 			zlog_debug(
-				"ISIS-TI-LFA: %s %s unaffected by %s",
+				"ISIS-LFA: %s %s unaffected by %s",
 				vtype2string(vertex->type), buf,
 				lfa_protected_resource2str(
 					&spftree_pc->lfa.protected_resource));
@@ -697,9 +899,9 @@ int isis_lfa_check(struct isis_spftree *spftree_pc, struct isis_vertex *vertex)
 		if (adj
 		    && isis_sr_adj_sid_find(adj, spftree_pc->family,
 					    ISIS_SR_LAN_BACKUP)) {
-			if (IS_DEBUG_TILFA)
+			if (IS_DEBUG_LFA)
 				zlog_debug(
-					"ISIS-TI-LFA: %s %s already covered by node protection",
+					"ISIS-LFA: %s %s already covered by node protection",
 					vtype2string(vertex->type), buf);
 
 			return -1;
@@ -710,18 +912,18 @@ int isis_lfa_check(struct isis_spftree *spftree_pc, struct isis_vertex *vertex)
 
 		route_table = spftree_pc->lfa.old.spftree->route_table_backup;
 		if (route_node_lookup(route_table, &vertex->N.ip.p.dest)) {
-			if (IS_DEBUG_TILFA)
+			if (IS_DEBUG_LFA)
 				zlog_debug(
-					"ISIS-TI-LFA: %s %s already covered by node protection",
+					"ISIS-LFA: %s %s already covered by node protection",
 					vtype2string(vertex->type), buf);
 
 			return -1;
 		}
 	}
 
-	if (IS_DEBUG_TILFA)
+	if (IS_DEBUG_LFA)
 		zlog_debug(
-			"ISIS-TI-LFA: computing repair path(s) of %s %s w.r.t %s",
+			"ISIS-LFA: computing repair path(s) of %s %s w.r.t %s",
 			vtype2string(vertex->type), buf,
 			lfa_protected_resource2str(
 				&spftree_pc->lfa.protected_resource));
@@ -735,7 +937,11 @@ int isis_lfa_check(struct isis_spftree *spftree_pc, struct isis_vertex *vertex)
 	isis_spf_node_list_clear(&used_pnodes);
 	list_delete(&repair_list);
 	if (ret != 0)
-		zlog_warn("ISIS-TI-LFA: failed to compute repair path(s)");
+		zlog_warn(
+			"ISIS-LFA: failed to compute repair path(s) of %s %s w.r.t %s",
+			vtype2string(vertex->type), buf,
+			lfa_protected_resource2str(
+				&spftree_pc->lfa.protected_resource));
 
 	return ret;
 }
@@ -775,8 +981,8 @@ static bool vertex_is_affected(struct isis_spftree *spftree_root,
 		char buf1[VID2STR_BUFFER];
 		char buf2[VID2STR_BUFFER];
 
-		if (IS_DEBUG_TILFA)
-			zlog_debug("ISIS-TI-LFA: vertex %s parent %s",
+		if (IS_DEBUG_LFA)
+			zlog_debug("ISIS-LFA: vertex %s parent %s",
 				   vid2string(vertex, buf1, sizeof(buf1)),
 				   vid2string(pvertex, buf2, sizeof(buf2)));
 
@@ -853,15 +1059,15 @@ static void lfa_calc_reach_nodes(struct isis_spftree *spftree,
 		if (isis_spf_node_find(nodes, vertex->N.id))
 			continue;
 
-		if (IS_DEBUG_TILFA)
-			zlog_debug("ISIS-TI-LFA: checking %s",
+		if (IS_DEBUG_LFA)
+			zlog_debug("ISIS-LFA: checking %s",
 				   vid2string(vertex, buf, sizeof(buf)));
 
 		if (!vertex_is_affected(spftree_root, adj_nodes, p_space,
 					vertex, resource)) {
-			if (IS_DEBUG_TILFA)
+			if (IS_DEBUG_LFA)
 				zlog_debug(
-					"ISIS-TI-LFA: adding %s",
+					"ISIS-LFA: adding %s",
 					vid2string(vertex, buf, sizeof(buf)));
 
 			isis_spf_node_new(nodes, vertex->N.id);
@@ -875,7 +1081,7 @@ static void lfa_calc_reach_nodes(struct isis_spftree *spftree,
  *
  * @param spftree	IS-IS SPF tree
  *
- * @return		Pointer to new SPF tree structure. 
+ * @return		Pointer to new SPF tree structure.
  */
 struct isis_spftree *isis_spf_reverse_run(const struct isis_spftree *spftree)
 {
@@ -907,18 +1113,17 @@ static void lfa_calc_pq_spaces(struct isis_spftree *spftree_pc,
 	spftree_reverse = spftree_pc->lfa.old.spftree_reverse;
 	adj_nodes = &spftree->adj_nodes;
 
-	if (IS_DEBUG_TILFA)
-		zlog_debug("ISIS-TI-LFA: computing P-space (self)");
+	if (IS_DEBUG_LFA)
+		zlog_debug("ISIS-LFA: computing P-space (self)");
 	lfa_calc_reach_nodes(spftree, spftree, adj_nodes, true, resource,
 			     &spftree_pc->lfa.p_space);
 
 	RB_FOREACH (adj_node, isis_spf_nodes, adj_nodes) {
 		if (spf_adj_node_is_affected(adj_node, resource,
 					     spftree->sysid)) {
-			if (IS_DEBUG_TILFA)
-				zlog_debug(
-					"ISIS-TI-LFA: computing Q-space (%s)",
-					print_sys_hostname(adj_node->sysid));
+			if (IS_DEBUG_LFA)
+				zlog_debug("ISIS-LFA: computing Q-space (%s)",
+					   print_sys_hostname(adj_node->sysid));
 
 			/*
 			 * Compute the reverse SPF in the behalf of the node
@@ -932,10 +1137,9 @@ static void lfa_calc_pq_spaces(struct isis_spftree *spftree_pc,
 					     resource,
 					     &spftree_pc->lfa.q_space);
 		} else {
-			if (IS_DEBUG_TILFA)
-				zlog_debug(
-					"ISIS-TI-LFA: computing P-space (%s)",
-					print_sys_hostname(adj_node->sysid));
+			if (IS_DEBUG_LFA)
+				zlog_debug("ISIS-LFA: computing P-space (%s)",
+					   print_sys_hostname(adj_node->sysid));
 			lfa_calc_reach_nodes(adj_node->lfa.spftree, spftree,
 					     adj_nodes, true, resource,
 					     &adj_node->lfa.p_space);
@@ -961,8 +1165,8 @@ struct isis_spftree *isis_tilfa_compute(struct isis_area *area,
 	struct isis_spftree *spftree_pc;
 	struct isis_spf_node *adj_node;
 
-	if (IS_DEBUG_TILFA)
-		zlog_debug("ISIS-TI-LFA: computing the P/Q spaces w.r.t. %s",
+	if (IS_DEBUG_LFA)
+		zlog_debug("ISIS-LFA: computing the P/Q spaces w.r.t. %s",
 			   lfa_protected_resource2str(resource));
 
 	/* Populate list of nodes affected by link failure. */
@@ -987,9 +1191,9 @@ struct isis_spftree *isis_tilfa_compute(struct isis_area *area,
 	/* Compute the extended P-space and Q-space. */
 	lfa_calc_pq_spaces(spftree_pc, resource);
 
-	if (IS_DEBUG_TILFA)
+	if (IS_DEBUG_LFA)
 		zlog_debug(
-			"ISIS-TI-LFA: computing the post convergence SPT w.r.t. %s",
+			"ISIS-LFA: computing the post convergence SPT w.r.t. %s",
 			lfa_protected_resource2str(resource));
 
 	/* Re-run SPF in the local node to find the post-convergence paths. */
@@ -1019,8 +1223,8 @@ int isis_spf_run_neighbors(struct isis_spftree *spftree)
 		return -1;
 
 	RB_FOREACH (adj_node, isis_spf_nodes, &spftree->adj_nodes) {
-		if (IS_DEBUG_TILFA)
-			zlog_debug("ISIS-TI-LFA: running SPF on neighbor %s",
+		if (IS_DEBUG_LFA)
+			zlog_debug("ISIS-LFA: running SPF on neighbor %s",
 				   print_sys_hostname(adj_node->sysid));
 
 		/* Compute the SPT on behalf of the neighbor. */
@@ -1034,20 +1238,532 @@ int isis_spf_run_neighbors(struct isis_spftree *spftree)
 	return 0;
 }
 
+/* Calculate the distance from the root node to the given IP destination. */
+static int lfa_calc_dist_destination(struct isis_spftree *spftree,
+				     const struct isis_vertex *vertex_N,
+				     uint32_t *distance)
+{
+	struct isis_vertex *vertex, *vertex_best = NULL;
+
+	switch (spftree->family) {
+	case AF_INET:
+		for (int vtype = VTYPE_IPREACH_INTERNAL;
+		     vtype <= VTYPE_IPREACH_TE; vtype++) {
+			vertex = isis_find_vertex(
+				&spftree->paths, &vertex_N->N.ip.p.dest, vtype);
+			if (!vertex)
+				continue;
+
+			/* Pick vertex with the best metric. */
+			if (!vertex_best || vertex_best->d_N > vertex->d_N)
+				vertex_best = vertex;
+		}
+		break;
+	case AF_INET6:
+		for (int vtype = VTYPE_IP6REACH_INTERNAL;
+		     vtype <= VTYPE_IP6REACH_EXTERNAL; vtype++) {
+			vertex = isis_find_vertex(
+				&spftree->paths, &vertex_N->N.ip.p.dest, vtype);
+			if (!vertex)
+				continue;
+
+			/* Pick vertex with the best metric. */
+			if (!vertex_best || vertex_best->d_N > vertex->d_N)
+				vertex_best = vertex;
+		}
+		break;
+	default:
+		break;
+	}
+
+	if (!vertex_best)
+		return -1;
+
+	assert(VTYPE_IP(vertex_best->type));
+	vertex_best = listnode_head(vertex_best->parents);
+	*distance = vertex_best->d_N;
+
+	return 0;
+}
+
+/* Calculate the distance from the root node to the given node. */
+static int lfa_calc_dist_node(struct isis_spftree *spftree,
+			      const uint8_t *sysid, uint32_t *distance)
+{
+	struct isis_vertex *vertex, *vertex_best = NULL;
+
+	for (int vtype = VTYPE_PSEUDO_IS; vtype <= VTYPE_NONPSEUDO_TE_IS;
+	     vtype++) {
+		vertex = isis_find_vertex(&spftree->paths, sysid, vtype);
+		if (!vertex)
+			continue;
+
+		/* Pick vertex with the best metric. */
+		if (!vertex_best || vertex_best->d_N > vertex->d_N)
+			vertex_best = vertex;
+	}
+
+	if (!vertex_best)
+		return -1;
+
+	*distance = vertex_best->d_N;
+
+	return 0;
+}
+
+/*
+ * Check loop-free criterion (RFC 5286's inequality 1):
+ * - Dist_opt(N, D) < Dist_opt(N, S) + Dist_opt(S, D)
+ */
+static bool clfa_loop_free_check(struct isis_spftree *spftree,
+				 struct isis_vertex *vertex_S_D,
+				 struct isis_spf_adj *sadj_primary,
+				 struct isis_spf_adj *sadj_N,
+				 uint32_t *lfa_metric)
+{
+	struct isis_spf_node *node_N;
+	uint32_t dist_N_D;
+	uint32_t dist_N_S;
+	uint32_t dist_S_D;
+
+	node_N = isis_spf_node_find(&spftree->adj_nodes, sadj_N->id);
+	assert(node_N);
+
+	/* Distance from N to D. */
+	if (lfa_calc_dist_destination(node_N->lfa.spftree, vertex_S_D,
+				      &dist_N_D)
+	    != 0)
+		return false;
+
+	/* Distance from N to S (or PN). */
+	if (CHECK_FLAG(sadj_primary->flags, F_ISIS_SPF_ADJ_BROADCAST)) {
+		static uint8_t pn_sysid[ISIS_SYS_ID_LEN + 1];
+
+		memcpy(pn_sysid, sadj_primary->id, ISIS_SYS_ID_LEN + 1);
+		if (lfa_calc_dist_node(node_N->lfa.spftree, pn_sysid, &dist_N_S)
+		    != 0)
+			return false;
+	} else {
+		static uint8_t root_sysid[ISIS_SYS_ID_LEN + 1];
+
+		memcpy(root_sysid, spftree->sysid, ISIS_SYS_ID_LEN);
+		LSP_PSEUDO_ID(root_sysid) = 0;
+		if (lfa_calc_dist_node(node_N->lfa.spftree, root_sysid,
+				       &dist_N_S)
+		    != 0)
+			return false;
+	}
+
+	/* Distance from S (or PN) to D. */
+	vertex_S_D = listnode_head(vertex_S_D->parents);
+	dist_S_D = vertex_S_D->d_N;
+	if (CHECK_FLAG(sadj_primary->flags, F_ISIS_SPF_ADJ_BROADCAST))
+		dist_S_D -= sadj_primary->metric;
+
+	if (IS_DEBUG_LFA)
+		zlog_debug("ISIS-LFA: loop-free check: %u < %u + %u", dist_N_D,
+			   dist_N_S, dist_S_D);
+
+	if (dist_N_D < (dist_N_S + dist_S_D)) {
+		*lfa_metric = sadj_N->metric + dist_N_D;
+		return true;
+	}
+
+	return false;
+}
+
+/*
+ * Check loop-free criterion (RFC 5286's inequality 2):
+ * - Distance_opt(N, D) < Distance_opt(S, D)
+ */
+static bool clfa_downstream_check(struct isis_spftree *spftree,
+				  struct isis_vertex *vertex_S_D,
+				  struct isis_spf_adj *sadj_N)
+{
+	struct isis_spf_node *node_N;
+	uint32_t dist_N_D;
+	uint32_t dist_S_D;
+
+	node_N = isis_spf_node_find(&spftree->adj_nodes, sadj_N->id);
+	assert(node_N);
+
+	/* Distance from N to D. */
+	if (lfa_calc_dist_destination(node_N->lfa.spftree, vertex_S_D,
+				      &dist_N_D)
+	    != 0)
+		return false;
+
+	/* Distance from S (or PN) to D. */
+	vertex_S_D = listnode_head(vertex_S_D->parents);
+	dist_S_D = vertex_S_D->d_N;
+
+	if (IS_DEBUG_LFA)
+		zlog_debug("ISIS-LFA: downstream check: %u < %u", dist_N_D,
+			   dist_S_D);
+
+	if (dist_N_D < dist_S_D)
+		return true;
+
+	return false;
+}
+
+/*
+ * Check loop-free criterion (RFC 5286's inequality 3):
+ * - Dist_opt(N, D) < Dist_opt(N, E) + Dist_opt(E, D)
+ */
+static bool clfa_node_protecting_check(struct isis_spftree *spftree,
+				       struct isis_vertex *vertex_S_D,
+				       struct isis_spf_adj *sadj_N,
+				       struct isis_spf_adj *sadj_E)
+{
+	struct isis_spf_node *node_N, *node_E;
+	uint32_t dist_N_D;
+	uint32_t dist_N_E;
+	uint32_t dist_E_D;
+
+	node_N = isis_spf_node_find(&spftree->adj_nodes, sadj_N->id);
+	assert(node_N);
+	node_E = isis_spf_node_find(&spftree->adj_nodes, sadj_E->id);
+	assert(node_E);
+
+	/* Distance from N to D. */
+	if (lfa_calc_dist_destination(node_N->lfa.spftree, vertex_S_D,
+				      &dist_N_D)
+	    != 0)
+		return false;
+
+	/* Distance from N to E. */
+	if (lfa_calc_dist_node(node_N->lfa.spftree, node_E->sysid, &dist_N_E)
+	    != 0)
+		return false;
+
+	/* Distance from E to D. */
+	if (lfa_calc_dist_destination(node_E->lfa.spftree, vertex_S_D,
+				      &dist_E_D)
+	    != 0)
+		return false;
+
+	if (IS_DEBUG_LFA)
+		zlog_debug("ISIS-LFA: node protecting check: %u < %u + %u",
+			   dist_N_D, dist_N_E, dist_E_D);
+
+	return (dist_N_D < (dist_N_E + dist_E_D));
+}
+
+static struct list *
+isis_lfa_tiebreakers(struct isis_area *area, struct isis_circuit *circuit,
+		     struct isis_spftree *spftree,
+		     struct lfa_protected_resource *resource,
+		     struct isis_vertex *vertex,
+		     struct isis_spf_adj *sadj_primary, struct list *lfa_list)
+{
+	struct lfa_tiebreaker *tie_b;
+	int level = spftree->level;
+	struct list *filtered_lfa_list;
+	struct list *tent_lfa_list;
+
+	filtered_lfa_list = list_dup(lfa_list);
+	filtered_lfa_list->del = NULL;
+
+	if (listcount(filtered_lfa_list) == 1)
+		return filtered_lfa_list;
+
+	/* Check tiebreakers in ascending order by index. */
+	frr_each (lfa_tiebreaker_tree, &area->lfa_tiebreakers[level - 1],
+		  tie_b) {
+		struct isis_vertex_adj *lfa;
+		struct listnode *node, *nnode;
+		uint32_t best_metric = UINT32_MAX;
+
+		tent_lfa_list = list_dup(filtered_lfa_list);
+
+		switch (tie_b->type) {
+		case LFA_TIEBREAKER_DOWNSTREAM:
+			for (ALL_LIST_ELEMENTS(tent_lfa_list, node, nnode,
+					       lfa)) {
+				if (clfa_downstream_check(spftree, vertex,
+							  lfa->sadj))
+					continue;
+
+				if (IS_DEBUG_LFA)
+					zlog_debug(
+						"ISIS-LFA: LFA %s doesn't satisfy the downstream condition",
+						print_sys_hostname(
+							lfa->sadj->id));
+				listnode_delete(tent_lfa_list, lfa);
+			}
+			break;
+		case LFA_TIEBREAKER_LOWEST_METRIC:
+			/* Find the best metric first. */
+			for (ALL_LIST_ELEMENTS_RO(tent_lfa_list, node, lfa)) {
+				if (lfa->lfa_metric < best_metric)
+					best_metric = lfa->lfa_metric;
+			}
+
+			/* Remove LFAs that don't have the best metric. */
+			for (ALL_LIST_ELEMENTS(tent_lfa_list, node, nnode,
+					       lfa)) {
+				if (lfa->lfa_metric == best_metric)
+					continue;
+
+				if (IS_DEBUG_LFA)
+					zlog_debug(
+						"ISIS-LFA: LFA %s doesn't have the lowest cost metric",
+						print_sys_hostname(
+							lfa->sadj->id));
+				listnode_delete(tent_lfa_list, lfa);
+			}
+			break;
+		case LFA_TIEBREAKER_NODE_PROTECTING:
+			for (ALL_LIST_ELEMENTS(tent_lfa_list, node, nnode,
+					       lfa)) {
+				if (clfa_node_protecting_check(spftree, vertex,
+							       lfa->sadj,
+							       sadj_primary))
+					continue;
+
+				if (IS_DEBUG_LFA)
+					zlog_debug(
+						"ISIS-LFA: LFA %s doesn't provide node protection",
+						print_sys_hostname(
+							lfa->sadj->id));
+				listnode_delete(tent_lfa_list, lfa);
+			}
+			break;
+		}
+
+		/*
+		 * Decide what to do next based on the number of remaining LFAs.
+		 */
+		switch (listcount(tent_lfa_list)) {
+		case 0:
+			/*
+			 * Ignore this tie-breaker since it excluded all LFAs.
+			 * Move on to the next one (if any).
+			 */
+			list_delete(&tent_lfa_list);
+			break;
+		case 1:
+			/* Finish tie-breaking once we get a single LFA. */
+			list_delete(&filtered_lfa_list);
+			filtered_lfa_list = tent_lfa_list;
+			return filtered_lfa_list;
+		default:
+			/*
+			 * We still have two or more LFAs. Move on to the next
+			 * tie-breaker (if any).
+			 */
+			list_delete(&filtered_lfa_list);
+			filtered_lfa_list = tent_lfa_list;
+			break;
+		}
+	}
+
+	return filtered_lfa_list;
+}
+
+void isis_lfa_compute(struct isis_area *area, struct isis_circuit *circuit,
+		      struct isis_spftree *spftree,
+		      struct lfa_protected_resource *resource)
+{
+	struct isis_vertex *vertex;
+	struct listnode *vnode, *snode;
+	int level = spftree->level;
+
+	resource->type = LFA_LINK_PROTECTION;
+
+	for (ALL_QUEUE_ELEMENTS_RO(&spftree->paths, vnode, vertex)) {
+		struct list *lfa_list;
+		struct list *filtered_lfa_list;
+		struct isis_spf_adj *sadj_N;
+		struct isis_vertex_adj *vadj_primary;
+		struct isis_spf_adj *sadj_primary;
+		bool allow_ecmp;
+		uint32_t best_metric = UINT32_MAX;
+		char buf[VID2STR_BUFFER];
+
+		if (!VTYPE_IP(vertex->type))
+			continue;
+
+		vid2string(vertex, buf, sizeof(buf));
+
+		if (!spf_vertex_check_is_affected(vertex, spftree->sysid,
+						  resource)) {
+			if (IS_DEBUG_LFA)
+				zlog_debug(
+					"ISIS-LFA: route unaffected by %s",
+					lfa_protected_resource2str(resource));
+			continue;
+		}
+
+		if (IS_DEBUG_LFA)
+			zlog_debug("ISIS-LFA: checking %s %s w.r.t %s",
+				   vtype2string(vertex->type), buf,
+				   lfa_protected_resource2str(resource));
+
+		if (vertex->N.ip.priority
+		    > area->lfa_priority_limit[level - 1]) {
+			if (IS_DEBUG_LFA)
+				zlog_debug(
+					"ISIS-LFA: skipping computing LFAs due to low prefix priority");
+			continue;
+		}
+
+		vadj_primary = listnode_head(vertex->Adj_N);
+		sadj_primary = vadj_primary->sadj;
+
+		/*
+		 * Loop over list of SPF adjacencies and compute a list of
+		 * preliminary LFAs.
+		 */
+		lfa_list = list_new();
+		lfa_list->del = isis_vertex_adj_free;
+		for (ALL_LIST_ELEMENTS_RO(spftree->sadj_list, snode, sadj_N)) {
+			uint32_t lfa_metric;
+			struct isis_vertex_adj *lfa;
+			struct isis_prefix_sid *psid = NULL;
+			bool last_hop = false;
+
+			/* Skip pseudonodes. */
+			if (LSP_PSEUDO_ID(sadj_N->id))
+				continue;
+
+			/*
+			 * Skip nexthops that are along a link whose cost is
+			 * infinite.
+			 */
+			if (CHECK_FLAG(sadj_N->flags,
+				       F_ISIS_SPF_ADJ_METRIC_INFINITY))
+				continue;
+
+			/* Skip nexthops that have the overload bit set. */
+			if (spftree->mtid != ISIS_MT_IPV4_UNICAST) {
+				struct isis_mt_router_info *mt_router_info;
+
+				mt_router_info =
+					isis_tlvs_lookup_mt_router_info(
+						sadj_N->lsp->tlvs,
+						spftree->mtid);
+				if (mt_router_info && mt_router_info->overload)
+					continue;
+			} else if (ISIS_MASK_LSP_OL_BIT(
+					   sadj_N->lsp->hdr.lsp_bits))
+				continue;
+
+			/* Skip primary nexthop. */
+			if (spf_adj_check_is_affected(sadj_N, resource, NULL,
+						      false))
+				continue;
+
+			/* Skip excluded interfaces as per the configuration. */
+			if (circuit
+			    && isis_lfa_excluded_iface_check(
+				       circuit, level,
+				       sadj_N->adj->circuit->interface->name))
+				continue;
+
+			if (IS_DEBUG_LFA)
+				zlog_debug(
+					"ISIS-LFA: checking candidate LFA %s",
+					print_sys_hostname(sadj_N->id));
+
+			/* Check loop-free criterion. */
+			if (!clfa_loop_free_check(spftree, vertex, sadj_primary,
+						  sadj_N, &lfa_metric)) {
+				if (IS_DEBUG_LFA)
+					zlog_debug(
+						"ISIS-LFA: LFA condition not met for %s",
+						print_sys_hostname(sadj_N->id));
+				continue;
+			}
+
+			if (lfa_metric < best_metric)
+				best_metric = lfa_metric;
+
+			if (IS_DEBUG_LFA)
+				zlog_debug(
+					"ISIS-LFA: %s is a valid loop-free alternate",
+					print_sys_hostname(sadj_N->id));
+
+			if (vertex->N.ip.sr.present) {
+				psid = &vertex->N.ip.sr.sid;
+				if (lfa_metric == sadj_N->metric)
+					last_hop = true;
+			}
+			lfa = isis_vertex_adj_add(spftree, vertex, lfa_list,
+						  sadj_N, psid, last_hop);
+			lfa->lfa_metric = lfa_metric;
+		}
+
+		if (list_isempty(lfa_list)) {
+			if (IS_DEBUG_LFA)
+				zlog_debug("ISIS-LFA: no valid LFAs found");
+			list_delete(&lfa_list);
+			continue;
+		}
+
+		/* Check tie-breakers. */
+		filtered_lfa_list =
+			isis_lfa_tiebreakers(area, circuit, spftree, resource,
+					     vertex, sadj_primary, lfa_list);
+
+		/* Create backup route using the best LFAs. */
+		allow_ecmp = area->lfa_load_sharing[level - 1];
+		isis_route_create(&vertex->N.ip.p.dest, &vertex->N.ip.p.src,
+				  best_metric, vertex->depth, &vertex->N.ip.sr,
+				  filtered_lfa_list, allow_ecmp, area,
+				  spftree->route_table_backup);
+		spftree->lfa.protection_counters.lfa[vertex->N.ip.priority] +=
+			1;
+
+		list_delete(&filtered_lfa_list);
+		list_delete(&lfa_list);
+	}
+}
+
+static void isis_spf_run_tilfa(struct isis_area *area,
+			       struct isis_circuit *circuit,
+			       struct isis_spftree *spftree,
+			       struct isis_spftree *spftree_reverse,
+			       struct lfa_protected_resource *resource)
+{
+	struct isis_spftree *spftree_pc_link;
+	struct isis_spftree *spftree_pc_node;
+
+	/* Compute node protecting repair paths first (if necessary). */
+	if (circuit->tilfa_node_protection[spftree->level - 1]) {
+		resource->type = LFA_NODE_PROTECTION;
+		spftree_pc_node = isis_tilfa_compute(area, spftree,
+						     spftree_reverse, resource);
+		isis_spftree_del(spftree_pc_node);
+	}
+
+	/* Compute link protecting repair paths. */
+	resource->type = LFA_LINK_PROTECTION;
+	spftree_pc_link =
+		isis_tilfa_compute(area, spftree, spftree_reverse, resource);
+	isis_spftree_del(spftree_pc_link);
+}
+
 /**
- * Run the TI-LFA algorithm for all proctected interfaces.
+ * Run the LFA/TI-LFA algorithms for all protected interfaces.
  *
  * @param area		IS-IS area
  * @param spftree	IS-IS SPF tree
  */
 void isis_spf_run_lfa(struct isis_area *area, struct isis_spftree *spftree)
 {
-	struct isis_spftree *spftree_reverse;
+	struct isis_spftree *spftree_reverse = NULL;
 	struct isis_circuit *circuit;
 	struct listnode *node;
+	bool tilfa_configured;
+	int level = spftree->level;
+
+	tilfa_configured = (area->tilfa_protected_links[level - 1] > 0);
 
 	/* Run reverse SPF locally. */
-	spftree_reverse = isis_spf_reverse_run(spftree);
+	if (tilfa_configured)
+		spftree_reverse = isis_spf_reverse_run(spftree);
 
 	/* Run forward SPF on all adjacent routers. */
 	isis_spf_run_neighbors(spftree);
@@ -1056,20 +1772,19 @@ void isis_spf_run_lfa(struct isis_area *area, struct isis_spftree *spftree)
 	for (ALL_LIST_ELEMENTS_RO(area->circuit_list, node, circuit)) {
 		struct lfa_protected_resource resource = {};
 		struct isis_adjacency *adj;
-		struct isis_spftree *spftree_pc_link;
-		struct isis_spftree *spftree_pc_node;
 		static uint8_t null_sysid[ISIS_SYS_ID_LEN + 1];
 
-		if (!(circuit->is_type & spftree->level))
+		if (!(circuit->is_type & level))
 			continue;
 
-		if (!circuit->tilfa_protection[spftree->level - 1])
+		if (!circuit->lfa_protection[level - 1]
+		    && !circuit->tilfa_protection[level - 1])
 			continue;
 
 		/* Fill in the protected resource. */
 		switch (circuit->circ_type) {
 		case CIRCUIT_T_BROADCAST:
-			if (spftree->level == 1)
+			if (level == ISIS_LEVEL1)
 				memcpy(resource.adjacency,
 				       circuit->u.bc.l1_desig_is,
 				       ISIS_SYS_ID_LEN + 1);
@@ -1093,20 +1808,15 @@ void isis_spf_run_lfa(struct isis_area *area, struct isis_spftree *spftree)
 			continue;
 		}
 
-		/* Compute node protecting repair paths first (if necessary). */
-		if (circuit->tilfa_node_protection[spftree->level - 1]) {
-			resource.type = LFA_NODE_PROTECTION;
-			spftree_pc_node = isis_tilfa_compute(
-				area, spftree, spftree_reverse, &resource);
-			isis_spftree_del(spftree_pc_node);
+		if (circuit->lfa_protection[level - 1])
+			isis_lfa_compute(area, circuit, spftree, &resource);
+		else if (circuit->tilfa_protection[level - 1]) {
+			assert(spftree_reverse);
+			isis_spf_run_tilfa(area, circuit, spftree,
+					   spftree_reverse, &resource);
 		}
-
-		/* Compute link protecting repair paths. */
-		resource.type = LFA_LINK_PROTECTION;
-		spftree_pc_link = isis_tilfa_compute(
-			area, spftree, spftree_reverse, &resource);
-		isis_spftree_del(spftree_pc_link);
 	}
 
-	isis_spftree_del(spftree_reverse);
+	if (tilfa_configured)
+		isis_spftree_del(spftree_reverse);
 }
diff --git a/isisd/isis_lfa.h b/isisd/isis_lfa.h
index 835618760..f09fc663a 100644
--- a/isisd/isis_lfa.h
+++ b/isisd/isis_lfa.h
@@ -20,6 +20,27 @@
 #ifndef _FRR_ISIS_LFA_H
 #define _FRR_ISIS_LFA_H
 
+#include "lib/typesafe.h"
+
+PREDECL_RBTREE_UNIQ(lfa_tiebreaker_tree)
+
+enum lfa_tiebreaker_type {
+	LFA_TIEBREAKER_DOWNSTREAM = 0,
+	LFA_TIEBREAKER_LOWEST_METRIC,
+	LFA_TIEBREAKER_NODE_PROTECTING,
+};
+
+struct lfa_tiebreaker {
+	struct lfa_tiebreaker_tree_item entry;
+	uint8_t index;
+	enum lfa_tiebreaker_type type;
+	struct isis_area *area;
+};
+int lfa_tiebreaker_cmp(const struct lfa_tiebreaker *a,
+		       const struct lfa_tiebreaker *b);
+DECLARE_RBTREE_UNIQ(lfa_tiebreaker_tree, struct lfa_tiebreaker, entry,
+		    lfa_tiebreaker_cmp)
+
 enum isis_tilfa_sid_type {
 	TILFA_SID_PREFIX = 1,
 	TILFA_SID_ADJ,
@@ -37,6 +58,20 @@ struct isis_tilfa_sid {
 	} value;
 };
 
+enum spf_prefix_priority {
+	SPF_PREFIX_PRIO_CRITICAL = 0,
+	SPF_PREFIX_PRIO_HIGH,
+	SPF_PREFIX_PRIO_MEDIUM,
+	SPF_PREFIX_PRIO_LOW,
+	SPF_PREFIX_PRIO_MAX,
+};
+
+struct spf_prefix_priority_acl {
+	char *name;
+	struct access_list *list_v4;
+	struct access_list *list_v6;
+};
+
 RB_HEAD(isis_spf_nodes, isis_spf_node);
 RB_PROTOTYPE(isis_spf_nodes, isis_spf_node, entry, isis_spf_node_compare)
 struct isis_spf_node {
@@ -89,14 +124,32 @@ struct isis_spf_node *isis_spf_node_new(struct isis_spf_nodes *nodes,
 					const uint8_t *sysid);
 struct isis_spf_node *isis_spf_node_find(const struct isis_spf_nodes *nodes,
 					 const uint8_t *sysid);
+void isis_lfa_tiebreakers_init(struct isis_area *area, int level);
+void isis_lfa_tiebreakers_clear(struct isis_area *area, int level);
+struct lfa_tiebreaker *isis_lfa_tiebreaker_add(struct isis_area *area,
+					       int level, uint8_t index,
+					       enum lfa_tiebreaker_type type);
+void isis_lfa_tiebreaker_delete(struct isis_area *area, int level,
+				struct lfa_tiebreaker *tie_b);
+void isis_lfa_excluded_ifaces_init(struct isis_circuit *circuit, int level);
+void isis_lfa_excluded_ifaces_clear(struct isis_circuit *circuit, int level);
+void isis_lfa_excluded_iface_add(struct isis_circuit *circuit, int level,
+				 const char *ifname);
+void isis_lfa_excluded_iface_delete(struct isis_circuit *circuit, int level,
+				    const char *ifname);
+bool isis_lfa_excluded_iface_check(struct isis_circuit *circuit, int level,
+				   const char *ifname);
 bool isis_lfa_excise_adj_check(const struct isis_spftree *spftree,
 			       const uint8_t *id);
 bool isis_lfa_excise_node_check(const struct isis_spftree *spftree,
 				const uint8_t *id);
 struct isis_spftree *isis_spf_reverse_run(const struct isis_spftree *spftree);
 int isis_spf_run_neighbors(struct isis_spftree *spftree);
+void isis_lfa_compute(struct isis_area *area, struct isis_circuit *circuit,
+		      struct isis_spftree *spftree,
+		      struct lfa_protected_resource *resource);
 void isis_spf_run_lfa(struct isis_area *area, struct isis_spftree *spftree);
-int isis_lfa_check(struct isis_spftree *spftree, struct isis_vertex *vertex);
+int isis_tilfa_check(struct isis_spftree *spftree, struct isis_vertex *vertex);
 struct isis_spftree *
 isis_tilfa_compute(struct isis_area *area, struct isis_spftree *spftree,
 		   struct isis_spftree *spftree_reverse,
diff --git a/isisd/isis_main.c b/isisd/isis_main.c
index 22df3ff37..4576a4a95 100644
--- a/isisd/isis_main.c
+++ b/isisd/isis_main.c
@@ -242,6 +242,8 @@ int main(int argc, char **argv, char **envp)
 	 */
 	isis_error_init();
 	access_list_init();
+	access_list_add_hook(isis_filter_update);
+	access_list_delete_hook(isis_filter_update);
 	isis_vrf_init();
 	prefix_list_init();
 	isis_init();
diff --git a/isisd/isis_memory.c b/isisd/isis_memory.c
index a64decc14..b63a82f40 100644
--- a/isisd/isis_memory.c
+++ b/isisd/isis_memory.c
@@ -45,3 +45,4 @@ DEFINE_MTYPE(ISISD, ISIS_DICT_NODE, "ISIS dictionary node")
 DEFINE_MTYPE(ISISD, ISIS_EXT_ROUTE, "ISIS redistributed route")
 DEFINE_MTYPE(ISISD, ISIS_EXT_INFO, "ISIS redistributed route info")
 DEFINE_MTYPE(ISISD, ISIS_MPLS_TE, "ISIS MPLS_TE parameters")
+DEFINE_MTYPE(ISISD, ISIS_ACL_NAME, "ISIS access-list name")
diff --git a/isisd/isis_memory.h b/isisd/isis_memory.h
index 6b63b3ccb..3ef1c5bf0 100644
--- a/isisd/isis_memory.h
+++ b/isisd/isis_memory.h
@@ -44,5 +44,6 @@ DECLARE_MTYPE(ISIS_DICT_NODE)
 DECLARE_MTYPE(ISIS_EXT_ROUTE)
 DECLARE_MTYPE(ISIS_EXT_INFO)
 DECLARE_MTYPE(ISIS_MPLS_TE)
+DECLARE_MTYPE(ISIS_ACL_NAME)
 
 #endif /* _QUAGGA_ISIS_MEMORY_H */
diff --git a/isisd/isis_nb.c b/isisd/isis_nb.c
index 2d3c7e1e3..c3d2f238d 100644
--- a/isisd/isis_nb.c
+++ b/isisd/isis_nb.c
@@ -194,6 +194,30 @@ const struct frr_yang_module_info frr_isisd_info = {
 			},
 		},
 		{
+			.xpath = "/frr-isisd:isis/instance/spf/prefix-priorities/critical/access-list-name",
+			.cbs = {
+				.cli_show = cli_show_isis_spf_prefix_priority,
+				.modify = isis_instance_spf_prefix_priorities_critical_access_list_name_modify,
+				.destroy = isis_instance_spf_prefix_priorities_critical_access_list_name_destroy,
+			}
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/spf/prefix-priorities/high/access-list-name",
+			.cbs = {
+				.cli_show = cli_show_isis_spf_prefix_priority,
+				.modify = isis_instance_spf_prefix_priorities_high_access_list_name_modify,
+				.destroy = isis_instance_spf_prefix_priorities_high_access_list_name_destroy,
+			}
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/spf/prefix-priorities/medium/access-list-name",
+			.cbs = {
+				.cli_show = cli_show_isis_spf_prefix_priority,
+				.modify = isis_instance_spf_prefix_priorities_medium_access_list_name_modify,
+				.destroy = isis_instance_spf_prefix_priorities_medium_access_list_name_destroy,
+			}
+		},
+		{
 			.xpath = "/frr-isisd:isis/instance/area-password",
 			.cbs = {
 				.apply_finish = area_password_apply_finish,
@@ -432,6 +456,64 @@ const struct frr_yang_module_info frr_isisd_info = {
 			},
 		},
 		{
+			.xpath = "/frr-isisd:isis/instance/fast-reroute/level-1/lfa/load-sharing",
+			.cbs = {
+				.cli_show = cli_show_isis_frr_lfa_load_sharing,
+				.modify = isis_instance_fast_reroute_level_1_lfa_load_sharing_modify,
+			}
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/fast-reroute/level-1/lfa/priority-limit",
+			.cbs = {
+				.cli_show = cli_show_isis_frr_lfa_priority_limit,
+				.modify = isis_instance_fast_reroute_level_1_lfa_priority_limit_modify,
+				.destroy = isis_instance_fast_reroute_level_1_lfa_priority_limit_destroy,
+			}
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/fast-reroute/level-1/lfa/tiebreaker",
+			.cbs = {
+				.cli_show = cli_show_isis_frr_lfa_tiebreaker,
+				.create = isis_instance_fast_reroute_level_1_lfa_tiebreaker_create,
+				.destroy = isis_instance_fast_reroute_level_1_lfa_tiebreaker_destroy,
+			}
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/fast-reroute/level-1/lfa/tiebreaker/type",
+			.cbs = {
+				.modify = isis_instance_fast_reroute_level_1_lfa_tiebreaker_type_modify,
+			}
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/fast-reroute/level-2/lfa/load-sharing",
+			.cbs = {
+				.cli_show = cli_show_isis_frr_lfa_load_sharing,
+				.modify = isis_instance_fast_reroute_level_2_lfa_load_sharing_modify,
+			}
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/fast-reroute/level-2/lfa/priority-limit",
+			.cbs = {
+				.cli_show = cli_show_isis_frr_lfa_priority_limit,
+				.modify = isis_instance_fast_reroute_level_2_lfa_priority_limit_modify,
+				.destroy = isis_instance_fast_reroute_level_2_lfa_priority_limit_destroy,
+			}
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/fast-reroute/level-2/lfa/tiebreaker",
+			.cbs = {
+				.cli_show = cli_show_isis_frr_lfa_tiebreaker,
+				.create = isis_instance_fast_reroute_level_2_lfa_tiebreaker_create,
+				.destroy = isis_instance_fast_reroute_level_2_lfa_tiebreaker_destroy,
+			}
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/fast-reroute/level-2/lfa/tiebreaker/type",
+			.cbs = {
+				.modify = isis_instance_fast_reroute_level_2_lfa_tiebreaker_type_modify,
+			}
+		},
+		{
 			.xpath = "/frr-isisd:isis/instance/log-adjacency-changes",
 			.cbs = {
 				.cli_show = cli_show_isis_log_adjacency,
@@ -827,7 +909,21 @@ const struct frr_yang_module_info frr_isisd_info = {
 		{
 			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/fast-reroute",
 			.cbs = {
-				.cli_show = cli_show_ip_isis_ti_lfa,
+				.cli_show = cli_show_ip_isis_frr,
+			}
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/fast-reroute/level-1/lfa/enable",
+			.cbs = {
+				.modify = lib_interface_isis_fast_reroute_level_1_lfa_enable_modify,
+			}
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/fast-reroute/level-1/lfa/exclude-interface",
+			.cbs = {
+				.cli_show = cli_show_frr_lfa_exclude_interface,
+				.create = lib_interface_isis_fast_reroute_level_1_lfa_exclude_interface_create,
+				.destroy = lib_interface_isis_fast_reroute_level_1_lfa_exclude_interface_destroy,
 			}
 		},
 		{
@@ -843,6 +939,20 @@ const struct frr_yang_module_info frr_isisd_info = {
 			}
 		},
 		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/fast-reroute/level-2/lfa/enable",
+			.cbs = {
+				.modify = lib_interface_isis_fast_reroute_level_2_lfa_enable_modify,
+			}
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/fast-reroute/level-2/lfa/exclude-interface",
+			.cbs = {
+				.cli_show = cli_show_frr_lfa_exclude_interface,
+				.create = lib_interface_isis_fast_reroute_level_2_lfa_exclude_interface_create,
+				.destroy = lib_interface_isis_fast_reroute_level_2_lfa_exclude_interface_destroy,
+			}
+		},
+		{
 			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/fast-reroute/level-2/ti-lfa/enable",
 			.cbs = {
 				.modify = lib_interface_isis_fast_reroute_level_2_ti_lfa_enable_modify,
diff --git a/isisd/isis_nb.h b/isisd/isis_nb.h
index fb843131d..f529f2086 100644
--- a/isisd/isis_nb.h
+++ b/isisd/isis_nb.h
@@ -68,6 +68,18 @@ int isis_instance_spf_minimum_interval_level_1_modify(
 	struct nb_cb_modify_args *args);
 int isis_instance_spf_minimum_interval_level_2_modify(
 	struct nb_cb_modify_args *args);
+int isis_instance_spf_prefix_priorities_critical_access_list_name_modify(
+	struct nb_cb_modify_args *args);
+int isis_instance_spf_prefix_priorities_critical_access_list_name_destroy(
+	struct nb_cb_destroy_args *args);
+int isis_instance_spf_prefix_priorities_high_access_list_name_modify(
+	struct nb_cb_modify_args *args);
+int isis_instance_spf_prefix_priorities_high_access_list_name_destroy(
+	struct nb_cb_destroy_args *args);
+int isis_instance_spf_prefix_priorities_medium_access_list_name_modify(
+	struct nb_cb_modify_args *args);
+int isis_instance_spf_prefix_priorities_medium_access_list_name_destroy(
+	struct nb_cb_destroy_args *args);
 int isis_instance_area_password_create(struct nb_cb_create_args *args);
 int isis_instance_area_password_destroy(struct nb_cb_destroy_args *args);
 int isis_instance_area_password_password_modify(struct nb_cb_modify_args *args);
@@ -159,6 +171,30 @@ int isis_instance_multi_topology_ipv6_dstsrc_destroy(
 	struct nb_cb_destroy_args *args);
 int isis_instance_multi_topology_ipv6_dstsrc_overload_modify(
 	struct nb_cb_modify_args *args);
+int isis_instance_fast_reroute_level_1_lfa_load_sharing_modify(
+	struct nb_cb_modify_args *args);
+int isis_instance_fast_reroute_level_1_lfa_priority_limit_modify(
+	struct nb_cb_modify_args *args);
+int isis_instance_fast_reroute_level_1_lfa_priority_limit_destroy(
+	struct nb_cb_destroy_args *args);
+int isis_instance_fast_reroute_level_1_lfa_tiebreaker_create(
+	struct nb_cb_create_args *args);
+int isis_instance_fast_reroute_level_1_lfa_tiebreaker_destroy(
+	struct nb_cb_destroy_args *args);
+int isis_instance_fast_reroute_level_1_lfa_tiebreaker_type_modify(
+	struct nb_cb_modify_args *args);
+int isis_instance_fast_reroute_level_2_lfa_load_sharing_modify(
+	struct nb_cb_modify_args *args);
+int isis_instance_fast_reroute_level_2_lfa_priority_limit_modify(
+	struct nb_cb_modify_args *args);
+int isis_instance_fast_reroute_level_2_lfa_priority_limit_destroy(
+	struct nb_cb_destroy_args *args);
+int isis_instance_fast_reroute_level_2_lfa_tiebreaker_create(
+	struct nb_cb_create_args *args);
+int isis_instance_fast_reroute_level_2_lfa_tiebreaker_destroy(
+	struct nb_cb_destroy_args *args);
+int isis_instance_fast_reroute_level_2_lfa_tiebreaker_type_modify(
+	struct nb_cb_modify_args *args);
 int isis_instance_log_adjacency_changes_modify(struct nb_cb_modify_args *args);
 int isis_instance_mpls_te_create(struct nb_cb_create_args *args);
 int isis_instance_mpls_te_destroy(struct nb_cb_destroy_args *args);
@@ -258,10 +294,22 @@ int lib_interface_isis_multi_topology_ipv6_dstsrc_modify(
 int lib_interface_isis_mpls_ldp_sync_modify(struct nb_cb_modify_args *args);
 int lib_interface_isis_mpls_holddown_modify(struct nb_cb_modify_args *args);
 int lib_interface_isis_mpls_holddown_destroy(struct nb_cb_destroy_args *args);
+int lib_interface_isis_fast_reroute_level_1_lfa_enable_modify(
+	struct nb_cb_modify_args *args);
+int lib_interface_isis_fast_reroute_level_1_lfa_exclude_interface_create(
+	struct nb_cb_create_args *args);
+int lib_interface_isis_fast_reroute_level_1_lfa_exclude_interface_destroy(
+	struct nb_cb_destroy_args *args);
 int lib_interface_isis_fast_reroute_level_1_ti_lfa_enable_modify(
 	struct nb_cb_modify_args *args);
 int lib_interface_isis_fast_reroute_level_1_ti_lfa_node_protection_modify(
 	struct nb_cb_modify_args *args);
+int lib_interface_isis_fast_reroute_level_2_lfa_enable_modify(
+	struct nb_cb_modify_args *args);
+int lib_interface_isis_fast_reroute_level_2_lfa_exclude_interface_create(
+	struct nb_cb_create_args *args);
+int lib_interface_isis_fast_reroute_level_2_lfa_exclude_interface_destroy(
+	struct nb_cb_destroy_args *args);
 int lib_interface_isis_fast_reroute_level_2_ti_lfa_enable_modify(
 	struct nb_cb_modify_args *args);
 int lib_interface_isis_fast_reroute_level_2_ti_lfa_node_protection_modify(
@@ -374,6 +422,8 @@ void cli_show_isis_spf_min_interval(struct vty *vty, struct lyd_node *dnode,
 				    bool show_defaults);
 void cli_show_isis_spf_ietf_backoff(struct vty *vty, struct lyd_node *dnode,
 				    bool show_defaults);
+void cli_show_isis_spf_prefix_priority(struct vty *vty, struct lyd_node *dnode,
+				       bool show_defaults);
 void cli_show_isis_purge_origin(struct vty *vty, struct lyd_node *dnode,
 				bool show_defaults);
 void cli_show_isis_mpls_te(struct vty *vty, struct lyd_node *dnode,
@@ -410,6 +460,13 @@ void cli_show_isis_node_msd(struct vty *vty, struct lyd_node *dnode,
 			    bool show_defaults);
 void cli_show_isis_prefix_sid(struct vty *vty, struct lyd_node *dnode,
 			      bool show_defaults);
+void cli_show_isis_frr_lfa_priority_limit(struct vty *vty,
+					  struct lyd_node *dnode,
+					  bool show_defaults);
+void cli_show_isis_frr_lfa_tiebreaker(struct vty *vty, struct lyd_node *dnode,
+				      bool show_defaults);
+void cli_show_isis_frr_lfa_load_sharing(struct vty *vty, struct lyd_node *dnode,
+					bool show_defaults);
 void cli_show_ip_isis_passive(struct vty *vty, struct lyd_node *dnode,
 			      bool show_defaults);
 void cli_show_ip_isis_password(struct vty *vty, struct lyd_node *dnode,
@@ -442,8 +499,10 @@ void cli_show_ip_isis_mt_ipv6_mgmt(struct vty *vty, struct lyd_node *dnode,
 				   bool show_defaults);
 void cli_show_ip_isis_mt_ipv6_dstsrc(struct vty *vty, struct lyd_node *dnode,
 				     bool show_defaults);
-void cli_show_ip_isis_ti_lfa(struct vty *vty, struct lyd_node *dnode,
-			     bool show_defaults);
+void cli_show_ip_isis_frr(struct vty *vty, struct lyd_node *dnode,
+			  bool show_defaults);
+void cli_show_frr_lfa_exclude_interface(struct vty *vty, struct lyd_node *dnode,
+					bool show_defaults);
 void cli_show_ip_isis_circ_type(struct vty *vty, struct lyd_node *dnode,
 				bool show_defaults);
 void cli_show_ip_isis_network_type(struct vty *vty, struct lyd_node *dnode,
diff --git a/isisd/isis_nb_config.c b/isisd/isis_nb_config.c
index 45089410e..c12ee44a9 100644
--- a/isisd/isis_nb_config.c
+++ b/isisd/isis_nb_config.c
@@ -27,6 +27,7 @@
 #include "linklist.h"
 #include "log.h"
 #include "bfd.h"
+#include "filter.h"
 #include "spf_backoff.h"
 #include "lib_errors.h"
 #include "vrf.h"
@@ -626,6 +627,145 @@ int isis_instance_spf_minimum_interval_level_2_modify(
 }
 
 /*
+ * XPath:
+ * /frr-isisd:isis/instance/spf/prefix-priorities/critical/access-list-name
+ */
+int isis_instance_spf_prefix_priorities_critical_access_list_name_modify(
+	struct nb_cb_modify_args *args)
+{
+	struct isis_area *area;
+	const char *acl_name;
+	struct spf_prefix_priority_acl *ppa;
+
+	if (args->event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_get_entry(args->dnode, NULL, true);
+	acl_name = yang_dnode_get_string(args->dnode, NULL);
+
+	ppa = &area->spf_prefix_priorities[SPF_PREFIX_PRIO_CRITICAL];
+	XFREE(MTYPE_ISIS_ACL_NAME, ppa->name);
+	ppa->name = XSTRDUP(MTYPE_ISIS_ACL_NAME, acl_name);
+	ppa->list_v4 = access_list_lookup(AFI_IP, acl_name);
+	ppa->list_v6 = access_list_lookup(AFI_IP6, acl_name);
+	lsp_regenerate_schedule(area, area->is_type, 0);
+
+	return NB_OK;
+}
+
+int isis_instance_spf_prefix_priorities_critical_access_list_name_destroy(
+	struct nb_cb_destroy_args *args)
+{
+	struct isis_area *area;
+	struct spf_prefix_priority_acl *ppa;
+
+	if (args->event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_get_entry(args->dnode, NULL, true);
+
+	ppa = &area->spf_prefix_priorities[SPF_PREFIX_PRIO_CRITICAL];
+	XFREE(MTYPE_ISIS_ACL_NAME, ppa->name);
+	ppa->list_v4 = NULL;
+	ppa->list_v6 = NULL;
+	lsp_regenerate_schedule(area, area->is_type, 0);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/spf/prefix-priorities/high/access-list-name
+ */
+int isis_instance_spf_prefix_priorities_high_access_list_name_modify(
+	struct nb_cb_modify_args *args)
+{
+	struct isis_area *area;
+	const char *acl_name;
+	struct spf_prefix_priority_acl *ppa;
+
+	if (args->event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_get_entry(args->dnode, NULL, true);
+	acl_name = yang_dnode_get_string(args->dnode, NULL);
+
+	ppa = &area->spf_prefix_priorities[SPF_PREFIX_PRIO_HIGH];
+	XFREE(MTYPE_ISIS_ACL_NAME, ppa->name);
+	ppa->name = XSTRDUP(MTYPE_ISIS_ACL_NAME, acl_name);
+	ppa->list_v4 = access_list_lookup(AFI_IP, acl_name);
+	ppa->list_v6 = access_list_lookup(AFI_IP6, acl_name);
+	lsp_regenerate_schedule(area, area->is_type, 0);
+
+	return NB_OK;
+}
+
+int isis_instance_spf_prefix_priorities_high_access_list_name_destroy(
+	struct nb_cb_destroy_args *args)
+{
+	struct isis_area *area;
+	struct spf_prefix_priority_acl *ppa;
+
+	if (args->event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_get_entry(args->dnode, NULL, true);
+
+	ppa = &area->spf_prefix_priorities[SPF_PREFIX_PRIO_HIGH];
+	XFREE(MTYPE_ISIS_ACL_NAME, ppa->name);
+	ppa->list_v4 = NULL;
+	ppa->list_v6 = NULL;
+	lsp_regenerate_schedule(area, area->is_type, 0);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/spf/prefix-priorities/medium/access-list-name
+ */
+int isis_instance_spf_prefix_priorities_medium_access_list_name_modify(
+	struct nb_cb_modify_args *args)
+{
+	struct isis_area *area;
+	const char *acl_name;
+	struct spf_prefix_priority_acl *ppa;
+
+	if (args->event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_get_entry(args->dnode, NULL, true);
+	acl_name = yang_dnode_get_string(args->dnode, NULL);
+
+	ppa = &area->spf_prefix_priorities[SPF_PREFIX_PRIO_MEDIUM];
+	XFREE(MTYPE_ISIS_ACL_NAME, ppa->name);
+	ppa->name = XSTRDUP(MTYPE_ISIS_ACL_NAME, acl_name);
+	ppa->list_v4 = access_list_lookup(AFI_IP, acl_name);
+	ppa->list_v6 = access_list_lookup(AFI_IP6, acl_name);
+	lsp_regenerate_schedule(area, area->is_type, 0);
+
+	return NB_OK;
+}
+
+int isis_instance_spf_prefix_priorities_medium_access_list_name_destroy(
+	struct nb_cb_destroy_args *args)
+{
+	struct isis_area *area;
+	struct spf_prefix_priority_acl *ppa;
+
+	if (args->event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_get_entry(args->dnode, NULL, true);
+
+	ppa = &area->spf_prefix_priorities[SPF_PREFIX_PRIO_MEDIUM];
+	XFREE(MTYPE_ISIS_ACL_NAME, ppa->name);
+	ppa->list_v4 = NULL;
+	ppa->list_v6 = NULL;
+	lsp_regenerate_schedule(area, area->is_type, 0);
+
+	return NB_OK;
+}
+
+/*
  * XPath: /frr-isisd:isis/instance/area-password
  */
 void area_password_apply_finish(struct nb_cb_apply_finish_args *args)
@@ -1290,6 +1430,229 @@ int isis_instance_multi_topology_ipv6_dstsrc_overload_modify(
 }
 
 /*
+ * XPath: /frr-isisd:isis/instance/fast-reroute/level-1/lfa/load-sharing
+ */
+int isis_instance_fast_reroute_level_1_lfa_load_sharing_modify(
+	struct nb_cb_modify_args *args)
+{
+	struct isis_area *area;
+
+	if (args->event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_get_entry(args->dnode, NULL, true);
+	area->lfa_load_sharing[0] = yang_dnode_get_bool(args->dnode, NULL);
+	lsp_regenerate_schedule(area, area->is_type, 0);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/fast-reroute/level-1/lfa/priority-limit
+ */
+int isis_instance_fast_reroute_level_1_lfa_priority_limit_modify(
+	struct nb_cb_modify_args *args)
+{
+	struct isis_area *area;
+
+	if (args->event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_get_entry(args->dnode, NULL, true);
+	area->lfa_priority_limit[0] = yang_dnode_get_enum(args->dnode, NULL);
+	lsp_regenerate_schedule(area, area->is_type, 0);
+
+	return NB_OK;
+}
+
+int isis_instance_fast_reroute_level_1_lfa_priority_limit_destroy(
+	struct nb_cb_destroy_args *args)
+{
+	struct isis_area *area;
+
+	if (args->event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_get_entry(args->dnode, NULL, true);
+	area->lfa_priority_limit[0] = SPF_PREFIX_PRIO_LOW;
+	lsp_regenerate_schedule(area, area->is_type, 0);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/fast-reroute/level-1/lfa/tiebreaker
+ */
+int isis_instance_fast_reroute_level_1_lfa_tiebreaker_create(
+	struct nb_cb_create_args *args)
+{
+	struct isis_area *area;
+	uint8_t index;
+	enum lfa_tiebreaker_type type;
+	struct lfa_tiebreaker *tie_b;
+
+	if (args->event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_get_entry(args->dnode, NULL, true);
+	index = yang_dnode_get_uint8(args->dnode, "./index");
+	type = yang_dnode_get_enum(args->dnode, "./type");
+
+	tie_b = isis_lfa_tiebreaker_add(area, ISIS_LEVEL1, index, type);
+	nb_running_set_entry(args->dnode, tie_b);
+	lsp_regenerate_schedule(area, area->is_type, 0);
+
+	return NB_OK;
+}
+
+int isis_instance_fast_reroute_level_1_lfa_tiebreaker_destroy(
+	struct nb_cb_destroy_args *args)
+{
+	struct lfa_tiebreaker *tie_b;
+	struct isis_area *area;
+
+	if (args->event != NB_EV_APPLY)
+		return NB_OK;
+
+	tie_b = nb_running_unset_entry(args->dnode);
+	area = tie_b->area;
+	isis_lfa_tiebreaker_delete(area, ISIS_LEVEL1, tie_b);
+	lsp_regenerate_schedule(area, area->is_type, 0);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/fast-reroute/level-1/lfa/tiebreaker/type
+ */
+int isis_instance_fast_reroute_level_1_lfa_tiebreaker_type_modify(
+	struct nb_cb_modify_args *args)
+{
+	struct lfa_tiebreaker *tie_b;
+	struct isis_area *area;
+
+	if (args->event != NB_EV_APPLY)
+		return NB_OK;
+
+	tie_b = nb_running_get_entry(args->dnode, NULL, true);
+	area = tie_b->area;
+	tie_b->type = yang_dnode_get_enum(args->dnode, NULL);
+	lsp_regenerate_schedule(area, area->is_type, 0);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/fast-reroute/level-2/lfa/load-sharing
+ */
+int isis_instance_fast_reroute_level_2_lfa_load_sharing_modify(
+	struct nb_cb_modify_args *args)
+{
+	struct isis_area *area;
+
+	if (args->event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_get_entry(args->dnode, NULL, true);
+	area->lfa_load_sharing[1] = yang_dnode_get_bool(args->dnode, NULL);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/fast-reroute/level-2/lfa/priority-limit
+ */
+int isis_instance_fast_reroute_level_2_lfa_priority_limit_modify(
+	struct nb_cb_modify_args *args)
+{
+	struct isis_area *area;
+
+	if (args->event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_get_entry(args->dnode, NULL, true);
+	area->lfa_priority_limit[1] = yang_dnode_get_enum(args->dnode, NULL);
+
+	return NB_OK;
+}
+
+int isis_instance_fast_reroute_level_2_lfa_priority_limit_destroy(
+	struct nb_cb_destroy_args *args)
+{
+	struct isis_area *area;
+
+	if (args->event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_get_entry(args->dnode, NULL, true);
+	area->lfa_priority_limit[1] = SPF_PREFIX_PRIO_LOW;
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/fast-reroute/level-2/lfa/tiebreaker
+ */
+int isis_instance_fast_reroute_level_2_lfa_tiebreaker_create(
+	struct nb_cb_create_args *args)
+{
+	struct isis_area *area;
+	uint8_t index;
+	enum lfa_tiebreaker_type type;
+	struct lfa_tiebreaker *tie_b;
+
+	if (args->event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_get_entry(args->dnode, NULL, true);
+	index = yang_dnode_get_uint8(args->dnode, "./index");
+	type = yang_dnode_get_enum(args->dnode, "./type");
+
+	tie_b = isis_lfa_tiebreaker_add(area, ISIS_LEVEL2, index, type);
+	nb_running_set_entry(args->dnode, tie_b);
+	lsp_regenerate_schedule(area, area->is_type, 0);
+
+	return NB_OK;
+}
+
+int isis_instance_fast_reroute_level_2_lfa_tiebreaker_destroy(
+	struct nb_cb_destroy_args *args)
+{
+	struct lfa_tiebreaker *tie_b;
+	struct isis_area *area;
+
+	if (args->event != NB_EV_APPLY)
+		return NB_OK;
+
+	tie_b = nb_running_unset_entry(args->dnode);
+	area = tie_b->area;
+	isis_lfa_tiebreaker_delete(area, ISIS_LEVEL2, tie_b);
+	lsp_regenerate_schedule(area, area->is_type, 0);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/fast-reroute/level-2/lfa/tiebreaker/type
+ */
+int isis_instance_fast_reroute_level_2_lfa_tiebreaker_type_modify(
+	struct nb_cb_modify_args *args)
+{
+	struct lfa_tiebreaker *tie_b;
+	struct isis_area *area;
+
+	if (args->event != NB_EV_APPLY)
+		return NB_OK;
+
+	tie_b = nb_running_get_entry(args->dnode, NULL, true);
+	area = tie_b->area;
+	tie_b->type = yang_dnode_get_enum(args->dnode, NULL);
+	lsp_regenerate_schedule(area, area->is_type, 0);
+
+	return NB_OK;
+}
+
+/*
  * XPath: /frr-isisd:isis/instance/log-adjacency-changes
  */
 int isis_instance_log_adjacency_changes_modify(struct nb_cb_modify_args *args)
@@ -3005,6 +3368,78 @@ int lib_interface_isis_mpls_holddown_destroy(struct nb_cb_destroy_args *args)
 
 /*
  * XPath:
+ * /frr-interface:lib/interface/frr-isisd:isis/fast-reroute/level-1/lfa/enable
+ */
+int lib_interface_isis_fast_reroute_level_1_lfa_enable_modify(
+	struct nb_cb_modify_args *args)
+{
+	struct isis_area *area;
+	struct isis_circuit *circuit;
+
+	if (args->event != NB_EV_APPLY)
+		return NB_OK;
+
+	circuit = nb_running_get_entry(args->dnode, NULL, true);
+	circuit->lfa_protection[0] = yang_dnode_get_bool(args->dnode, NULL);
+	if (circuit->lfa_protection[0])
+		circuit->area->lfa_protected_links[0]++;
+	else {
+		assert(circuit->area->lfa_protected_links[0] > 0);
+		circuit->area->lfa_protected_links[0]--;
+	}
+
+	area = circuit->area;
+	lsp_regenerate_schedule(area, area->is_type, 0);
+
+	return NB_OK;
+}
+
+/*
+ * XPath:
+ * /frr-interface:lib/interface/frr-isisd:isis/fast-reroute/level-1/lfa/exclude-interface
+ */
+int lib_interface_isis_fast_reroute_level_1_lfa_exclude_interface_create(
+	struct nb_cb_create_args *args)
+{
+	struct isis_area *area;
+	struct isis_circuit *circuit;
+	const char *exclude_ifname;
+
+	if (args->event != NB_EV_APPLY)
+		return NB_OK;
+
+	circuit = nb_running_get_entry(args->dnode, NULL, true);
+	exclude_ifname = yang_dnode_get_string(args->dnode, NULL);
+
+	isis_lfa_excluded_iface_add(circuit, ISIS_LEVEL1, exclude_ifname);
+	area = circuit->area;
+	lsp_regenerate_schedule(area, area->is_type, 0);
+
+	return NB_OK;
+}
+
+int lib_interface_isis_fast_reroute_level_1_lfa_exclude_interface_destroy(
+	struct nb_cb_destroy_args *args)
+{
+	struct isis_area *area;
+	struct isis_circuit *circuit;
+	const char *exclude_ifname;
+
+	if (args->event != NB_EV_APPLY)
+		return NB_OK;
+
+	circuit = nb_running_get_entry(args->dnode, NULL, true);
+	exclude_ifname = yang_dnode_get_string(args->dnode, NULL);
+
+	isis_lfa_excluded_iface_delete(circuit, ISIS_LEVEL1, exclude_ifname);
+	area = circuit->area;
+	lsp_regenerate_schedule(area, area->is_type, 0);
+
+	return NB_OK;
+}
+
+/*
+ * XPath:
  * /frr-interface:lib/interface/frr-isisd:isis/fast-reroute/level-1/ti-lfa/enable
  */
 int lib_interface_isis_fast_reroute_level_1_ti_lfa_enable_modify(
@@ -3019,10 +3454,10 @@ int lib_interface_isis_fast_reroute_level_1_ti_lfa_enable_modify(
 	circuit = nb_running_get_entry(args->dnode, NULL, true);
 	circuit->tilfa_protection[0] = yang_dnode_get_bool(args->dnode, NULL);
 	if (circuit->tilfa_protection[0])
-		circuit->area->lfa_protected_links[0]++;
+		circuit->area->tilfa_protected_links[0]++;
 	else {
-		assert(circuit->area->lfa_protected_links[0] > 0);
-		circuit->area->lfa_protected_links[0]--;
+		assert(circuit->area->tilfa_protected_links[0] > 0);
+		circuit->area->tilfa_protected_links[0]--;
 	}
 
 	area = circuit->area;
@@ -3056,6 +3491,78 @@ int lib_interface_isis_fast_reroute_level_1_ti_lfa_node_protection_modify(
 
 /*
  * XPath:
+ * /frr-interface:lib/interface/frr-isisd:isis/fast-reroute/level-2/lfa/enable
+ */
+int lib_interface_isis_fast_reroute_level_2_lfa_enable_modify(
+	struct nb_cb_modify_args *args)
+{
+	struct isis_area *area;
+	struct isis_circuit *circuit;
+
+	if (args->event != NB_EV_APPLY)
+		return NB_OK;
+
+	circuit = nb_running_get_entry(args->dnode, NULL, true);
+	circuit->lfa_protection[1] = yang_dnode_get_bool(args->dnode, NULL);
+	if (circuit->lfa_protection[1])
+		circuit->area->lfa_protected_links[1]++;
+	else {
+		assert(circuit->area->lfa_protected_links[1] > 0);
+		circuit->area->lfa_protected_links[1]--;
+	}
+
+	area = circuit->area;
+	lsp_regenerate_schedule(area, area->is_type, 0);
+
+	return NB_OK;
+}
+
+/*
+ * XPath:
+ * /frr-interface:lib/interface/frr-isisd:isis/fast-reroute/level-2/lfa/exclude-interface
+ */
+int lib_interface_isis_fast_reroute_level_2_lfa_exclude_interface_create(
+	struct nb_cb_create_args *args)
+{
+	struct isis_area *area;
+	struct isis_circuit *circuit;
+	const char *exclude_ifname;
+
+	if (args->event != NB_EV_APPLY)
+		return NB_OK;
+
+	circuit = nb_running_get_entry(args->dnode, NULL, true);
+	exclude_ifname = yang_dnode_get_string(args->dnode, NULL);
+
+	isis_lfa_excluded_iface_add(circuit, ISIS_LEVEL2, exclude_ifname);
+	area = circuit->area;
+	lsp_regenerate_schedule(area, area->is_type, 0);
+
+	return NB_OK;
+}
+
+int lib_interface_isis_fast_reroute_level_2_lfa_exclude_interface_destroy(
+	struct nb_cb_destroy_args *args)
+{
+	struct isis_area *area;
+	struct isis_circuit *circuit;
+	const char *exclude_ifname;
+
+	if (args->event != NB_EV_APPLY)
+		return NB_OK;
+
+	circuit = nb_running_get_entry(args->dnode, NULL, true);
+	exclude_ifname = yang_dnode_get_string(args->dnode, NULL);
+
+	isis_lfa_excluded_iface_delete(circuit, ISIS_LEVEL2, exclude_ifname);
+	area = circuit->area;
+	lsp_regenerate_schedule(area, area->is_type, 0);
+
+	return NB_OK;
+}
+
+/*
+ * XPath:
  * /frr-interface:lib/interface/frr-isisd:isis/fast-reroute/level-2/ti-lfa/enable
  */
 int lib_interface_isis_fast_reroute_level_2_ti_lfa_enable_modify(
@@ -3070,10 +3577,10 @@ int lib_interface_isis_fast_reroute_level_2_ti_lfa_enable_modify(
 	circuit = nb_running_get_entry(args->dnode, NULL, true);
 	circuit->tilfa_protection[1] = yang_dnode_get_bool(args->dnode, NULL);
 	if (circuit->tilfa_protection[1])
-		circuit->area->lfa_protected_links[1]++;
+		circuit->area->tilfa_protected_links[1]++;
 	else {
-		assert(circuit->area->lfa_protected_links[1] > 0);
-		circuit->area->lfa_protected_links[1]--;
+		assert(circuit->area->tilfa_protected_links[1] > 0);
+		circuit->area->tilfa_protected_links[1]--;
 	}
 
 	area = circuit->area;
diff --git a/isisd/isis_route.c b/isisd/isis_route.c
index d664a6f89..d32f219e9 100644
--- a/isisd/isis_route.c
+++ b/isisd/isis_route.c
@@ -183,7 +183,7 @@ static void isis_route_add_dummy_nexthops(struct isis_route_info *rinfo,
 static struct isis_route_info *
 isis_route_info_new(struct prefix *prefix, struct prefix_ipv6 *src_p,
 		    uint32_t cost, uint32_t depth, struct isis_sr_psid_info *sr,
-		    struct list *adjacencies)
+		    struct list *adjacencies, bool allow_ecmp)
 {
 	struct isis_route_info *rinfo;
 	struct isis_vertex_adj *vadj;
@@ -205,6 +205,8 @@ isis_route_info_new(struct prefix *prefix, struct prefix_ipv6 *src_p,
 		if (CHECK_FLAG(im->options, F_ISIS_UNIT_TEST)) {
 			isis_route_add_dummy_nexthops(rinfo, sadj->id, sr,
 						      label_stack);
+			if (!allow_ecmp)
+				break;
 			continue;
 		}
 
@@ -233,6 +235,8 @@ isis_route_info_new(struct prefix *prefix, struct prefix_ipv6 *src_p,
 		}
 		adjinfo2nexthop(prefix->family, rinfo->nexthops, adj, sr,
 				label_stack);
+		if (!allow_ecmp)
+			break;
 	}
 
 	rinfo->cost = cost;
@@ -339,8 +343,8 @@ static int isis_route_info_same(struct isis_route_info *new,
 struct isis_route_info *
 isis_route_create(struct prefix *prefix, struct prefix_ipv6 *src_p,
 		  uint32_t cost, uint32_t depth, struct isis_sr_psid_info *sr,
-		  struct list *adjacencies, struct isis_area *area,
-		  struct route_table *table)
+		  struct list *adjacencies, bool allow_ecmp,
+		  struct isis_area *area, struct route_table *table)
 {
 	struct route_node *route_node;
 	struct isis_route_info *rinfo_new, *rinfo_old, *route_info = NULL;
@@ -350,7 +354,7 @@ isis_route_create(struct prefix *prefix, struct prefix_ipv6 *src_p,
 		return NULL;
 
 	rinfo_new = isis_route_info_new(prefix, src_p, cost, depth, sr,
-					adjacencies);
+					adjacencies, allow_ecmp);
 	route_node = srcdest_rnode_get(table, prefix, src_p);
 
 	rinfo_old = route_node->info;
diff --git a/isisd/isis_route.h b/isisd/isis_route.h
index b5e4aed6c..0d4f88495 100644
--- a/isisd/isis_route.h
+++ b/isisd/isis_route.h
@@ -61,8 +61,8 @@ void adjinfo2nexthop(int family, struct list *nexthops,
 struct isis_route_info *
 isis_route_create(struct prefix *prefix, struct prefix_ipv6 *src_p,
 		  uint32_t cost, uint32_t depth, struct isis_sr_psid_info *sr,
-		  struct list *adjacencies, struct isis_area *area,
-		  struct route_table *table);
+		  struct list *adjacencies, bool allow_ecmp,
+		  struct isis_area *area, struct route_table *table);
 
 /* Walk the given table and install new routes to zebra and remove old ones.
  * route status is tracked using ISIS_ROUTE_FLAG_ACTIVE */
diff --git a/isisd/isis_spf.c b/isisd/isis_spf.c
index 58b0cf268..47918ef47 100644
--- a/isisd/isis_spf.c
+++ b/isisd/isis_spf.c
@@ -32,6 +32,7 @@
 #include "termtable.h"
 #include "memory.h"
 #include "prefix.h"
+#include "filter.h"
 #include "if.h"
 #include "hash.h"
 #include "table.h"
@@ -216,7 +217,7 @@ struct isis_vertex *isis_spf_prefix_sid_lookup(struct isis_spftree *spftree,
 	return hash_lookup(spftree->prefix_sids, &lookup);
 }
 
-static void isis_vertex_adj_free(void *arg)
+void isis_vertex_adj_free(void *arg)
 {
 	struct isis_vertex_adj *vadj = arg;
 
@@ -246,10 +247,10 @@ static struct isis_vertex *isis_vertex_new(struct isis_spftree *spftree,
 	return vertex;
 }
 
-static struct isis_vertex_adj *isis_vertex_adj_add(struct isis_spftree *spftree,
-						   struct isis_vertex *vertex,
-						   struct isis_spf_adj *sadj,
-						   struct isis_prefix_sid *psid)
+struct isis_vertex_adj *
+isis_vertex_adj_add(struct isis_spftree *spftree, struct isis_vertex *vertex,
+		    struct list *vadj_list, struct isis_spf_adj *sadj,
+		    struct isis_prefix_sid *psid, bool last_hop)
 {
 	struct isis_vertex_adj *vadj;
 
@@ -262,9 +263,6 @@ static struct isis_vertex_adj *isis_vertex_adj_add(struct isis_spftree *spftree,
 				"ISIS-SPF: ignoring different Prefix-SID for route %pFX",
 				&vertex->N.ip.p.dest);
 		else {
-			bool last_hop;
-
-			last_hop = (vertex->depth == 2);
 			vadj->sr.sid = *psid;
 			vadj->sr.label = sr_prefix_out_label(
 				spftree->lspdb, vertex->N.ip.p.dest.family,
@@ -273,7 +271,7 @@ static struct isis_vertex_adj *isis_vertex_adj_add(struct isis_spftree *spftree,
 				vadj->sr.present = true;
 		}
 	}
-	listnode_add(vertex->Adj_N, vadj);
+	listnode_add(vadj_list, vadj);
 
 	return vadj;
 }
@@ -528,6 +526,7 @@ isis_spf_add2tent(struct isis_spftree *spftree, enum vertextype vtype, void *id,
 {
 	struct isis_vertex *vertex;
 	struct listnode *node;
+	bool last_hop;
 	char buff[VID2STR_BUFFER];
 
 	vertex = isis_find_vertex(&spftree->paths, id, vtype);
@@ -593,14 +592,16 @@ isis_spf_add2tent(struct isis_spftree *spftree, enum vertextype vtype, void *id,
 	if (CHECK_FLAG(spftree->flags, F_SPFTREE_HOPCOUNT_METRIC))
 		vertex_update_firsthops(vertex, parent);
 
+	last_hop = (vertex->depth == 2);
 	if (parent && parent->Adj_N && listcount(parent->Adj_N) > 0) {
 		struct isis_vertex_adj *parent_vadj;
 
 		for (ALL_LIST_ELEMENTS_RO(parent->Adj_N, node, parent_vadj))
-			isis_vertex_adj_add(spftree, vertex, parent_vadj->sadj,
-					    psid);
+			isis_vertex_adj_add(spftree, vertex, vertex->Adj_N,
+					    parent_vadj->sadj, psid, last_hop);
 	} else if (sadj) {
-		isis_vertex_adj_add(spftree, vertex, sadj, psid);
+		isis_vertex_adj_add(spftree, vertex, vertex->Adj_N, sadj, psid,
+				    last_hop);
 	}
 
 #ifdef EXTREME_DEBUG
@@ -628,9 +629,13 @@ static void isis_spf_add_local(struct isis_spftree *spftree,
 	if (vertex) {
 		/* C.2.5   c) */
 		if (vertex->d_N == cost) {
-			if (sadj)
-				isis_vertex_adj_add(spftree, vertex, sadj,
-						    psid);
+			if (sadj) {
+				bool last_hop = (vertex->depth == 2);
+
+				isis_vertex_adj_add(spftree, vertex,
+						    vertex->Adj_N, sadj, psid,
+						    last_hop);
+			}
 			/*       d) */
 			if (!CHECK_FLAG(spftree->flags,
 					F_SPFTREE_NO_ADJACENCIES)
@@ -718,11 +723,16 @@ static void process_N(struct isis_spftree *spftree, enum vertextype vtype,
 			struct isis_vertex_adj *parent_vadj;
 			for (ALL_LIST_ELEMENTS_RO(parent->Adj_N, node,
 						  parent_vadj))
-				if (!isis_vertex_adj_exists(spftree, vertex,
-							    parent_vadj->sadj))
+				if (!isis_vertex_adj_exists(
+					    spftree, vertex,
+					    parent_vadj->sadj)) {
+					bool last_hop = (vertex->depth == 2);
+
 					isis_vertex_adj_add(spftree, vertex,
+							    vertex->Adj_N,
 							    parent_vadj->sadj,
-							    psid);
+							    psid, last_hop);
+				}
 			if (CHECK_FLAG(spftree->flags,
 				       F_SPFTREE_HOPCOUNT_METRIC))
 				vertex_update_firsthops(vertex, parent);
@@ -771,7 +781,7 @@ static int isis_spf_process_lsp(struct isis_spftree *spftree,
 	bool has_valid_psid;
 
 	if (isis_lfa_excise_node_check(spftree, lsp->hdr.lsp_id)) {
-		if (IS_DEBUG_TILFA)
+		if (IS_DEBUG_LFA)
 			zlog_debug("ISIS-LFA: excising node %s",
 				   print_sys_hostname(lsp->hdr.lsp_id));
 		return ISIS_OK;
@@ -1140,7 +1150,7 @@ static void isis_spf_preload_tent(struct isis_spftree *spftree,
 			adj_id = sadj->id;
 
 		if (isis_lfa_excise_adj_check(spftree, adj_id)) {
-			if (IS_DEBUG_TILFA)
+			if (IS_DEBUG_LFA)
 				zlog_debug("ISIS-SPF: excising adjacency %s",
 					   isis_format_id(sadj->id,
 							  ISIS_SYS_ID_LEN + 1));
@@ -1158,9 +1168,9 @@ static void isis_spf_preload_tent(struct isis_spftree *spftree,
 						   : VTYPE_NONPSEUDO_TE_IS,
 					   sadj->id, sadj, metric, NULL,
 					   parent);
-		} else if (sadj->lan.lsp_pseudo) {
-			isis_spf_process_lsp(spftree, sadj->lan.lsp_pseudo,
-					     metric, 0, spftree->sysid, parent);
+		} else if (sadj->lsp) {
+			isis_spf_process_lsp(spftree, sadj->lsp, metric, 0,
+					     spftree->sysid, parent);
 		}
 	}
 }
@@ -1243,12 +1253,24 @@ static void spf_adj_list_parse_tlv(struct isis_spftree *spftree,
 				   struct isis_ext_subtlvs *subtlvs)
 {
 	struct isis_spf_adj *sadj;
+	uint8_t lspid[ISIS_SYS_ID_LEN + 2];
+	struct isis_lsp *lsp;
 	uint8_t flags = 0;
 
 	/* Skip self in the pseudonode. */
 	if (desig_is_id && !memcmp(id, spftree->sysid, ISIS_SYS_ID_LEN))
 		return;
 
+	/* Find LSP from the adjacency. */
+	memcpy(lspid, id, ISIS_SYS_ID_LEN + 1);
+	LSP_FRAGMENT(lspid) = 0;
+	lsp = lsp_search(spftree->lspdb, lspid);
+	if (lsp == NULL || lsp->hdr.rem_lifetime == 0) {
+		zlog_warn("ISIS-SPF: No LSP found from root to L%d %s",
+			  spftree->level, rawlspid_print(id));
+		return;
+	}
+
 	sadj = XCALLOC(MTYPE_ISIS_SPF_ADJ, sizeof(*sadj));
 	memcpy(sadj->id, id, sizeof(sadj->id));
 	if (desig_is_id) {
@@ -1260,9 +1282,14 @@ static void spf_adj_list_parse_tlv(struct isis_spftree *spftree,
 		sadj->metric = metric;
 	if (oldmetric)
 		SET_FLAG(flags, F_ISIS_SPF_ADJ_OLDMETRIC);
+	sadj->lsp = lsp;
 	sadj->subtlvs = subtlvs;
 	sadj->flags = flags;
 
+	if ((oldmetric && metric == ISIS_NARROW_METRIC_INFINITY)
+	    || (!oldmetric && metric == ISIS_WIDE_METRIC_INFINITY))
+		SET_FLAG(flags, F_ISIS_SPF_ADJ_METRIC_INFINITY);
+
 	/* Set real adjacency. */
 	if (!CHECK_FLAG(spftree->flags, F_SPFTREE_NO_ADJACENCIES)
 	    && !LSP_PSEUDO_ID(id)) {
@@ -1294,24 +1321,8 @@ static void spf_adj_list_parse_tlv(struct isis_spftree *spftree,
 	}
 
 	/* Parse pseudonode LSP too. */
-	if (LSP_PSEUDO_ID(id)) {
-		uint8_t lspid[ISIS_SYS_ID_LEN + 2];
-		struct isis_lsp *lsp_pseudo;
-
-		memcpy(lspid, id, ISIS_SYS_ID_LEN + 1);
-		LSP_FRAGMENT(lspid) = 0;
-		lsp_pseudo = lsp_search(spftree->lspdb, lspid);
-		if (lsp_pseudo == NULL || lsp_pseudo->hdr.rem_lifetime == 0) {
-			zlog_warn(
-				"ISIS-SPF: No LSP found from root to L%d DR %s",
-				spftree->level, rawlspid_print(id));
-			return;
-		}
-
-		sadj->lan.lsp_pseudo = lsp_pseudo;
-		spf_adj_list_parse_lsp(spftree, adj_list, lsp_pseudo, id,
-				       metric);
-	}
+	if (LSP_PSEUDO_ID(id))
+		spf_adj_list_parse_lsp(spftree, adj_list, lsp, id, metric);
 }
 
 static void spf_adj_list_parse_lsp(struct isis_spftree *spftree,
@@ -1418,32 +1429,65 @@ static void init_spt(struct isis_spftree *spftree, int mtid)
 	list_delete_all_node(spftree->sadj_list);
 	isis_vertex_queue_clear(&spftree->tents);
 	isis_vertex_queue_clear(&spftree->paths);
+	memset(&spftree->lfa.protection_counters, 0,
+	       sizeof(spftree->lfa.protection_counters));
 
 	spftree->mtid = mtid;
 }
 
+static enum spf_prefix_priority
+spf_prefix_priority(struct isis_spftree *spftree, struct isis_vertex *vertex)
+{
+	struct isis_area *area = spftree->area;
+	struct prefix *prefix = &vertex->N.ip.p.dest;
+
+	for (int priority = SPF_PREFIX_PRIO_CRITICAL;
+	     priority <= SPF_PREFIX_PRIO_MEDIUM; priority++) {
+		struct spf_prefix_priority_acl *ppa;
+		enum filter_type ret = FILTER_PERMIT;
+
+		ppa = &area->spf_prefix_priorities[priority];
+		switch (spftree->family) {
+		case AF_INET:
+			ret = access_list_apply(ppa->list_v4, prefix);
+			break;
+		case AF_INET6:
+			ret = access_list_apply(ppa->list_v6, prefix);
+			break;
+		default:
+			break;
+		}
+
+		if (ret == FILTER_PERMIT)
+			return priority;
+	}
+
+	/* Assign medium priority to loopback prefixes by default. */
+	if (is_host_route(prefix))
+		return SPF_PREFIX_PRIO_MEDIUM;
+
+	return SPF_PREFIX_PRIO_LOW;
+}
+
 static void spf_path_process(struct isis_spftree *spftree,
 			     struct isis_vertex *vertex)
 {
 	struct isis_area *area = spftree->area;
+	int level = spftree->level;
 	char buff[VID2STR_BUFFER];
 
-	if (VTYPE_IS(vertex->type)
+	if (spftree->type == SPF_TYPE_TI_LFA && VTYPE_IS(vertex->type)
 	    && !CHECK_FLAG(spftree->flags, F_SPFTREE_NO_ADJACENCIES)) {
 		if (listcount(vertex->Adj_N) > 0) {
-			if (spftree->type == SPF_TYPE_TI_LFA) {
-				struct isis_adjacency *adj;
+			struct isis_adjacency *adj;
 
-				if (isis_lfa_check(spftree, vertex) != 0)
-					return;
+			if (isis_tilfa_check(spftree, vertex) != 0)
+				return;
 
-				adj = isis_adj_find(area, spftree->level,
-						    vertex->N.id);
-				if (adj)
-					sr_adj_sid_add_single(
-						adj, spftree->family, true,
-						vertex->Adj_N);
-			}
+			adj = isis_adj_find(area, level, vertex->N.id);
+			if (adj)
+				sr_adj_sid_add_single(adj, spftree->family,
+						      true, vertex->Adj_N);
 		} else if (IS_DEBUG_SPF_EVENTS)
 			zlog_debug(
 				"ISIS-SPF: no adjacencies, do not install backup Adj-SID for %s depth %d dist %d",
@@ -1453,21 +1497,59 @@ static void spf_path_process(struct isis_spftree *spftree,
 
 	if (VTYPE_IP(vertex->type)
 	    && !CHECK_FLAG(spftree->flags, F_SPFTREE_NO_ROUTES)) {
+		enum spf_prefix_priority priority;
+
+		priority = spf_prefix_priority(spftree, vertex);
+		vertex->N.ip.priority = priority;
 		if (vertex->depth == 1 || listcount(vertex->Adj_N) > 0) {
 			struct route_table *route_table;
+			bool allow_ecmp;
 
 			if (spftree->type == SPF_TYPE_TI_LFA) {
-				if (isis_lfa_check(spftree, vertex) != 0)
+				struct isis_spftree *pre_spftree;
+
+				if (priority
+				    > area->lfa_priority_limit[level - 1]) {
+					if (IS_DEBUG_LFA)
+						zlog_debug(
+							"ISIS-LFA: skipping %s %s (low prefix priority)",
+							vtype2string(
+								vertex->type),
+							vid2string(
+								vertex, buff,
+								sizeof(buff)));
 					return;
-				route_table = spftree->lfa.old.spftree
-						      ->route_table_backup;
-			} else
+				}
+
+				if (isis_tilfa_check(spftree, vertex) != 0)
+					return;
+
+				pre_spftree = spftree->lfa.old.spftree;
+				route_table = pre_spftree->route_table_backup;
+				allow_ecmp = area->lfa_load_sharing[level - 1];
+				pre_spftree->lfa.protection_counters
+					.tilfa[vertex->N.ip.priority] += 1;
+			} else {
 				route_table = spftree->route_table;
+				allow_ecmp = true;
+
+				/*
+				 * Update LFA protection counters (ignore local
+				 * routes).
+				 */
+				if (vertex->depth > 1) {
+					spftree->lfa.protection_counters
+						.total[priority] += 1;
+					if (listcount(vertex->Adj_N) > 1)
+						spftree->lfa.protection_counters
+							.ecmp[priority] += 1;
+				}
+			}
 
-			isis_route_create(&vertex->N.ip.p.dest,
-					  &vertex->N.ip.p.src, vertex->d_N,
-					  vertex->depth, &vertex->N.ip.sr,
-					  vertex->Adj_N, area, route_table);
+			isis_route_create(
+				&vertex->N.ip.p.dest, &vertex->N.ip.p.src,
+				vertex->d_N, vertex->depth, &vertex->N.ip.sr,
+				vertex->Adj_N, allow_ecmp, area, route_table);
 		} else if (IS_DEBUG_SPF_EVENTS)
 			zlog_debug(
 				"ISIS-SPF: no adjacencies, do not install route for %s depth %d dist %d",
@@ -1641,7 +1723,8 @@ static void isis_run_spf_with_protection(struct isis_area *area,
 	isis_run_spf(spftree);
 
 	/* Run LFA protection if configured. */
-	if (area->lfa_protected_links[spftree->level - 1] > 0)
+	if (area->lfa_protected_links[spftree->level - 1] > 0
+	    || area->tilfa_protected_links[spftree->level - 1] > 0)
 		isis_spf_run_lfa(area, spftree);
 }
 
@@ -2281,10 +2364,223 @@ DEFUN(show_isis_route, show_isis_route_cmd,
 	return CMD_SUCCESS;
 }
 
+static void isis_print_frr_summary_line(struct ttable *tt,
+					const char *protection,
+					uint32_t counters[SPF_PREFIX_PRIO_MAX])
+{
+	uint32_t critical, high, medium, low, total;
+
+	critical = counters[SPF_PREFIX_PRIO_CRITICAL];
+	high = counters[SPF_PREFIX_PRIO_HIGH];
+	medium = counters[SPF_PREFIX_PRIO_MEDIUM];
+	low = counters[SPF_PREFIX_PRIO_LOW];
+	total = critical + high + medium + low;
+
+	ttable_add_row(tt, "%s|%u|%u|%u|%u|%u", protection, critical, high,
+		       medium, low, total);
+}
+
+static void
+isis_print_frr_summary_line_coverage(struct ttable *tt, const char *protection,
+				     double counters[SPF_PREFIX_PRIO_MAX],
+				     double total)
+{
+	double critical, high, medium, low;
+
+	critical = counters[SPF_PREFIX_PRIO_CRITICAL] * 100;
+	high = counters[SPF_PREFIX_PRIO_HIGH] * 100;
+	medium = counters[SPF_PREFIX_PRIO_MEDIUM] * 100;
+	low = counters[SPF_PREFIX_PRIO_LOW] * 100;
+	total *= 100;
+
+	ttable_add_row(tt, "%s|%.2f%%|%.2f%%|%.2f%%|%.2f%%|%.2f%%", protection,
+		       critical, high, medium, low, total);
+}
+
+static void isis_print_frr_summary(struct vty *vty,
+				   struct isis_spftree *spftree)
+{
+	struct ttable *tt;
+	char *table;
+	const char *tree_id_text = NULL;
+	uint32_t protectd[SPF_PREFIX_PRIO_MAX] = {0};
+	uint32_t unprotected[SPF_PREFIX_PRIO_MAX] = {0};
+	double coverage[SPF_PREFIX_PRIO_MAX] = {0};
+	uint32_t protected_total = 0, grand_total = 0;
+	double coverage_total;
+
+	if (!spftree)
+		return;
+
+	switch (spftree->tree_id) {
+	case SPFTREE_IPV4:
+		tree_id_text = "IPv4";
+		break;
+	case SPFTREE_IPV6:
+		tree_id_text = "IPv6";
+		break;
+	case SPFTREE_DSTSRC:
+		tree_id_text = "IPv6 (dst-src routing)";
+		break;
+	case SPFTREE_COUNT:
+		assert(!"isis_print_frr_summary shouldn't be called with SPFTREE_COUNT as type");
+		return;
+	}
+
+	vty_out(vty, " IS-IS %s %s Fast ReRoute summary:\n\n",
+		circuit_t2string(spftree->level), tree_id_text);
+
+	/* Prepare table. */
+	tt = ttable_new(&ttable_styles[TTSTYLE_BLANK]);
+	ttable_add_row(
+		tt,
+		"Protection \\ Priority|Critical|High    |Medium  |Low     |Total");
+	tt->style.cell.rpad = 2;
+	tt->style.corner = '+';
+	ttable_restyle(tt);
+	ttable_rowseps(tt, 0, BOTTOM, true, '-');
+
+	/* Compute unprotected and coverage totals. */
+	for (int priority = SPF_PREFIX_PRIO_CRITICAL;
+	     priority < SPF_PREFIX_PRIO_MAX; priority++) {
+		uint32_t *lfa = spftree->lfa.protection_counters.lfa;
+		uint32_t *rlfa = spftree->lfa.protection_counters.rlfa;
+		uint32_t *tilfa = spftree->lfa.protection_counters.tilfa;
+		uint32_t *ecmp = spftree->lfa.protection_counters.ecmp;
+		uint32_t *total = spftree->lfa.protection_counters.total;
+
+		protectd[priority] = lfa[priority] + rlfa[priority]
+				     + tilfa[priority] + ecmp[priority];
+		/* Safeguard to protect against possible inconsistencies. */
+		if (protectd[priority] > total[priority])
+			protectd[priority] = total[priority];
+		unprotected[priority] = total[priority] - protectd[priority];
+		protected_total += protectd[priority];
+		grand_total += total[priority];
+
+		if (!total[priority])
+			coverage[priority] = 0;
+		else
+			coverage[priority] =
+				protectd[priority] / (double)total[priority];
+	}
+
+	if (!grand_total)
+		coverage_total = 0;
+	else
+		coverage_total = protected_total / (double)grand_total;
+
+	/* Add rows. */
+	isis_print_frr_summary_line(tt, "Classic LFA",
+				    spftree->lfa.protection_counters.lfa);
+	isis_print_frr_summary_line(tt, "Remote LFA",
+				    spftree->lfa.protection_counters.rlfa);
+	isis_print_frr_summary_line(tt, "Topology Independent LFA",
+				    spftree->lfa.protection_counters.tilfa);
+	isis_print_frr_summary_line(tt, "ECMP",
+				    spftree->lfa.protection_counters.ecmp);
+	isis_print_frr_summary_line(tt, "Unprotected", unprotected);
+	isis_print_frr_summary_line_coverage(tt, "Protection coverage",
+					     coverage, coverage_total);
+
+	/* Dump the generated table. */
+	table = ttable_dump(tt, "\n");
+	vty_out(vty, "%s\n", table);
+	XFREE(MTYPE_TMP, table);
+	ttable_del(tt);
+}
+
+static void show_isis_frr_summary_common(struct vty *vty, int levels,
+					 struct isis *isis)
+{
+	struct listnode *node;
+	struct isis_area *area;
+
+	if (!isis->area_list || isis->area_list->count == 0)
+		return;
+
+	for (ALL_LIST_ELEMENTS_RO(isis->area_list, node, area)) {
+		vty_out(vty, "Area %s:\n",
+			area->area_tag ? area->area_tag : "null");
+
+		for (int level = ISIS_LEVEL1; level <= ISIS_LEVELS; level++) {
+			if ((level & levels) == 0)
+				continue;
+
+			if (area->ip_circuits > 0) {
+				isis_print_frr_summary(
+					vty,
+					area->spftree[SPFTREE_IPV4][level - 1]);
+			}
+			if (area->ipv6_circuits > 0) {
+				isis_print_frr_summary(
+					vty,
+					area->spftree[SPFTREE_IPV6][level - 1]);
+			}
+			if (isis_area_ipv6_dstsrc_enabled(area)) {
+				isis_print_frr_summary(
+					vty, area->spftree[SPFTREE_DSTSRC]
+							  [level - 1]);
+			}
+		}
+	}
+}
+
+DEFUN(show_isis_frr_summary, show_isis_frr_summary_cmd,
+      "show " PROTO_NAME
+      " [vrf <NAME|all>] fast-reroute summary"
+#ifndef FABRICD
+      " [<level-1|level-2>]"
+#endif
+      ,
+      SHOW_STR PROTO_HELP VRF_FULL_CMD_HELP_STR
+      "IS-IS FRR information\n"
+      "FRR summary\n"
+#ifndef FABRICD
+      "level-1 routes\n"
+      "level-2 routes\n"
+#endif
+)
+{
+	int levels;
+	struct isis *isis;
+	struct listnode *node;
+	const char *vrf_name = VRF_DEFAULT_NAME;
+	bool all_vrf = false;
+	int idx = 0;
+
+	if (argv_find(argv, argc, "level-1", &idx))
+		levels = ISIS_LEVEL1;
+	else if (argv_find(argv, argc, "level-2", &idx))
+		levels = ISIS_LEVEL2;
+	else
+		levels = ISIS_LEVEL1 | ISIS_LEVEL2;
+
+	if (!im) {
+		vty_out(vty, "IS-IS Routing Process not enabled\n");
+		return CMD_SUCCESS;
+	}
+	ISIS_FIND_VRF_ARGS(argv, argc, idx, vrf_name, all_vrf);
+
+	if (vrf_name) {
+		if (all_vrf) {
+			for (ALL_LIST_ELEMENTS_RO(im->isis, node, isis))
+				show_isis_frr_summary_common(vty, levels, isis);
+			return CMD_SUCCESS;
+		}
+		isis = isis_lookup_by_vrfname(vrf_name);
+		if (isis != NULL)
+			show_isis_frr_summary_common(vty, levels, isis);
+	}
+
+	return CMD_SUCCESS;
+}
+
 void isis_spf_init(void)
 {
 	install_element(VIEW_NODE, &show_isis_topology_cmd);
 	install_element(VIEW_NODE, &show_isis_route_cmd);
+	install_element(VIEW_NODE, &show_isis_frr_summary_cmd);
 
 	/* Register hook(s). */
 	hook_register(isis_adj_state_change_hook, spf_adj_state_change);
diff --git a/isisd/isis_spf.h b/isisd/isis_spf.h
index ad15d3e3c..5b6fcdaf6 100644
--- a/isisd/isis_spf.h
+++ b/isisd/isis_spf.h
@@ -39,13 +39,14 @@ struct isis_spf_adj {
 	struct isis_adjacency *adj;
 	uint32_t metric;
 	struct isis_ext_subtlvs *subtlvs;
+	struct isis_lsp *lsp;
 	struct {
 		uint8_t desig_is_id[ISIS_SYS_ID_LEN + 1];
-		struct isis_lsp *lsp_pseudo;
 	} lan;
 	uint8_t flags;
 #define F_ISIS_SPF_ADJ_BROADCAST 0x01
 #define F_ISIS_SPF_ADJ_OLDMETRIC 0x02
+#define F_ISIS_SPF_ADJ_METRIC_INFINITY 0x04
 };
 
 struct isis_spftree *isis_spftree_new(struct isis_area *area,
diff --git a/isisd/isis_spf_private.h b/isisd/isis_spf_private.h
index 9cb1a39b8..b7f326ca8 100644
--- a/isisd/isis_spf_private.h
+++ b/isisd/isis_spf_private.h
@@ -54,6 +54,7 @@ struct isis_vertex_adj {
 	struct isis_spf_adj *sadj;
 	struct isis_sr_psid_info sr;
 	struct mpls_label_stack *label_stack;
+	uint32_t lfa_metric;
 };
 
 /*
@@ -66,6 +67,7 @@ struct isis_vertex {
 		struct {
 			struct prefix_pair p;
 			struct isis_sr_psid_info sr;
+			enum spf_prefix_priority priority;
 		} ip;
 	} N;
 	uint32_t d_N;	  /* d(N) Distance from this IS      */
@@ -193,6 +195,11 @@ static void isis_vertex_del(struct isis_vertex *vertex)
 bool isis_vertex_adj_exists(const struct isis_spftree *spftree,
 			    const struct isis_vertex *vertex,
 			    const struct isis_spf_adj *sadj);
+void isis_vertex_adj_free(void *arg);
+struct isis_vertex_adj *
+isis_vertex_adj_add(struct isis_spftree *spftree, struct isis_vertex *vertex,
+		    struct list *vadj_list, struct isis_spf_adj *sadj,
+		    struct isis_prefix_sid *psid, bool last_hop);
 
 __attribute__((__unused__))
 static void isis_vertex_queue_clear(struct isis_vertex_queue *queue)
@@ -341,6 +348,15 @@ struct isis_spftree {
 		/* P-space and Q-space. */
 		struct isis_spf_nodes p_space;
 		struct isis_spf_nodes q_space;
+
+		/* Protection counters. */
+		struct {
+			uint32_t lfa[SPF_PREFIX_PRIO_MAX];
+			uint32_t rlfa[SPF_PREFIX_PRIO_MAX];
+			uint32_t tilfa[SPF_PREFIX_PRIO_MAX];
+			uint32_t ecmp[SPF_PREFIX_PRIO_MAX];
+			uint32_t total[SPF_PREFIX_PRIO_MAX];
+		} protection_counters;
 	} lfa;
 	uint8_t flags;
 };
diff --git a/isisd/isis_tlvs.h b/isisd/isis_tlvs.h
index 54ded8121..037f91f0b 100644
--- a/isisd/isis_tlvs.h
+++ b/isisd/isis_tlvs.h
@@ -42,6 +42,9 @@ struct isis_area_address {
 	uint8_t len;
 };
 
+#define ISIS_WIDE_METRIC_INFINITY   0xFFFFFE
+#define ISIS_NARROW_METRIC_INFINITY 62
+
 struct isis_oldstyle_reach;
 struct isis_oldstyle_reach {
 	struct isis_oldstyle_reach *next;
diff --git a/isisd/isisd.c b/isisd/isisd.c
index 950cdc281..827e022ba 100644
--- a/isisd/isisd.c
+++ b/isisd/isisd.c
@@ -31,6 +31,7 @@
 #include "linklist.h"
 #include "if.h"
 #include "hash.h"
+#include "filter.h"
 #include "stream.h"
 #include "prefix.h"
 #include "table.h"
@@ -77,7 +78,7 @@ unsigned long debug_bfd;
 unsigned long debug_tx_queue;
 unsigned long debug_sr;
 unsigned long debug_ldp_sync;
-unsigned long debug_tilfa;
+unsigned long debug_lfa;
 
 DEFINE_QOBJ_TYPE(isis_area)
 
@@ -310,6 +311,10 @@ struct isis_area *isis_area_create(const char *area_tag, const char *vrf_name)
 	area->lsp_frag_threshold = 90; /* not currently configurable */
 	area->lsp_mtu =
 		yang_get_default_uint16("/frr-isisd:isis/instance/lsp/mtu");
+	area->lfa_load_sharing[0] = yang_get_default_bool(
+		"/frr-isisd:isis/instance/fast-reroute/level-1/lfa/load-sharing");
+	area->lfa_load_sharing[1] = yang_get_default_bool(
+		"/frr-isisd:isis/instance/fast-reroute/level-2/lfa/load-sharing");
 #else
 	area->max_lsp_lifetime[0] = DEFAULT_LSP_LIFETIME;    /* 1200 */
 	area->max_lsp_lifetime[1] = DEFAULT_LSP_LIFETIME;    /* 1200 */
@@ -324,7 +329,13 @@ struct isis_area *isis_area_create(const char *area_tag, const char *vrf_name)
 	area->newmetric = 1;
 	area->lsp_frag_threshold = 90;
 	area->lsp_mtu = DEFAULT_LSP_MTU;
+	area->lfa_load_sharing[0] = true;
+	area->lfa_load_sharing[1] = true;
 #endif /* ifndef FABRICD */
+	area->lfa_priority_limit[0] = SPF_PREFIX_PRIO_LOW;
+	area->lfa_priority_limit[1] = SPF_PREFIX_PRIO_LOW;
+	isis_lfa_tiebreakers_init(area, ISIS_LEVEL1);
+	isis_lfa_tiebreakers_init(area, ISIS_LEVEL2);
 
 	area_mt_init(area);
 
@@ -461,6 +472,16 @@ void isis_area_destroy(struct isis_area *area)
 	}
 	area->area_addrs = NULL;
 
+	for (int i = SPF_PREFIX_PRIO_CRITICAL; i <= SPF_PREFIX_PRIO_MEDIUM;
+	     i++) {
+		struct spf_prefix_priority_acl *ppa;
+
+		ppa = &area->spf_prefix_priorities[i];
+		XFREE(MTYPE_ISIS_ACL_NAME, ppa->name);
+	}
+	isis_lfa_tiebreakers_clear(area, ISIS_LEVEL1);
+	isis_lfa_tiebreakers_clear(area, ISIS_LEVEL2);
+
 	thread_cancel(&area->t_tick);
 	thread_cancel(&area->t_lsp_refresh[0]);
 	thread_cancel(&area->t_lsp_refresh[1]);
@@ -605,6 +626,29 @@ void isis_terminate()
 		isis_finish(isis);
 }
 
+void isis_filter_update(struct access_list *access)
+{
+	struct isis *isis;
+	struct isis_area *area;
+	struct listnode *node, *anode;
+
+	for (ALL_LIST_ELEMENTS_RO(im->isis, node, isis)) {
+		for (ALL_LIST_ELEMENTS_RO(isis->area_list, anode, area)) {
+			for (int i = SPF_PREFIX_PRIO_CRITICAL;
+			     i <= SPF_PREFIX_PRIO_MEDIUM; i++) {
+				struct spf_prefix_priority_acl *ppa;
+
+				ppa = &area->spf_prefix_priorities[i];
+				ppa->list_v4 =
+					access_list_lookup(AFI_IP, ppa->name);
+				ppa->list_v6 =
+					access_list_lookup(AFI_IP6, ppa->name);
+			}
+			lsp_regenerate_schedule(area, area->is_type, 0);
+		}
+	}
+}
+
 #ifdef FABRICD
 static void area_set_mt_enabled(struct isis_area *area, uint16_t mtid,
 				bool enabled)
@@ -1199,8 +1243,8 @@ void print_debug(struct vty *vty, int flags, int onoff)
 	if (flags & DEBUG_SR)
 		vty_out(vty, "IS-IS Segment Routing events debugging is %s\n",
 			onoffs);
-	if (flags & DEBUG_TILFA)
-		vty_out(vty, "IS-IS TI-LFA events debugging is %s\n", onoffs);
+	if (flags & DEBUG_LFA)
+		vty_out(vty, "IS-IS LFA events debugging is %s\n", onoffs);
 	if (flags & DEBUG_UPDATE_PACKETS)
 		vty_out(vty, "IS-IS Update related packet debugging is %s\n",
 			onoffs);
@@ -1295,8 +1339,8 @@ static int config_write_debug(struct vty *vty)
 		vty_out(vty, "debug " PROTO_NAME " sr-events\n");
 		write++;
 	}
-	if (IS_DEBUG_TILFA) {
-		vty_out(vty, "debug " PROTO_NAME " ti-lfa\n");
+	if (IS_DEBUG_LFA) {
+		vty_out(vty, "debug " PROTO_NAME " lfa\n");
 		write++;
 	}
 	if (IS_DEBUG_UPDATE_PACKETS) {
@@ -1529,29 +1573,29 @@ DEFUN (no_debug_isis_srevents,
 	return CMD_SUCCESS;
 }
 
-DEFUN (debug_isis_tilfa,
-       debug_isis_tilfa_cmd,
-       "debug " PROTO_NAME " ti-lfa",
+DEFUN (debug_isis_lfa,
+       debug_isis_lfa_cmd,
+       "debug " PROTO_NAME " lfa",
        DEBUG_STR
        PROTO_HELP
-       "IS-IS TI-LFA Events\n")
+       "IS-IS LFA Events\n")
 {
-	debug_tilfa |= DEBUG_TILFA;
-	print_debug(vty, DEBUG_TILFA, 1);
+	debug_lfa |= DEBUG_LFA;
+	print_debug(vty, DEBUG_LFA, 1);
 
 	return CMD_SUCCESS;
 }
 
-DEFUN (no_debug_isis_tilfa,
-       no_debug_isis_tilfa_cmd,
-       "no debug " PROTO_NAME " ti-lfa",
+DEFUN (no_debug_isis_lfa,
+       no_debug_isis_lfa_cmd,
+       "no debug " PROTO_NAME " lfa",
        NO_STR
        UNDEBUG_STR
        PROTO_HELP
-       "IS-IS TI-LFA Events\n")
+       "IS-IS LFA Events\n")
 {
-	debug_tilfa &= ~DEBUG_TILFA;
-	print_debug(vty, DEBUG_TILFA, 0);
+	debug_lfa &= ~DEBUG_LFA;
+	print_debug(vty, DEBUG_LFA, 0);
 
 	return CMD_SUCCESS;
 }
@@ -2892,8 +2936,8 @@ void isis_init(void)
 	install_element(ENABLE_NODE, &no_debug_isis_spfevents_cmd);
 	install_element(ENABLE_NODE, &debug_isis_srevents_cmd);
 	install_element(ENABLE_NODE, &no_debug_isis_srevents_cmd);
-	install_element(ENABLE_NODE, &debug_isis_tilfa_cmd);
-	install_element(ENABLE_NODE, &no_debug_isis_tilfa_cmd);
+	install_element(ENABLE_NODE, &debug_isis_lfa_cmd);
+	install_element(ENABLE_NODE, &no_debug_isis_lfa_cmd);
 	install_element(ENABLE_NODE, &debug_isis_rtevents_cmd);
 	install_element(ENABLE_NODE, &no_debug_isis_rtevents_cmd);
 	install_element(ENABLE_NODE, &debug_isis_events_cmd);
@@ -2923,8 +2967,8 @@ void isis_init(void)
 	install_element(CONFIG_NODE, &no_debug_isis_spfevents_cmd);
 	install_element(CONFIG_NODE, &debug_isis_srevents_cmd);
 	install_element(CONFIG_NODE, &no_debug_isis_srevents_cmd);
-	install_element(CONFIG_NODE, &debug_isis_tilfa_cmd);
-	install_element(CONFIG_NODE, &no_debug_isis_tilfa_cmd);
+	install_element(CONFIG_NODE, &debug_isis_lfa_cmd);
+	install_element(CONFIG_NODE, &no_debug_isis_lfa_cmd);
 	install_element(CONFIG_NODE, &debug_isis_rtevents_cmd);
 	install_element(CONFIG_NODE, &no_debug_isis_rtevents_cmd);
 	install_element(CONFIG_NODE, &debug_isis_events_cmd);
diff --git a/isisd/isisd.h b/isisd/isisd.h
index 921df4d7e..4618d14af 100644
--- a/isisd/isisd.h
+++ b/isisd/isisd.h
@@ -33,6 +33,7 @@
 #include "isisd/isis_sr.h"
 #include "isis_flags.h"
 #include "isis_lsp.h"
+#include "isis_lfa.h"
 #include "isis_memory.h"
 #include "qobj.h"
 #include "ldp_sync.h"
@@ -188,8 +189,15 @@ struct isis_area {
 	struct isis_sr_db srdb;
 	int ipv6_circuits;
 	bool purge_originator;
+	/* SPF prefix priorities. */
+	struct spf_prefix_priority_acl
+		spf_prefix_priorities[SPF_PREFIX_PRIO_MAX];
 	/* Fast Re-Route information. */
 	size_t lfa_protected_links[ISIS_LEVELS];
+	size_t lfa_load_sharing[ISIS_LEVELS];
+	enum spf_prefix_priority lfa_priority_limit[ISIS_LEVELS];
+	struct lfa_tiebreaker_tree_head lfa_tiebreakers[ISIS_LEVELS];
+	size_t tilfa_protected_links[ISIS_LEVELS];
 	/* Counters */
 	uint32_t circuit_state_changes;
 	struct isis_redist redist_settings[REDIST_PROTOCOL_COUNT]
@@ -231,6 +239,7 @@ struct isis_area *isis_area_lookup_by_vrf(const char *area_tag,
 					  const char *vrf_name);
 int isis_area_get(struct vty *vty, const char *area_tag);
 void isis_area_destroy(struct isis_area *area);
+void isis_filter_update(struct access_list *access);
 void print_debug(struct vty *, int, int);
 struct isis_lsp *lsp_for_arg(struct lspdb_head *head, const char *argv,
 			     struct isis *isis);
@@ -280,7 +289,7 @@ extern unsigned long debug_bfd;
 extern unsigned long debug_tx_queue;
 extern unsigned long debug_sr;
 extern unsigned long debug_ldp_sync;
-extern unsigned long debug_tilfa;
+extern unsigned long debug_lfa;
 
 #define DEBUG_ADJ_PACKETS                (1<<0)
 #define DEBUG_SNP_PACKETS                (1<<1)
@@ -296,7 +305,7 @@ extern unsigned long debug_tilfa;
 #define DEBUG_TX_QUEUE                   (1<<11)
 #define DEBUG_SR                         (1<<12)
 #define DEBUG_LDP_SYNC                   (1<<13)
-#define DEBUG_TILFA                      (1<<14)
+#define DEBUG_LFA                        (1<<14)
 
 /* Debug related macro. */
 #define IS_DEBUG_ADJ_PACKETS (debug_adj_pkt & DEBUG_ADJ_PACKETS)
@@ -313,7 +322,7 @@ extern unsigned long debug_tilfa;
 #define IS_DEBUG_TX_QUEUE (debug_tx_queue & DEBUG_TX_QUEUE)
 #define IS_DEBUG_SR (debug_sr & DEBUG_SR)
 #define IS_DEBUG_LDP_SYNC (debug_ldp_sync & DEBUG_LDP_SYNC)
-#define IS_DEBUG_TILFA (debug_tilfa & DEBUG_TILFA)
+#define IS_DEBUG_LFA (debug_lfa & DEBUG_LFA)
 
 #define lsp_debug(...)                                                         \
 	do {                                                                   \
diff --git a/tests/isisd/test_isis_spf.c b/tests/isisd/test_isis_spf.c
index 4c89a5be0..36ef93669 100644
--- a/tests/isisd/test_isis_spf.c
+++ b/tests/isisd/test_isis_spf.c
@@ -39,6 +39,7 @@
 enum test_type {
 	TEST_SPF = 1,
 	TEST_REVERSE_SPF,
+	TEST_LFA,
 	TEST_TI_LFA,
 };
 
@@ -72,6 +73,38 @@ static void test_run_spf(struct vty *vty, const struct isis_topology *topology,
 	isis_spftree_del(spftree);
 }
 
+static void test_run_lfa(struct vty *vty, const struct isis_topology *topology,
+			 const struct isis_test_node *root,
+			 struct isis_area *area, struct lspdb_head *lspdb,
+			 int level, int tree,
+			 struct lfa_protected_resource *protected_resource)
+{
+	struct isis_spftree *spftree_self;
+	uint8_t flags;
+
+	/* Run forward SPF in the root node. */
+	flags = F_SPFTREE_NO_ADJACENCIES;
+	spftree_self = isis_spftree_new(area, lspdb, root->sysid, level, tree,
+					SPF_TYPE_FORWARD, flags);
+	isis_run_spf(spftree_self);
+
+	/* Run forward SPF on all adjacent routers. */
+	isis_spf_run_neighbors(spftree_self);
+
+	/* Compute the LFA repair paths. */
+	isis_lfa_compute(area, NULL, spftree_self, protected_resource);
+
+	/* Print the SPT and the corresponding main/backup routing tables. */
+	isis_print_spftree(vty, spftree_self);
+	vty_out(vty, "Main:\n");
+	isis_print_routes(vty, spftree_self, false, false);
+	vty_out(vty, "Backup:\n");
+	isis_print_routes(vty, spftree_self, false, true);
+
+	/* Cleanup everything. */
+	isis_spftree_del(spftree_self);
+}
+
 static void test_run_ti_lfa(struct vty *vty,
 			    const struct isis_topology *topology,
 			    const struct isis_test_node *root,
@@ -120,7 +153,9 @@ static void test_run_ti_lfa(struct vty *vty,
 		vty_out(vty, " %s\n", print_sys_hostname(node->sysid));
 	vty_out(vty, "\n");
 
-	/* Print the post-convergence SPT and the correspoding routing table. */
+	/*
+	 * Print the post-convergence SPT and the corresponding routing table.
+	 */
 	isis_print_spftree(vty, spftree_pc);
 	isis_print_routes(vty, spftree_self, false, true);
 
@@ -202,6 +237,11 @@ static int test_run(struct vty *vty, const struct isis_topology *topology,
 					     &area->lspdb[level - 1], level,
 					     tree, true);
 				break;
+			case TEST_LFA:
+				test_run_lfa(vty, topology, root, area,
+					     &area->lspdb[level - 1], level,
+					     tree, &protected_resource);
+				break;
 			case TEST_TI_LFA:
 				test_run_ti_lfa(vty, topology, root, area,
 						&area->lspdb[level - 1], level,
@@ -221,10 +261,11 @@ static int test_run(struct vty *vty, const struct isis_topology *topology,
 }
 
 DEFUN(test_isis, test_isis_cmd,
-      "test isis topology (1-13) root HOSTNAME\
+      "test isis topology (1-14) root HOSTNAME\
          <\
 	   spf\
 	   |reverse-spf\
+	   |lfa system-id WORD [pseudonode-id <1-255>]\
 	   |ti-lfa system-id WORD [pseudonode-id <1-255>] [node-protection]\
 	 >\
 	 [display-lspdb] [<ipv4-only|ipv6-only>] [<level-1-only|level-2-only>]",
@@ -236,6 +277,11 @@ DEFUN(test_isis, test_isis_cmd,
       "SPF root hostname\n"
       "Normal Shortest Path First\n"
       "Reverse Shortest Path First\n"
+      "Classic LFA\n"
+      "System ID\n"
+      "System ID\n"
+      "Pseudonode-ID\n"
+      "Pseudonode-ID\n"
       "Topology Independent LFA\n"
       "System ID\n"
       "System ID\n"
@@ -281,7 +327,15 @@ DEFUN(test_isis, test_isis_cmd,
 		test_type = TEST_SPF;
 	else if (argv_find(argv, argc, "reverse-spf", &idx))
 		test_type = TEST_REVERSE_SPF;
-	else if (argv_find(argv, argc, "ti-lfa", &idx)) {
+	else if (argv_find(argv, argc, "lfa", &idx)) {
+		test_type = TEST_LFA;
+
+		fail_sysid_str = argv[idx + 2]->arg;
+		if (argv_find(argv, argc, "pseudonode-id", &idx))
+			fail_pseudonode_id =
+				strtoul(argv[idx + 1]->arg, NULL, 10);
+		protection_type = LFA_LINK_PROTECTION;
+	} else if (argv_find(argv, argc, "ti-lfa", &idx)) {
 		test_type = TEST_TI_LFA;
 
 		fail_sysid_str = argv[idx + 2]->arg;
@@ -404,7 +458,7 @@ int main(int argc, char **argv)
 	listnode_add(im->isis, isis);
 	SET_FLAG(im->options, F_ISIS_UNIT_TEST);
 	debug_spf_events |= DEBUG_SPF_EVENTS;
-	debug_tilfa |= DEBUG_TILFA;
+	debug_lfa |= DEBUG_LFA;
 	debug_events |= DEBUG_EVENTS;
 	debug_rte_events |= DEBUG_RTE_EVENTS;
 
diff --git a/tests/isisd/test_isis_spf.in b/tests/isisd/test_isis_spf.in
index 6bc5442f1..93e18124e 100644
--- a/tests/isisd/test_isis_spf.in
+++ b/tests/isisd/test_isis_spf.in
@@ -15,6 +15,22 @@ test isis topology 13 root rt1 spf ipv4-only
 test isis topology 4 root rt1 reverse-spf ipv4-only
 test isis topology 11 root rt1 reverse-spf
 
+test isis topology 1 root rt1 lfa system-id rt2
+test isis topology 2 root rt4 lfa system-id rt1 pseudonode-id 1
+test isis topology 2 root rt4 lfa system-id rt6
+test isis topology 3 root rt1 lfa system-id rt2
+test isis topology 3 root rt1 lfa system-id rt3
+test isis topology 7 root rt1 lfa system-id rt4
+test isis topology 7 root rt7 lfa system-id rt8
+test isis topology 7 root rt8 lfa system-id rt11
+test isis topology 9 root rt3 lfa system-id rt1
+test isis topology 10 root rt8 lfa system-id rt5
+test isis topology 11 root rt3 lfa system-id rt5
+test isis topology 13 root rt4 lfa system-id rt3
+test isis topology 14 root rt1 lfa system-id rt1 pseudonode-id 1
+test isis topology 14 root rt1 lfa system-id rt2
+test isis topology 14 root rt5 lfa system-id rt4
+
 test isis topology 1 root rt1 ti-lfa system-id rt2
 test isis topology 2 root rt1 ti-lfa system-id rt3
 test isis topology 2 root rt1 ti-lfa system-id rt1 pseudonode-id 1
diff --git a/tests/isisd/test_isis_spf.refout b/tests/isisd/test_isis_spf.refout
index d24176a09..dced6fb10 100644
--- a/tests/isisd/test_isis_spf.refout
+++ b/tests/isisd/test_isis_spf.refout
@@ -721,6 +721,1092 @@ IS-IS L1 IPv6 routing table:
  2001:db8::6/128  40      -          rt3      16061          

 

 test# 

+test# test isis topology 1 root rt1 lfa system-id rt2

+IS-IS paths to level-1 routers that speak IP

+Vertex               Type         Metric Next-Hop             Interface Parent

+rt1                                                                   

+10.0.255.1/32        IP internal  0                                     rt1(4)

+rt2                  TE-IS        10     rt2                  -         rt1(4)

+rt3                  TE-IS        10     rt3                  -         rt1(4)

+rt4                  TE-IS        20     rt2                  -         rt2(4)

+rt5                  TE-IS        20     rt3                  -         rt3(4)

+10.0.255.2/32        IP TE        20     rt2                  -         rt2(4)

+10.0.255.3/32        IP TE        20     rt3                  -         rt3(4)

+rt6                  TE-IS        30     rt2                  -         rt4(4)

+                                         rt3                  -         rt5(4)

+10.0.255.4/32        IP TE        30     rt2                  -         rt4(4)

+10.0.255.5/32        IP TE        30     rt3                  -         rt5(4)

+10.0.255.6/32        IP TE        40     rt2                  -         rt6(4)

+                                         rt3                  -         

+

+Main:

+IS-IS L1 IPv4 routing table:

+

+ Prefix         Metric  Interface  Nexthop  Label(s)       

+ ----------------------------------------------------------

+ 10.0.255.1/32  0       -          -        -              

+ 10.0.255.2/32  20      -          rt2      implicit-null  

+ 10.0.255.3/32  20      -          rt3      implicit-null  

+ 10.0.255.4/32  30      -          rt2      16040          

+ 10.0.255.5/32  30      -          rt3      16050          

+ 10.0.255.6/32  40      -          rt2      16060          

+                        -          rt3      16060          

+

+Backup:

+IS-IS L1 IPv4 routing table:

+

+IS-IS paths to level-1 routers that speak IPv6

+Vertex               Type         Metric Next-Hop             Interface Parent

+rt1                                                                   

+2001:db8::1/128      IP6 internal 0                                     rt1(4)

+rt2                  TE-IS        10     rt2                  -         rt1(4)

+rt3                  TE-IS        10     rt3                  -         rt1(4)

+rt4                  TE-IS        20     rt2                  -         rt2(4)

+rt5                  TE-IS        20     rt3                  -         rt3(4)

+2001:db8::2/128      IP6 internal 20     rt2                  -         rt2(4)

+2001:db8::3/128      IP6 internal 20     rt3                  -         rt3(4)

+rt6                  TE-IS        30     rt2                  -         rt4(4)

+                                         rt3                  -         rt5(4)

+2001:db8::4/128      IP6 internal 30     rt2                  -         rt4(4)

+2001:db8::5/128      IP6 internal 30     rt3                  -         rt5(4)

+2001:db8::6/128      IP6 internal 40     rt2                  -         rt6(4)

+                                         rt3                  -         

+

+Main:

+IS-IS L1 IPv6 routing table:

+

+ Prefix           Metric  Interface  Nexthop  Label(s)       

+ ------------------------------------------------------------

+ 2001:db8::1/128  0       -          -        -              

+ 2001:db8::2/128  20      -          rt2      implicit-null  

+ 2001:db8::3/128  20      -          rt3      implicit-null  

+ 2001:db8::4/128  30      -          rt2      16041          

+ 2001:db8::5/128  30      -          rt3      16051          

+ 2001:db8::6/128  40      -          rt2      16061          

+                          -          rt3      16061          

+

+Backup:

+IS-IS L1 IPv6 routing table:

+

+test# test isis topology 2 root rt4 lfa system-id rt1 pseudonode-id 1

+IS-IS paths to level-1 routers that speak IP

+Vertex               Type         Metric Next-Hop             Interface Parent

+rt4                                                                   

+10.0.255.4/32        IP internal  0                                     rt4(4)

+rt1                  TE-IS        10     rt1                  -         rt4(4)

+rt5                  TE-IS        10     rt5                  -         rt4(4)

+rt6                  TE-IS        10     rt6                  -         rt4(4)

+rt1                  pseudo_TE-IS 20     rt1                  -         rt1(4)

+                                         rt5                  -         rt5(4)

+10.0.255.1/32        IP TE        20     rt1                  -         rt1(4)

+10.0.255.5/32        IP TE        20     rt5                  -         rt5(4)

+10.0.255.6/32        IP TE        20     rt6                  -         rt6(4)

+rt2                  TE-IS        25     rt1                  -         rt1(4)

+10.0.255.2/32        IP TE        35     rt1                  -         rt2(4)

+rt3                  TE-IS        40     rt1                  -         rt1(4)

+10.0.255.3/32        IP TE        50     rt1                  -         rt3(4)

+

+Main:

+IS-IS L1 IPv4 routing table:

+

+ Prefix         Metric  Interface  Nexthop  Label(s)       

+ ----------------------------------------------------------

+ 10.0.255.1/32  20      -          rt1      implicit-null  

+ 10.0.255.2/32  35      -          rt1      16020          

+ 10.0.255.3/32  50      -          rt1      16030          

+ 10.0.255.4/32  0       -          -        -              

+ 10.0.255.5/32  20      -          rt5      implicit-null  

+ 10.0.255.6/32  20      -          rt6      implicit-null  

+

+Backup:

+IS-IS L1 IPv4 routing table:

+

+ Prefix         Metric  Interface  Nexthop  Label(s)       

+ ----------------------------------------------------------

+ 10.0.255.2/32  40      -          rt2      implicit-null  

+

+IS-IS paths to level-1 routers that speak IPv6

+Vertex               Type         Metric Next-Hop             Interface Parent

+rt4                                                                   

+2001:db8::4/128      IP6 internal 0                                     rt4(4)

+rt1                  TE-IS        10     rt1                  -         rt4(4)

+rt5                  TE-IS        10     rt5                  -         rt4(4)

+rt6                  TE-IS        10     rt6                  -         rt4(4)

+rt1                  pseudo_TE-IS 20     rt1                  -         rt1(4)

+                                         rt5                  -         rt5(4)

+2001:db8::1/128      IP6 internal 20     rt1                  -         rt1(4)

+2001:db8::5/128      IP6 internal 20     rt5                  -         rt5(4)

+2001:db8::6/128      IP6 internal 20     rt6                  -         rt6(4)

+rt2                  TE-IS        25     rt1                  -         rt1(4)

+2001:db8::2/128      IP6 internal 35     rt1                  -         rt2(4)

+rt3                  TE-IS        40     rt1                  -         rt1(4)

+2001:db8::3/128      IP6 internal 50     rt1                  -         rt3(4)

+

+Main:

+IS-IS L1 IPv6 routing table:

+

+ Prefix           Metric  Interface  Nexthop  Label(s)       

+ ------------------------------------------------------------

+ 2001:db8::1/128  20      -          rt1      implicit-null  

+ 2001:db8::2/128  35      -          rt1      16021          

+ 2001:db8::3/128  50      -          rt1      16031          

+ 2001:db8::4/128  0       -          -        -              

+ 2001:db8::5/128  20      -          rt5      implicit-null  

+ 2001:db8::6/128  20      -          rt6      implicit-null  

+

+Backup:

+IS-IS L1 IPv6 routing table:

+

+ Prefix           Metric  Interface  Nexthop  Label(s)       

+ ------------------------------------------------------------

+ 2001:db8::2/128  40      -          rt2      implicit-null  

+

+test# test isis topology 2 root rt4 lfa system-id rt6

+IS-IS paths to level-1 routers that speak IP

+Vertex               Type         Metric Next-Hop             Interface Parent

+rt4                                                                   

+10.0.255.4/32        IP internal  0                                     rt4(4)

+rt1                  TE-IS        10     rt1                  -         rt4(4)

+rt5                  TE-IS        10     rt5                  -         rt4(4)

+rt6                  TE-IS        10     rt6                  -         rt4(4)

+rt1                  pseudo_TE-IS 20     rt1                  -         rt1(4)

+                                         rt5                  -         rt5(4)

+10.0.255.1/32        IP TE        20     rt1                  -         rt1(4)

+10.0.255.5/32        IP TE        20     rt5                  -         rt5(4)

+10.0.255.6/32        IP TE        20     rt6                  -         rt6(4)

+rt2                  TE-IS        25     rt1                  -         rt1(4)

+10.0.255.2/32        IP TE        35     rt1                  -         rt2(4)

+rt3                  TE-IS        40     rt1                  -         rt1(4)

+10.0.255.3/32        IP TE        50     rt1                  -         rt3(4)

+

+Main:

+IS-IS L1 IPv4 routing table:

+

+ Prefix         Metric  Interface  Nexthop  Label(s)       

+ ----------------------------------------------------------

+ 10.0.255.1/32  20      -          rt1      implicit-null  

+ 10.0.255.2/32  35      -          rt1      16020          

+ 10.0.255.3/32  50      -          rt1      16030          

+ 10.0.255.4/32  0       -          -        -              

+ 10.0.255.5/32  20      -          rt5      implicit-null  

+ 10.0.255.6/32  20      -          rt6      implicit-null  

+

+Backup:

+IS-IS L1 IPv4 routing table:

+

+ Prefix         Metric  Interface  Nexthop  Label(s)  

+ -----------------------------------------------------

+ 10.0.255.6/32  20      -          rt5      16060     

+

+IS-IS paths to level-1 routers that speak IPv6

+Vertex               Type         Metric Next-Hop             Interface Parent

+rt4                                                                   

+2001:db8::4/128      IP6 internal 0                                     rt4(4)

+rt1                  TE-IS        10     rt1                  -         rt4(4)

+rt5                  TE-IS        10     rt5                  -         rt4(4)

+rt6                  TE-IS        10     rt6                  -         rt4(4)

+rt1                  pseudo_TE-IS 20     rt1                  -         rt1(4)

+                                         rt5                  -         rt5(4)

+2001:db8::1/128      IP6 internal 20     rt1                  -         rt1(4)

+2001:db8::5/128      IP6 internal 20     rt5                  -         rt5(4)

+2001:db8::6/128      IP6 internal 20     rt6                  -         rt6(4)

+rt2                  TE-IS        25     rt1                  -         rt1(4)

+2001:db8::2/128      IP6 internal 35     rt1                  -         rt2(4)

+rt3                  TE-IS        40     rt1                  -         rt1(4)

+2001:db8::3/128      IP6 internal 50     rt1                  -         rt3(4)

+

+Main:

+IS-IS L1 IPv6 routing table:

+

+ Prefix           Metric  Interface  Nexthop  Label(s)       

+ ------------------------------------------------------------

+ 2001:db8::1/128  20      -          rt1      implicit-null  

+ 2001:db8::2/128  35      -          rt1      16021          

+ 2001:db8::3/128  50      -          rt1      16031          

+ 2001:db8::4/128  0       -          -        -              

+ 2001:db8::5/128  20      -          rt5      implicit-null  

+ 2001:db8::6/128  20      -          rt6      implicit-null  

+

+Backup:

+IS-IS L1 IPv6 routing table:

+

+ Prefix           Metric  Interface  Nexthop  Label(s)  

+ -------------------------------------------------------

+ 2001:db8::6/128  20      -          rt5      16061     

+

+test# test isis topology 3 root rt1 lfa system-id rt2

+IS-IS paths to level-1 routers that speak IP

+Vertex               Type         Metric Next-Hop             Interface Parent

+rt1                                                                   

+10.0.255.1/32        IP internal  0                                     rt1(4)

+rt2                  TE-IS        10     rt2                  -         rt1(4)

+rt3                  TE-IS        10     rt3                  -         rt1(4)

+rt4                  TE-IS        20     rt2                  -         rt2(4)

+10.0.255.2/32        IP TE        20     rt2                  -         rt2(4)

+10.0.255.3/32        IP TE        20     rt3                  -         rt3(4)

+rt5                  TE-IS        30     rt2                  -         rt4(4)

+rt6                  TE-IS        30     rt2                  -         rt4(4)

+10.0.255.4/32        IP TE        30     rt2                  -         rt4(4)

+10.0.255.5/32        IP TE        40     rt2                  -         rt5(4)

+10.0.255.6/32        IP TE        40     rt2                  -         rt6(4)

+

+Main:

+IS-IS L1 IPv4 routing table:

+

+ Prefix         Metric  Interface  Nexthop  Label(s)       

+ ----------------------------------------------------------

+ 10.0.255.1/32  0       -          -        -              

+ 10.0.255.2/32  20      -          rt2      implicit-null  

+ 10.0.255.3/32  20      -          rt3      implicit-null  

+ 10.0.255.4/32  30      -          rt2      16040          

+ 10.0.255.5/32  40      -          rt2      16050          

+ 10.0.255.6/32  40      -          rt2      16060          

+

+Backup:

+IS-IS L1 IPv4 routing table:

+

+ Prefix         Metric  Interface  Nexthop  Label(s)  

+ -----------------------------------------------------

+ 10.0.255.2/32  20      -          rt3      16020     

+ 10.0.255.4/32  30      -          rt3      16040     

+ 10.0.255.5/32  40      -          rt3      16050     

+ 10.0.255.6/32  40      -          rt3      16060     

+

+IS-IS paths to level-1 routers that speak IPv6

+Vertex               Type         Metric Next-Hop             Interface Parent

+rt1                                                                   

+rt2                  TE-IS        10     rt2                  -         rt1(4)

+rt3                  TE-IS        10     rt3                  -         rt1(4)

+

+Main:

+IS-IS L1 IPv6 routing table:

+

+Backup:

+IS-IS L1 IPv6 routing table:

+

+test# test isis topology 3 root rt1 lfa system-id rt3

+IS-IS paths to level-1 routers that speak IP

+Vertex               Type         Metric Next-Hop             Interface Parent

+rt1                                                                   

+10.0.255.1/32        IP internal  0                                     rt1(4)

+rt2                  TE-IS        10     rt2                  -         rt1(4)

+rt3                  TE-IS        10     rt3                  -         rt1(4)

+rt4                  TE-IS        20     rt2                  -         rt2(4)

+10.0.255.2/32        IP TE        20     rt2                  -         rt2(4)

+10.0.255.3/32        IP TE        20     rt3                  -         rt3(4)

+rt5                  TE-IS        30     rt2                  -         rt4(4)

+rt6                  TE-IS        30     rt2                  -         rt4(4)

+10.0.255.4/32        IP TE        30     rt2                  -         rt4(4)

+10.0.255.5/32        IP TE        40     rt2                  -         rt5(4)

+10.0.255.6/32        IP TE        40     rt2                  -         rt6(4)

+

+Main:

+IS-IS L1 IPv4 routing table:

+

+ Prefix         Metric  Interface  Nexthop  Label(s)       

+ ----------------------------------------------------------

+ 10.0.255.1/32  0       -          -        -              

+ 10.0.255.2/32  20      -          rt2      implicit-null  

+ 10.0.255.3/32  20      -          rt3      implicit-null  

+ 10.0.255.4/32  30      -          rt2      16040          

+ 10.0.255.5/32  40      -          rt2      16050          

+ 10.0.255.6/32  40      -          rt2      16060          

+

+Backup:

+IS-IS L1 IPv4 routing table:

+

+ Prefix         Metric  Interface  Nexthop  Label(s)  

+ -----------------------------------------------------

+ 10.0.255.3/32  20      -          rt2      16030     

+

+IS-IS paths to level-1 routers that speak IPv6

+Vertex               Type         Metric Next-Hop             Interface Parent

+rt1                                                                   

+rt2                  TE-IS        10     rt2                  -         rt1(4)

+rt3                  TE-IS        10     rt3                  -         rt1(4)

+

+Main:

+IS-IS L1 IPv6 routing table:

+

+Backup:

+IS-IS L1 IPv6 routing table:

+

+test# test isis topology 7 root rt1 lfa system-id rt4

+IS-IS paths to level-1 routers that speak IP

+Vertex               Type         Metric Next-Hop             Interface Parent

+rt1                                                                   

+10.0.255.1/32        IP internal  0                                     rt1(4)

+rt4                  TE-IS        10     rt4                  -         rt1(4)

+rt5                  TE-IS        20     rt4                  -         rt4(4)

+rt7                  TE-IS        20     rt4                  -         rt4(4)

+10.0.255.4/32        IP TE        20     rt4                  -         rt4(4)

+rt2                  TE-IS        30     rt4                  -         rt5(4)

+rt6                  TE-IS        30     rt4                  -         rt5(4)

+rt8                  TE-IS        30     rt4                  -         rt5(4)

+                                                                        rt7(4)

+10.0.255.5/32        IP TE        30     rt4                  -         rt5(4)

+10.0.255.7/32        IP TE        30     rt4                  -         rt7(4)

+rt10                 TE-IS        40     rt4                  -         rt7(4)

+rt3                  TE-IS        40     rt4                  -         rt2(4)

+                                                                        rt6(4)

+rt9                  TE-IS        40     rt4                  -         rt8(4)

+rt11                 TE-IS        40     rt4                  -         rt8(4)

+10.0.255.2/32        IP TE        40     rt4                  -         rt2(4)

+10.0.255.6/32        IP TE        40     rt4                  -         rt6(4)

+10.0.255.8/32        IP TE        40     rt4                  -         rt8(4)

+rt12                 TE-IS        50     rt4                  -         rt9(4)

+                                                                        rt11(4)

+10.0.255.10/32       IP TE        50     rt4                  -         rt10(4)

+10.0.255.3/32        IP TE        50     rt4                  -         rt3(4)

+10.0.255.9/32        IP TE        50     rt4                  -         rt9(4)

+10.0.255.11/32       IP TE        50     rt4                  -         rt11(4)

+10.0.255.12/32       IP TE        60     rt4                  -         rt12(4)

+

+Main:

+IS-IS L1 IPv4 routing table:

+

+ Prefix          Metric  Interface  Nexthop  Label(s)       

+ -----------------------------------------------------------

+ 10.0.255.1/32   0       -          -        -              

+ 10.0.255.2/32   40      -          rt4      16020          

+ 10.0.255.3/32   50      -          rt4      16030          

+ 10.0.255.4/32   20      -          rt4      implicit-null  

+ 10.0.255.5/32   30      -          rt4      16050          

+ 10.0.255.6/32   40      -          rt4      16060          

+ 10.0.255.7/32   30      -          rt4      16070          

+ 10.0.255.8/32   40      -          rt4      16080          

+ 10.0.255.9/32   50      -          rt4      16090          

+ 10.0.255.10/32  50      -          rt4      16100          

+ 10.0.255.11/32  50      -          rt4      16110          

+ 10.0.255.12/32  60      -          rt4      16120          

+

+Backup:

+IS-IS L1 IPv4 routing table:

+

+ Prefix          Metric  Interface  Nexthop  Label(s)       

+ -----------------------------------------------------------

+ 10.0.255.2/32   40      -          rt2      implicit-null  

+ 10.0.255.3/32   50      -          rt2      16030          

+ 10.0.255.4/32   60      -          rt2      16040          

+ 10.0.255.5/32   50      -          rt2      16050          

+ 10.0.255.6/32   60      -          rt2      16060          

+ 10.0.255.7/32   70      -          rt2      16070          

+ 10.0.255.8/32   60      -          rt2      16080          

+ 10.0.255.9/32   70      -          rt2      16090          

+ 10.0.255.10/32  80      -          rt2      16100          

+ 10.0.255.11/32  70      -          rt2      16110          

+ 10.0.255.12/32  80      -          rt2      16120          

+

+IS-IS paths to level-1 routers that speak IPv6

+Vertex               Type         Metric Next-Hop             Interface Parent

+rt1                                                                   

+rt4                  TE-IS        10     rt4                  -         rt1(4)

+rt2                  TE-IS        40     rt2                  -         rt1(4)

+

+Main:

+IS-IS L1 IPv6 routing table:

+

+Backup:

+IS-IS L1 IPv6 routing table:

+

+test# test isis topology 7 root rt7 lfa system-id rt8

+IS-IS paths to level-1 routers that speak IP

+Vertex               Type         Metric Next-Hop             Interface Parent

+rt7                                                                   

+10.0.255.7/32        IP internal  0                                     rt7(4)

+rt4                  TE-IS        10     rt4                  -         rt7(4)

+rt8                  TE-IS        10     rt8                  -         rt7(4)

+rt10                 TE-IS        20     rt10                 -         rt7(4)

+rt1                  TE-IS        20     rt4                  -         rt4(4)

+rt5                  TE-IS        20     rt4                  -         rt4(4)

+                                         rt8                  -         rt8(4)

+rt9                  TE-IS        20     rt8                  -         rt8(4)

+rt11                 TE-IS        20     rt8                  -         rt8(4)

+10.0.255.4/32        IP TE        20     rt4                  -         rt4(4)

+10.0.255.8/32        IP TE        20     rt8                  -         rt8(4)

+rt2                  TE-IS        30     rt4                  -         rt5(4)

+                                         rt8                  -         

+rt6                  TE-IS        30     rt4                  -         rt5(4)

+                                         rt8                  -         

+rt12                 TE-IS        30     rt8                  -         rt9(4)

+                                                                        rt11(4)

+10.0.255.10/32       IP TE        30     rt10                 -         rt10(4)

+10.0.255.1/32        IP TE        30     rt4                  -         rt1(4)

+10.0.255.5/32        IP TE        30     rt4                  -         rt5(4)

+                                         rt8                  -         

+10.0.255.9/32        IP TE        30     rt8                  -         rt9(4)

+10.0.255.11/32       IP TE        30     rt8                  -         rt11(4)

+rt3                  TE-IS        40     rt4                  -         rt2(4)

+                                         rt8                  -         rt6(4)

+10.0.255.2/32        IP TE        40     rt4                  -         rt2(4)

+                                         rt8                  -         

+10.0.255.6/32        IP TE        40     rt4                  -         rt6(4)

+                                         rt8                  -         

+10.0.255.12/32       IP TE        40     rt8                  -         rt12(4)

+10.0.255.3/32        IP TE        50     rt4                  -         rt3(4)

+                                         rt8                  -         

+

+Main:

+IS-IS L1 IPv4 routing table:

+

+ Prefix          Metric  Interface  Nexthop  Label(s)       

+ -----------------------------------------------------------

+ 10.0.255.1/32   30      -          rt4      16010          

+ 10.0.255.2/32   40      -          rt4      16020          

+                         -          rt8      16020          

+ 10.0.255.3/32   50      -          rt4      16030          

+                         -          rt8      16030          

+ 10.0.255.4/32   20      -          rt4      implicit-null  

+ 10.0.255.5/32   30      -          rt4      16050          

+                         -          rt8      16050          

+ 10.0.255.6/32   40      -          rt4      16060          

+                         -          rt8      16060          

+ 10.0.255.7/32   0       -          -        -              

+ 10.0.255.8/32   20      -          rt8      implicit-null  

+ 10.0.255.9/32   30      -          rt8      16090          

+ 10.0.255.10/32  30      -          rt10     implicit-null  

+ 10.0.255.11/32  30      -          rt8      16110          

+ 10.0.255.12/32  40      -          rt8      16120          

+

+Backup:

+IS-IS L1 IPv4 routing table:

+

+ Prefix          Metric  Interface  Nexthop  Label(s)  

+ ------------------------------------------------------

+ 10.0.255.8/32   40      -          rt10     16080     

+ 10.0.255.9/32   50      -          rt10     16090     

+ 10.0.255.11/32  30      -          rt10     16110     

+ 10.0.255.12/32  40      -          rt10     16120     

+

+IS-IS paths to level-1 routers that speak IPv6

+Vertex               Type         Metric Next-Hop             Interface Parent

+rt7                                                                   

+rt4                  TE-IS        10     rt4                  -         rt7(4)

+rt8                  TE-IS        10     rt8                  -         rt7(4)

+rt10                 TE-IS        20     rt10                 -         rt7(4)

+

+Main:

+IS-IS L1 IPv6 routing table:

+

+Backup:

+IS-IS L1 IPv6 routing table:

+

+test# test isis topology 7 root rt8 lfa system-id rt11

+IS-IS paths to level-1 routers that speak IP

+Vertex               Type         Metric Next-Hop             Interface Parent

+rt8                                                                   

+10.0.255.8/32        IP internal  0                                     rt8(4)

+rt5                  TE-IS        10     rt5                  -         rt8(4)

+rt7                  TE-IS        10     rt7                  -         rt8(4)

+rt9                  TE-IS        10     rt9                  -         rt8(4)

+rt11                 TE-IS        10     rt11                 -         rt8(4)

+rt2                  TE-IS        20     rt5                  -         rt5(4)

+rt4                  TE-IS        20     rt5                  -         rt5(4)

+                                         rt7                  -         rt7(4)

+rt6                  TE-IS        20     rt5                  -         rt5(4)

+rt12                 TE-IS        20     rt9                  -         rt9(4)

+                                         rt11                 -         rt11(4)

+rt10                 TE-IS        20     rt11                 -         rt11(4)

+10.0.255.5/32        IP TE        20     rt5                  -         rt5(4)

+10.0.255.7/32        IP TE        20     rt7                  -         rt7(4)

+10.0.255.9/32        IP TE        20     rt9                  -         rt9(4)

+10.0.255.11/32       IP TE        20     rt11                 -         rt11(4)

+rt3                  TE-IS        30     rt5                  -         rt2(4)

+                                                                        rt6(4)

+rt1                  TE-IS        30     rt5                  -         rt4(4)

+                                         rt7                  -         

+10.0.255.2/32        IP TE        30     rt5                  -         rt2(4)

+10.0.255.4/32        IP TE        30     rt5                  -         rt4(4)

+                                         rt7                  -         

+10.0.255.6/32        IP TE        30     rt5                  -         rt6(4)

+10.0.255.12/32       IP TE        30     rt9                  -         rt12(4)

+                                         rt11                 -         

+10.0.255.10/32       IP TE        30     rt11                 -         rt10(4)

+10.0.255.3/32        IP TE        40     rt5                  -         rt3(4)

+10.0.255.1/32        IP TE        40     rt5                  -         rt1(4)

+                                         rt7                  -         

+

+Main:

+IS-IS L1 IPv4 routing table:

+

+ Prefix          Metric  Interface  Nexthop  Label(s)       

+ -----------------------------------------------------------

+ 10.0.255.1/32   40      -          rt5      16010          

+                         -          rt7      16010          

+ 10.0.255.2/32   30      -          rt5      16020          

+ 10.0.255.3/32   40      -          rt5      16030          

+ 10.0.255.4/32   30      -          rt5      16040          

+                         -          rt7      16040          

+ 10.0.255.5/32   20      -          rt5      implicit-null  

+ 10.0.255.6/32   30      -          rt5      16060          

+ 10.0.255.7/32   20      -          rt7      implicit-null  

+ 10.0.255.8/32   0       -          -        -              

+ 10.0.255.9/32   20      -          rt9      implicit-null  

+ 10.0.255.10/32  30      -          rt11     16100          

+ 10.0.255.11/32  20      -          rt11     implicit-null  

+ 10.0.255.12/32  30      -          rt9      16120          

+                         -          rt11     16120          

+

+Backup:

+IS-IS L1 IPv4 routing table:

+

+ Prefix          Metric  Interface  Nexthop  Label(s)  

+ ------------------------------------------------------

+ 10.0.255.10/32  30      -          rt7      16100     

+

+IS-IS paths to level-1 routers that speak IPv6

+Vertex               Type         Metric Next-Hop             Interface Parent

+rt8                                                                   

+rt5                  TE-IS        10     rt5                  -         rt8(4)

+rt7                  TE-IS        10     rt7                  -         rt8(4)

+rt9                  TE-IS        10     rt9                  -         rt8(4)

+rt11                 TE-IS        10     rt11                 -         rt8(4)

+

+Main:

+IS-IS L1 IPv6 routing table:

+

+Backup:

+IS-IS L1 IPv6 routing table:

+

+test# test isis topology 9 root rt3 lfa system-id rt1

+IS-IS paths to level-1 routers that speak IP

+Vertex               Type         Metric Next-Hop             Interface Parent

+rt3                                                                   

+10.0.255.3/32        IP internal  0                                     rt3(4)

+rt1                  TE-IS        10     rt1                  -         rt3(4)

+rt2                  TE-IS        20     rt1                  -         rt1(4)

+10.0.255.1/32        IP TE        20     rt1                  -         rt1(4)

+rt4                  TE-IS        30     rt1                  -         rt2(4)

+10.0.255.2/32        IP TE        30     rt1                  -         rt2(4)

+rt5                  TE-IS        40     rt1                  -         rt4(4)

+10.0.255.4/32        IP TE        40     rt1                  -         rt4(4)

+rt9                  TE-IS        50     rt1                  -         rt5(4)

+10.0.255.5/32        IP TE        50     rt1                  -         rt5(4)

+rt6                  TE-IS        60     rt1                  -         rt4(4)

+                                                                        rt9(4)

+rt7                  TE-IS        60     rt1                  -         rt4(4)

+                                                                        rt9(4)

+rt8                  TE-IS        60     rt1                  -         rt4(4)

+                                                                        rt9(4)

+10.0.255.9/32        IP TE        60     rt1                  -         rt9(4)

+10.0.255.6/32        IP TE        70     rt1                  -         rt6(4)

+10.0.255.7/32        IP TE        70     rt1                  -         rt7(4)

+10.0.255.8/32        IP TE        70     rt1                  -         rt8(4)

+

+Main:

+IS-IS L1 IPv4 routing table:

+

+ Prefix         Metric  Interface  Nexthop  Label(s)       

+ ----------------------------------------------------------

+ 10.0.255.1/32  20      -          rt1      implicit-null  

+ 10.0.255.2/32  30      -          rt1      16020          

+ 10.0.255.3/32  0       -          -        -              

+ 10.0.255.4/32  40      -          rt1      16040          

+ 10.0.255.5/32  50      -          rt1      16050          

+ 10.0.255.6/32  70      -          rt1      16060          

+ 10.0.255.7/32  70      -          rt1      16070          

+ 10.0.255.8/32  70      -          rt1      16080          

+ 10.0.255.9/32  60      -          rt1      16090          

+

+Backup:

+IS-IS L1 IPv4 routing table:

+

+ Prefix         Metric  Interface  Nexthop  Label(s)       

+ ----------------------------------------------------------

+ 10.0.255.1/32  120     -          rt4      16010          

+ 10.0.255.2/32  110     -          rt4      16020          

+ 10.0.255.4/32  100     -          rt4      implicit-null  

+ 10.0.255.5/32  110     -          rt4      16050          

+ 10.0.255.6/32  130     -          rt4      16060          

+ 10.0.255.7/32  130     -          rt4      16070          

+ 10.0.255.8/32  130     -          rt4      16080          

+ 10.0.255.9/32  120     -          rt4      16090          

+

+IS-IS paths to level-1 routers that speak IPv6

+Vertex               Type         Metric Next-Hop             Interface Parent

+rt3                                                                   

+2001:db8::3/128      IP6 internal 0                                     rt3(4)

+rt1                  TE-IS        10     rt1                  -         rt3(4)

+rt2                  TE-IS        20     rt1                  -         rt1(4)

+2001:db8::1/128      IP6 internal 20     rt1                  -         rt1(4)

+rt4                  TE-IS        30     rt1                  -         rt2(4)

+2001:db8::2/128      IP6 internal 30     rt1                  -         rt2(4)

+rt5                  TE-IS        40     rt1                  -         rt4(4)

+2001:db8::4/128      IP6 internal 40     rt1                  -         rt4(4)

+rt9                  TE-IS        50     rt1                  -         rt5(4)

+2001:db8::5/128      IP6 internal 50     rt1                  -         rt5(4)

+rt6                  TE-IS        60     rt1                  -         rt4(4)

+                                                                        rt9(4)

+rt7                  TE-IS        60     rt1                  -         rt4(4)

+                                                                        rt9(4)

+rt8                  TE-IS        60     rt1                  -         rt4(4)

+                                                                        rt9(4)

+2001:db8::9/128      IP6 internal 60     rt1                  -         rt9(4)

+2001:db8::6/128      IP6 internal 70     rt1                  -         rt6(4)

+2001:db8::7/128      IP6 internal 70     rt1                  -         rt7(4)

+2001:db8::8/128      IP6 internal 70     rt1                  -         rt8(4)

+

+Main:

+IS-IS L1 IPv6 routing table:

+

+ Prefix           Metric  Interface  Nexthop  Label(s)       

+ ------------------------------------------------------------

+ 2001:db8::1/128  20      -          rt1      implicit-null  

+ 2001:db8::2/128  30      -          rt1      16021          

+ 2001:db8::3/128  0       -          -        -              

+ 2001:db8::4/128  40      -          rt1      16041          

+ 2001:db8::5/128  50      -          rt1      16051          

+ 2001:db8::6/128  70      -          rt1      16061          

+ 2001:db8::7/128  70      -          rt1      16071          

+ 2001:db8::8/128  70      -          rt1      16081          

+ 2001:db8::9/128  60      -          rt1      16091          

+

+Backup:

+IS-IS L1 IPv6 routing table:

+

+ Prefix           Metric  Interface  Nexthop  Label(s)       

+ ------------------------------------------------------------

+ 2001:db8::1/128  120     -          rt4      16011          

+ 2001:db8::2/128  110     -          rt4      16021          

+ 2001:db8::4/128  100     -          rt4      implicit-null  

+ 2001:db8::5/128  110     -          rt4      16051          

+ 2001:db8::6/128  130     -          rt4      16061          

+ 2001:db8::7/128  130     -          rt4      16071          

+ 2001:db8::8/128  130     -          rt4      16081          

+ 2001:db8::9/128  120     -          rt4      16091          

+

+test# test isis topology 10 root rt8 lfa system-id rt5

+IS-IS paths to level-1 routers that speak IP

+Vertex               Type         Metric Next-Hop             Interface Parent

+rt8                                                                   

+10.0.255.8/32        IP internal  0                                     rt8(4)

+rt5                  TE-IS        10     rt5                  -         rt8(4)

+rt2                  TE-IS        20     rt5                  -         rt5(4)

+10.0.255.5/32        IP TE        20     rt5                  -         rt5(4)

+rt1                  TE-IS        30     rt5                  -         rt2(4)

+10.0.255.2/32        IP TE        30     rt5                  -         rt2(4)

+10.0.255.1/32        IP TE        40     rt5                  -         rt1(4)

+rt6                  TE-IS        50     rt6                  -         rt8(4)

+rt7                  TE-IS        50     rt7                  -         rt8(4)

+rt3                  TE-IS        50     rt5                  -         rt1(4)

+rt4                  TE-IS        50     rt5                  -         rt1(4)

+10.0.255.6/32        IP TE        60     rt6                  -         rt6(4)

+10.0.255.7/32        IP TE        60     rt7                  -         rt7(4)

+10.0.255.3/32        IP TE        60     rt5                  -         rt3(4)

+10.0.255.4/32        IP TE        60     rt5                  -         rt4(4)

+

+Main:

+IS-IS L1 IPv4 routing table:

+

+ Prefix         Metric  Interface  Nexthop  Label(s)       

+ ----------------------------------------------------------

+ 10.0.255.1/32  40      -          rt5      16010          

+ 10.0.255.2/32  30      -          rt5      16020          

+ 10.0.255.3/32  60      -          rt5      16030          

+ 10.0.255.4/32  60      -          rt5      16040          

+ 10.0.255.5/32  20      -          rt5      implicit-null  

+ 10.0.255.6/32  60      -          rt6      implicit-null  

+ 10.0.255.7/32  60      -          rt7      implicit-null  

+ 10.0.255.8/32  0       -          -        -              

+

+Backup:

+IS-IS L1 IPv4 routing table:

+

+ Prefix         Metric  Interface  Nexthop  Label(s)  

+ -----------------------------------------------------

+ 10.0.255.1/32  80      -          rt6      16010     

+                        -          rt7      16010     

+ 10.0.255.2/32  90      -          rt6      16020     

+                        -          rt7      16020     

+ 10.0.255.3/32  60      -          rt6      16030     

+                        -          rt7      16030     

+ 10.0.255.4/32  60      -          rt6      16040     

+                        -          rt7      16040     

+ 10.0.255.5/32  100     -          rt6      16050     

+                        -          rt7      16050     

+

+IS-IS paths to level-1 routers that speak IPv6

+Vertex               Type         Metric Next-Hop             Interface Parent

+rt8                                                                   

+2001:db8::8/128      IP6 internal 0                                     rt8(4)

+rt5                  TE-IS        10     rt5                  -         rt8(4)

+rt2                  TE-IS        20     rt5                  -         rt5(4)

+2001:db8::5/128      IP6 internal 20     rt5                  -         rt5(4)

+rt1                  TE-IS        30     rt5                  -         rt2(4)

+2001:db8::2/128      IP6 internal 30     rt5                  -         rt2(4)

+2001:db8::1/128      IP6 internal 40     rt5                  -         rt1(4)

+rt6                  TE-IS        50     rt6                  -         rt8(4)

+rt7                  TE-IS        50     rt7                  -         rt8(4)

+rt3                  TE-IS        50     rt5                  -         rt1(4)

+rt4                  TE-IS        50     rt5                  -         rt1(4)

+2001:db8::6/128      IP6 internal 60     rt6                  -         rt6(4)

+2001:db8::7/128      IP6 internal 60     rt7                  -         rt7(4)

+2001:db8::3/128      IP6 internal 60     rt5                  -         rt3(4)

+2001:db8::4/128      IP6 internal 60     rt5                  -         rt4(4)

+

+Main:

+IS-IS L1 IPv6 routing table:

+

+ Prefix           Metric  Interface  Nexthop  Label(s)       

+ ------------------------------------------------------------

+ 2001:db8::1/128  40      -          rt5      16011          

+ 2001:db8::2/128  30      -          rt5      16021          

+ 2001:db8::3/128  60      -          rt5      16031          

+ 2001:db8::4/128  60      -          rt5      16041          

+ 2001:db8::5/128  20      -          rt5      implicit-null  

+ 2001:db8::6/128  60      -          rt6      implicit-null  

+ 2001:db8::7/128  60      -          rt7      implicit-null  

+ 2001:db8::8/128  0       -          -        -              

+

+Backup:

+IS-IS L1 IPv6 routing table:

+

+ Prefix           Metric  Interface  Nexthop  Label(s)  

+ -------------------------------------------------------

+ 2001:db8::1/128  80      -          rt6      16011     

+                          -          rt7      16011     

+ 2001:db8::2/128  90      -          rt6      16021     

+                          -          rt7      16021     

+ 2001:db8::3/128  60      -          rt6      16031     

+                          -          rt7      16031     

+ 2001:db8::4/128  60      -          rt6      16041     

+                          -          rt7      16041     

+ 2001:db8::5/128  100     -          rt6      16051     

+                          -          rt7      16051     

+

+test# test isis topology 11 root rt3 lfa system-id rt5

+IS-IS paths to level-1 routers that speak IP

+Vertex               Type         Metric Next-Hop             Interface Parent

+rt3                                                                   

+10.0.255.3/32        IP internal  0                                     rt3(4)

+rt1                  TE-IS        10     rt1                  -         rt3(4)

+rt2                  TE-IS        10     rt2                  -         rt3(4)

+rt5                  TE-IS        10     rt5                  -         rt3(4)

+rt2                  pseudo_TE-IS 20     rt1                  -         rt1(4)

+rt4                  TE-IS        20     rt2                  -         rt2(4)

+                                         rt5                  -         rt5(4)

+rt6                  TE-IS        20     rt5                  -         rt5(4)

+10.0.255.1/32        IP TE        20     rt1                  -         rt1(4)

+10.0.255.2/32        IP TE        20     rt2                  -         rt2(4)

+10.0.255.5/32        IP TE        20     rt5                  -         rt5(4)

+10.0.255.4/32        IP TE        30     rt2                  -         rt4(4)

+                                         rt5                  -         

+10.0.255.6/32        IP TE        30     rt5                  -         rt6(4)

+

+Main:

+IS-IS L1 IPv4 routing table:

+

+ Prefix         Metric  Interface  Nexthop  Label(s)       

+ ----------------------------------------------------------

+ 10.0.255.1/32  20      -          rt1      implicit-null  

+ 10.0.255.2/32  20      -          rt2      implicit-null  

+ 10.0.255.3/32  0       -          -        -              

+ 10.0.255.4/32  30      -          rt2      16040          

+                        -          rt5      16040          

+ 10.0.255.5/32  20      -          rt5      implicit-null  

+ 10.0.255.6/32  30      -          rt5      16060          

+

+Backup:

+IS-IS L1 IPv4 routing table:

+

+ Prefix         Metric  Interface  Nexthop  Label(s)  

+ -----------------------------------------------------

+ 10.0.255.5/32  30      -          rt2      16050     

+ 10.0.255.6/32  30      -          rt2      16060     

+

+IS-IS paths to level-1 routers that speak IPv6

+Vertex               Type         Metric Next-Hop             Interface Parent

+rt3                                                                   

+2001:db8::3/128      IP6 internal 0                                     rt3(4)

+rt1                  TE-IS        10     rt1                  -         rt3(4)

+rt2                  TE-IS        10     rt2                  -         rt3(4)

+rt5                  TE-IS        10     rt5                  -         rt3(4)

+rt2                  pseudo_TE-IS 20     rt1                  -         rt1(4)

+rt4                  TE-IS        20     rt2                  -         rt2(4)

+                                         rt5                  -         rt5(4)

+rt6                  TE-IS        20     rt5                  -         rt5(4)

+2001:db8::1/128      IP6 internal 20     rt1                  -         rt1(4)

+2001:db8::2/128      IP6 internal 20     rt2                  -         rt2(4)

+2001:db8::5/128      IP6 internal 20     rt5                  -         rt5(4)

+2001:db8::4/128      IP6 internal 30     rt2                  -         rt4(4)

+                                         rt5                  -         

+2001:db8::6/128      IP6 internal 30     rt5                  -         rt6(4)

+

+Main:

+IS-IS L1 IPv6 routing table:

+

+ Prefix           Metric  Interface  Nexthop  Label(s)       

+ ------------------------------------------------------------

+ 2001:db8::1/128  20      -          rt1      implicit-null  

+ 2001:db8::2/128  20      -          rt2      implicit-null  

+ 2001:db8::3/128  0       -          -        -              

+ 2001:db8::4/128  30      -          rt2      16041          

+                          -          rt5      16041          

+ 2001:db8::5/128  20      -          rt5      implicit-null  

+ 2001:db8::6/128  30      -          rt5      16061          

+

+Backup:

+IS-IS L1 IPv6 routing table:

+

+ Prefix           Metric  Interface  Nexthop  Label(s)  

+ -------------------------------------------------------

+ 2001:db8::5/128  30      -          rt2      16051     

+ 2001:db8::6/128  30      -          rt2      16061     

+

+test# test isis topology 13 root rt4 lfa system-id rt3

+IS-IS paths to level-1 routers that speak IP

+Vertex               Type         Metric Next-Hop             Interface Parent

+rt4                                                                   

+10.0.255.4/32        IP internal  0                                     rt4(4)

+rt2                  TE-IS        10     rt2                  -         rt4(4)

+rt3                  TE-IS        10     rt3                  -         rt4(4)

+rt1                  TE-IS        20     rt2                  -         rt2(4)

+                                         rt3                  -         rt3(4)

+rt5                  TE-IS        20     rt3                  -         rt3(4)

+rt6                  TE-IS        20     rt3                  -         rt3(4)

+10.0.255.2/32        IP TE        20     rt2                  -         rt2(4)

+10.0.255.3/32        IP TE        20     rt3                  -         rt3(4)

+rt7                  TE-IS        30     rt3                  -         rt5(4)

+                                                                        rt6(4)

+10.0.255.1/32        IP TE        30     rt2                  -         rt1(4)

+                                         rt3                  -         

+10.0.255.5/32        IP TE        30     rt3                  -         rt5(4)

+10.0.255.6/32        IP TE        30     rt3                  -         rt6(4)

+10.0.255.7/32        IP TE        40     rt3                  -         rt7(4)

+

+Main:

+IS-IS L1 IPv4 routing table:

+

+ Prefix         Metric  Interface  Nexthop  Label(s)       

+ ----------------------------------------------------------

+ 10.0.255.1/32  30      -          rt2      16010          

+                        -          rt3      16010          

+ 10.0.255.2/32  20      -          rt2      implicit-null  

+ 10.0.255.3/32  20      -          rt3      implicit-null  

+ 10.0.255.4/32  0       -          -        -              

+ 10.0.255.5/32  30      -          rt3      16050          

+ 10.0.255.6/32  30      -          rt3      16060          

+ 10.0.255.7/32  40      -          rt3      16070          

+

+Backup:

+IS-IS L1 IPv4 routing table:

+

+ Prefix         Metric  Interface  Nexthop  Label(s)       

+ ----------------------------------------------------------

+ 10.0.255.3/32  110     -          rt5      16030          

+ 10.0.255.5/32  100     -          rt5      implicit-null  

+ 10.0.255.6/32  120     -          rt5      16060          

+ 10.0.255.7/32  110     -          rt5      16070          

+

+IS-IS paths to level-1 routers that speak IPv6

+Vertex               Type         Metric Next-Hop             Interface Parent

+rt4                                                                   

+rt2                  TE-IS        10     rt2                  -         rt4(4)

+rt3                  TE-IS        10     rt3                  -         rt4(4)

+rt5                  TE-IS        100    rt5                  -         rt4(4)

+

+Main:

+IS-IS L1 IPv6 routing table:

+

+Backup:

+IS-IS L1 IPv6 routing table:

+

+test# test isis topology 14 root rt1 lfa system-id rt1 pseudonode-id 1

+IS-IS paths to level-1 routers that speak IP

+Vertex               Type         Metric Next-Hop             Interface Parent

+rt1                                                                   

+10.0.255.1/32        IP internal  0                                     rt1(4)

+rt3                  TE-IS        10     rt3                  -         rt1(4)

+rt4                  TE-IS        10     rt4                  -         rt1(4)

+rt2                  TE-IS        10     rt2                  -         rt1(4)

+rt1                                                                   

+rt5                  TE-IS        20     rt4                  -         rt4(4)

+10.0.255.3/32        IP TE        20     rt3                  -         rt3(4)

+10.0.255.4/32        IP TE        20     rt4                  -         rt4(4)

+10.0.255.2/32        IP TE        20     rt2                  -         rt2(4)

+10.0.255.5/32        IP TE        30     rt4                  -         rt5(4)

+

+Main:

+IS-IS L1 IPv4 routing table:

+

+ Prefix         Metric  Interface  Nexthop  Label(s)  

+ -----------------------------------------------------

+ 10.0.255.1/32  0       -          -        -         

+ 10.0.255.2/32  20      -          rt2      -         

+ 10.0.255.3/32  20      -          rt3      -         

+ 10.0.255.4/32  20      -          rt4      -         

+ 10.0.255.5/32  30      -          rt4      -         

+

+Backup:

+IS-IS L1 IPv4 routing table:

+

+IS-IS paths to level-1 routers that speak IPv6

+Vertex               Type         Metric Next-Hop             Interface Parent

+rt1                                                                   

+2001:db8::1/128      IP6 internal 0                                     rt1(4)

+rt3                  TE-IS        10     rt3                  -         rt1(4)

+rt4                  TE-IS        10     rt4                  -         rt1(4)

+rt2                  TE-IS        10     rt2                  -         rt1(4)

+rt1                                                                   

+rt5                  TE-IS        20     rt4                  -         rt4(4)

+2001:db8::3/128      IP6 internal 20     rt3                  -         rt3(4)

+2001:db8::4/128      IP6 internal 20     rt4                  -         rt4(4)

+2001:db8::2/128      IP6 internal 20     rt2                  -         rt2(4)

+2001:db8::5/128      IP6 internal 30     rt4                  -         rt5(4)

+

+Main:

+IS-IS L1 IPv6 routing table:

+

+ Prefix           Metric  Interface  Nexthop  Label(s)  

+ -------------------------------------------------------

+ 2001:db8::1/128  0       -          -        -         

+ 2001:db8::2/128  20      -          rt2      -         

+ 2001:db8::3/128  20      -          rt3      -         

+ 2001:db8::4/128  20      -          rt4      -         

+ 2001:db8::5/128  30      -          rt4      -         

+

+Backup:

+IS-IS L1 IPv6 routing table:

+

+test# test isis topology 14 root rt1 lfa system-id rt2

+IS-IS paths to level-1 routers that speak IP

+Vertex               Type         Metric Next-Hop             Interface Parent

+rt1                                                                   

+10.0.255.1/32        IP internal  0                                     rt1(4)

+rt3                  TE-IS        10     rt3                  -         rt1(4)

+rt4                  TE-IS        10     rt4                  -         rt1(4)

+rt2                  TE-IS        10     rt2                  -         rt1(4)

+rt1                                                                   

+rt5                  TE-IS        20     rt4                  -         rt4(4)

+10.0.255.3/32        IP TE        20     rt3                  -         rt3(4)

+10.0.255.4/32        IP TE        20     rt4                  -         rt4(4)

+10.0.255.2/32        IP TE        20     rt2                  -         rt2(4)

+10.0.255.5/32        IP TE        30     rt4                  -         rt5(4)

+

+Main:

+IS-IS L1 IPv4 routing table:

+

+ Prefix         Metric  Interface  Nexthop  Label(s)  

+ -----------------------------------------------------

+ 10.0.255.1/32  0       -          -        -         

+ 10.0.255.2/32  20      -          rt2      -         

+ 10.0.255.3/32  20      -          rt3      -         

+ 10.0.255.4/32  20      -          rt4      -         

+ 10.0.255.5/32  30      -          rt4      -         

+

+Backup:

+IS-IS L1 IPv4 routing table:

+

+ Prefix         Metric  Interface  Nexthop  Label(s)  

+ -----------------------------------------------------

+ 10.0.255.2/32  20      -          rt3      -         

+

+IS-IS paths to level-1 routers that speak IPv6

+Vertex               Type         Metric Next-Hop             Interface Parent

+rt1                                                                   

+2001:db8::1/128      IP6 internal 0                                     rt1(4)

+rt3                  TE-IS        10     rt3                  -         rt1(4)

+rt4                  TE-IS        10     rt4                  -         rt1(4)

+rt2                  TE-IS        10     rt2                  -         rt1(4)

+rt1                                                                   

+rt5                  TE-IS        20     rt4                  -         rt4(4)

+2001:db8::3/128      IP6 internal 20     rt3                  -         rt3(4)

+2001:db8::4/128      IP6 internal 20     rt4                  -         rt4(4)

+2001:db8::2/128      IP6 internal 20     rt2                  -         rt2(4)

+2001:db8::5/128      IP6 internal 30     rt4                  -         rt5(4)

+

+Main:

+IS-IS L1 IPv6 routing table:

+

+ Prefix           Metric  Interface  Nexthop  Label(s)  

+ -------------------------------------------------------

+ 2001:db8::1/128  0       -          -        -         

+ 2001:db8::2/128  20      -          rt2      -         

+ 2001:db8::3/128  20      -          rt3      -         

+ 2001:db8::4/128  20      -          rt4      -         

+ 2001:db8::5/128  30      -          rt4      -         

+

+Backup:

+IS-IS L1 IPv6 routing table:

+

+ Prefix           Metric  Interface  Nexthop  Label(s)  

+ -------------------------------------------------------

+ 2001:db8::2/128  20      -          rt3      -         

+

+test# test isis topology 14 root rt5 lfa system-id rt4

+IS-IS paths to level-1 routers that speak IP

+Vertex               Type         Metric Next-Hop             Interface Parent

+rt5                                                                   

+10.0.255.5/32        IP internal  0                                     rt5(4)

+rt4                  TE-IS        10     rt4                  -         rt5(4)

+rt1                  pseudo_TE-IS 20     rt4                  -         rt4(4)

+rt1                  TE-IS        20     rt4                  -         rt1(2)

+rt3                  TE-IS        20     rt4                  -         rt1(2)

+10.0.255.4/32        IP TE        20     rt4                  -         rt4(4)

+rt2                  TE-IS        30     rt4                  -         rt1(4)

+                                                                        rt3(4)

+10.0.255.1/32        IP TE        30     rt4                  -         rt1(4)

+10.0.255.3/32        IP TE        30     rt4                  -         rt3(4)

+10.0.255.2/32        IP TE        40     rt4                  -         rt2(4)

+

+Main:

+IS-IS L1 IPv4 routing table:

+

+ Prefix         Metric  Interface  Nexthop  Label(s)  

+ -----------------------------------------------------

+ 10.0.255.1/32  30      -          rt4      -         

+ 10.0.255.2/32  40      -          rt4      -         

+ 10.0.255.3/32  30      -          rt4      -         

+ 10.0.255.4/32  20      -          rt4      -         

+ 10.0.255.5/32  0       -          -        -         

+

+Backup:

+IS-IS L1 IPv4 routing table:

+

+ Prefix         Metric  Interface  Nexthop  Label(s)  

+ -----------------------------------------------------

+ 10.0.255.1/32  60      -          rt3      -         

+ 10.0.255.2/32  60      -          rt3      -         

+ 10.0.255.3/32  50      -          rt3      -         

+ 10.0.255.4/32  60      -          rt3      -         

+

+IS-IS paths to level-1 routers that speak IPv6

+Vertex               Type         Metric Next-Hop             Interface Parent

+rt5                                                                   

+2001:db8::5/128      IP6 internal 0                                     rt5(4)

+rt4                  TE-IS        10     rt4                  -         rt5(4)

+rt1                  pseudo_TE-IS 20     rt4                  -         rt4(4)

+rt1                  TE-IS        20     rt4                  -         rt1(2)

+rt3                  TE-IS        20     rt4                  -         rt1(2)

+2001:db8::4/128      IP6 internal 20     rt4                  -         rt4(4)

+rt2                  TE-IS        30     rt4                  -         rt1(4)

+                                                                        rt3(4)

+2001:db8::1/128      IP6 internal 30     rt4                  -         rt1(4)

+2001:db8::3/128      IP6 internal 30     rt4                  -         rt3(4)

+2001:db8::2/128      IP6 internal 40     rt4                  -         rt2(4)

+

+Main:

+IS-IS L1 IPv6 routing table:

+

+ Prefix           Metric  Interface  Nexthop  Label(s)  

+ -------------------------------------------------------

+ 2001:db8::1/128  30      -          rt4      -         

+ 2001:db8::2/128  40      -          rt4      -         

+ 2001:db8::3/128  30      -          rt4      -         

+ 2001:db8::4/128  20      -          rt4      -         

+ 2001:db8::5/128  0       -          -        -         

+

+Backup:

+IS-IS L1 IPv6 routing table:

+

+ Prefix           Metric  Interface  Nexthop  Label(s)  

+ -------------------------------------------------------

+ 2001:db8::1/128  60      -          rt3      -         

+ 2001:db8::2/128  60      -          rt3      -         

+ 2001:db8::3/128  50      -          rt3      -         

+ 2001:db8::4/128  60      -          rt3      -         

+

+test# 

 test# test isis topology 1 root rt1 ti-lfa system-id rt2

 P-space (self):

  rt3

diff --git a/tests/isisd/test_topologies.c b/tests/isisd/test_topologies.c
index ee89407a7..ca103948f 100644
--- a/tests/isisd/test_topologies.c
+++ b/tests/isisd/test_topologies.c
@@ -531,6 +531,34 @@
  * |         +---------------------+         |
  * |         |                     |         |
  * +---------+                     +---------+
+
+ * Test topology 14:
+ * =================
+ *
+ * +---------+              +---------+
+ * |         |              |         |
+ * |   RT1   |              |   RT2   |
+ * |         +--------------+         |
+ * |         |              |         |
+ * +----+----+              +----+----+
+ *      |                        |
+ *      |                        |
+ *      |                        |
+ *      |                   +----+----+
+ *      |                   |         |
+ *      |                   |   RT3   |
+ *      +-------------------+         |
+ *      |                   |         |
+ *      |                   +----+----+
+ *      |                        |
+ *      |                        |50
+ *      |                        |
+ * +----+----+              +----+----+
+ * |         |              |         |
+ * |   RT4   |              |   RT5   |
+ * |         +--------------+         |
+ * |         |              |         |
+ * +---------+              +---------+
  */
 
 struct isis_topology test_topologies[] = {
@@ -3302,6 +3330,158 @@ struct isis_topology test_topologies[] = {
 		},
 	},
 	{
+		.number = 14,
+		.nodes = {
+			{
+				.hostname = "rt1",
+				.sysid = {0x00, 0x00, 0x00, 0x00, 0x00, 0x01},
+				.level = IS_LEVEL_1,
+				.router_id = "10.0.255.1",
+				.protocols = {
+					.ipv4 = true,
+					.ipv6 = true,
+				},
+				.networks = {
+					"10.0.255.1/32",
+					"2001:db8::1/128",
+				},
+				.adjacencies = {
+					{
+						.hostname = "rt1",
+						.pseudonode_id = 1,
+						.metric = 10,
+					},
+					{
+						.hostname = "rt2",
+						.metric = 10,
+					},
+				},
+			},
+			{
+				.hostname = "rt2",
+				.sysid = {0x00, 0x00, 0x00, 0x00, 0x00, 0x02},
+				.level = IS_LEVEL_1,
+				.router_id = "10.0.255.2",
+				.protocols = {
+					.ipv4 = true,
+					.ipv6 = true,
+				},
+				.networks = {
+					"10.0.255.2/32",
+					"2001:db8::2/128",
+				},
+				.adjacencies = {
+					{
+						.hostname = "rt1",
+						.metric = 20,
+					},
+					{
+						.hostname = "rt3",
+						.metric = 10,
+					},
+				},
+			},
+			{
+				.hostname = "rt3",
+				.sysid = {0x00, 0x00, 0x00, 0x00, 0x00, 0x03},
+				.level = IS_LEVEL_1,
+				.router_id = "10.0.255.3",
+				.protocols = {
+					.ipv4 = true,
+					.ipv6 = true,
+				},
+				.networks = {
+					"10.0.255.3/32",
+					"2001:db8::3/128",
+				},
+				.adjacencies = {
+					{
+						.hostname = "rt1",
+						.pseudonode_id = 1,
+						.metric = 10,
+					},
+					{
+						.hostname = "rt2",
+						.metric = 10,
+					},
+					{
+						.hostname = "rt5",
+						.metric = 50,
+					},
+				},
+			},
+			{
+				.hostname = "rt4",
+				.sysid = {0x00, 0x00, 0x00, 0x00, 0x00, 0x04},
+				.level = IS_LEVEL_1,
+				.router_id = "10.0.255.4",
+				.protocols = {
+					.ipv4 = true,
+					.ipv6 = true,
+				},
+				.networks = {
+					"10.0.255.4/32",
+					"2001:db8::4/128",
+				},
+				.adjacencies = {
+					{
+						.hostname = "rt1",
+						.pseudonode_id = 1,
+						.metric = 10,
+					},
+					{
+						.hostname = "rt5",
+						.metric = 10,
+					},
+				},
+			},
+			{
+				.hostname = "rt5",
+				.sysid = {0x00, 0x00, 0x00, 0x00, 0x00, 0x05},
+				.level = IS_LEVEL_1,
+				.router_id = "10.0.255.5",
+				.protocols = {
+					.ipv4 = true,
+					.ipv6 = true,
+				},
+				.networks = {
+					"10.0.255.5/32",
+					"2001:db8::5/128",
+				},
+				.adjacencies = {
+					{
+						.hostname = "rt4",
+						.metric = 10,
+					},
+					{
+						.hostname = "rt3",
+						.metric = 50,
+					},
+				},
+			},
+			{
+				.hostname = "rt1",
+				.sysid = {0x00, 0x00, 0x00, 0x00, 0x00, 0x01},
+				.pseudonode_id = 1,
+				.level = IS_LEVEL_1,
+				.adjacencies = {
+					{
+						.hostname = "rt1",
+						.metric = 0,
+					},
+					{
+						.hostname = "rt3",
+						.metric = 0,
+					},
+					{
+						.hostname = "rt4",
+						.metric = 0,
+					},
+				},
+			},
+		},
+	},
+	{
 		/* sentinel */
 	},
 };
diff --git a/tests/topotests/isis-lfa-topo1/__init__.py b/tests/topotests/isis-lfa-topo1/__init__.py
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/__init__.py
diff --git a/tests/topotests/isis-lfa-topo1/rt1/isisd.conf b/tests/topotests/isis-lfa-topo1/rt1/isisd.conf
new file mode 100644
index 000000000..2ad8c1253
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt1/isisd.conf
@@ -0,0 +1,52 @@
+password 1
+hostname rt1
+log file isisd.log
+!
+debug isis events
+debug isis route-events
+debug isis spf-events
+debug isis lsp-gen
+!
+interface lo
+ ipv6 router isis 1
+ isis passive
+!
+interface eth-rt2
+ ipv6 router isis 1
+ isis network point-to-point
+ isis hello-multiplier 3
+ isis fast-reroute lfa
+!
+interface eth-rt3
+ ipv6 router isis 1
+ isis network point-to-point
+ isis hello-multiplier 3
+ isis fast-reroute lfa
+!
+interface eth-rt4
+ ipv6 router isis 1
+ isis network point-to-point
+ isis hello-multiplier 3
+ isis fast-reroute lfa
+!
+interface eth-rt5
+ ipv6 router isis 1
+ isis metric 20
+ isis network point-to-point
+ isis hello-multiplier 3
+ isis fast-reroute lfa
+!
+interface eth-rt6
+ ipv6 router isis 1
+ isis network point-to-point
+ isis hello-multiplier 3
+ isis fast-reroute lfa
+!
+router isis 1
+ net 49.0000.0000.0000.0001.00
+ is-type level-1
+ lsp-gen-interval 2
+ topology ipv6-unicast
+ !fast-reroute lfa tiebreaker node-protecting index 10
+ !fast-reroute lfa tiebreaker downstream index 20
+ !fast-reroute lfa tiebreaker lowest-backup-metric index 30
diff --git a/tests/topotests/isis-lfa-topo1/rt1/step1/show_ipv6_route.ref b/tests/topotests/isis-lfa-topo1/rt1/step1/show_ipv6_route.ref
new file mode 100644
index 000000000..10c61d53e
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt1/step1/show_ipv6_route.ref
@@ -0,0 +1,236 @@
+{
+  "2001:db8:1000::2\/128":[
+    {
+      "prefix":"2001:db8:1000::2\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":20,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt2",
+          "active":true,
+          "backupIndex":[
+            0,
+            1,
+            2
+          ]
+        }
+      ],
+      "backupNexthops":[
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt3",
+          "active":true
+        },
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt5",
+          "active":true
+        },
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt6",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "2001:db8:1000::3\/128":[
+    {
+      "prefix":"2001:db8:1000::3\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":20,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt3",
+          "active":true,
+          "backupIndex":[
+            0,
+            1
+          ]
+        }
+      ],
+      "backupNexthops":[
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt2",
+          "active":true
+        },
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt5",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "2001:db8:1000::4\/128":[
+    {
+      "prefix":"2001:db8:1000::4\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":20,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt4",
+          "active":true,
+          "backupIndex":[
+            0
+          ]
+        }
+      ],
+      "backupNexthops":[
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt5",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "2001:db8:1000::5\/128":[
+    {
+      "prefix":"2001:db8:1000::5\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":30,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt5",
+          "active":true,
+          "backupIndex":[
+            0,
+            1,
+            2,
+            3
+          ]
+        }
+      ],
+      "backupNexthops":[
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt2",
+          "active":true
+        },
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt3",
+          "active":true
+        },
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt4",
+          "active":true
+        },
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt6",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "2001:db8:1000::6\/128":[
+    {
+      "prefix":"2001:db8:1000::6\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":20,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt6",
+          "active":true,
+          "backupIndex":[
+            0,
+            1
+          ]
+        }
+      ],
+      "backupNexthops":[
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt2",
+          "active":true
+        },
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt5",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "2001:db8:1000::7\/128":[
+    {
+      "prefix":"2001:db8:1000::7\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":25,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt2",
+          "active":true,
+          "backupIndex":[
+            0,
+            1,
+            2,
+            3
+          ]
+        }
+      ],
+      "backupNexthops":[
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt3",
+          "active":true
+        },
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt4",
+          "active":true
+        },
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt5",
+          "active":true
+        },
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt6",
+          "active":true
+        }
+      ]
+    }
+  ]
+}
diff --git a/tests/topotests/isis-lfa-topo1/rt1/step1/show_yang_interface_isis_adjacencies.ref b/tests/topotests/isis-lfa-topo1/rt1/step1/show_yang_interface_isis_adjacencies.ref
new file mode 100644
index 000000000..d8a7c5a9c
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt1/step1/show_yang_interface_isis_adjacencies.ref
@@ -0,0 +1,101 @@
+{
+  "frr-interface:lib": {
+    "interface": [
+      {
+        "name": "eth-rt2",
+        "vrf": "default",
+        "state": {
+          "frr-isisd:isis": {
+            "adjacencies": {
+              "adjacency": [
+                {
+                  "neighbor-sys-type": "level-1",
+                  "neighbor-sysid": "0000.0000.0002",
+                  "hold-timer": 9,
+                  "neighbor-priority": 0,
+                  "state": "up"
+                }
+              ]
+            }
+          }
+        }
+      },
+      {
+        "name": "eth-rt3",
+        "vrf": "default",
+        "state": {
+          "frr-isisd:isis": {
+            "adjacencies": {
+              "adjacency": [
+                {
+                  "neighbor-sys-type": "level-1",
+                  "neighbor-sysid": "0000.0000.0003",
+                  "hold-timer": 9,
+                  "neighbor-priority": 0,
+                  "state": "up"
+                }
+              ]
+            }
+          }
+        }
+      },
+      {
+        "name": "eth-rt4",
+        "vrf": "default",
+        "state": {
+          "frr-isisd:isis": {
+            "adjacencies": {
+              "adjacency": [
+                {
+                  "neighbor-sys-type": "level-1",
+                  "neighbor-sysid": "0000.0000.0004",
+                  "hold-timer": 9,
+                  "neighbor-priority": 0,
+                  "state": "up"
+                }
+              ]
+            }
+          }
+        }
+      },
+      {
+        "name": "eth-rt5",
+        "vrf": "default",
+        "state": {
+          "frr-isisd:isis": {
+            "adjacencies": {
+              "adjacency": [
+                {
+                  "neighbor-sys-type": "level-1",
+                  "neighbor-sysid": "0000.0000.0005",
+                  "hold-timer": 9,
+                  "neighbor-priority": 0,
+                  "state": "up"
+                }
+              ]
+            }
+          }
+        }
+      },
+      {
+        "name": "eth-rt6",
+        "vrf": "default",
+        "state": {
+          "frr-isisd:isis": {
+            "adjacencies": {
+              "adjacency": [
+                {
+                  "neighbor-sys-type": "level-1",
+                  "neighbor-sysid": "0000.0000.0006",
+                  "hold-timer": 9,
+                  "neighbor-priority": 0,
+                  "state": "up"
+                }
+              ]
+            }
+          }
+        }
+      }
+    ]
+  }
+}
diff --git a/tests/topotests/isis-lfa-topo1/rt1/step10/show_ipv6_route.ref.diff b/tests/topotests/isis-lfa-topo1/rt1/step10/show_ipv6_route.ref.diff
new file mode 100644
index 000000000..d626cdca0
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt1/step10/show_ipv6_route.ref.diff
@@ -0,0 +1,46 @@
+--- a/rt1/step9/show_ipv6_route.ref
++++ b/rt1/step10/show_ipv6_route.ref
+@@ -16,7 +16,8 @@
+           "active":true,
+           "backupIndex":[
+             0,
+-            1
++            1,
++            2
+           ]
+         }
+       ],
+@@ -30,6 +31,11 @@
+           "afi":"ipv6",
+           "interfaceName":"eth-rt5",
+           "active":true
++        },
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt6",
++          "active":true
+         }
+       ]
+     }
+@@ -198,7 +204,8 @@
+           "backupIndex":[
+             0,
+             1,
+-            2
++            2,
++            3
+           ]
+         }
+       ],
+@@ -217,6 +224,11 @@
+           "afi":"ipv6",
+           "interfaceName":"eth-rt5",
+           "active":true
++        },
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt6",
++          "active":true
+         }
+       ]
+     }
diff --git a/tests/topotests/isis-lfa-topo1/rt1/step11/show_ipv6_route.ref.diff b/tests/topotests/isis-lfa-topo1/rt1/step11/show_ipv6_route.ref.diff
new file mode 100644
index 000000000..f7f99c276
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt1/step11/show_ipv6_route.ref.diff
@@ -0,0 +1,23 @@
+--- a/rt1/step10/show_ipv6_route.ref
++++ b/rt1/step11/show_ipv6_route.ref
+@@ -204,19 +204,13 @@
+           "backupIndex":[
+             0,
+             1,
+-            2,
+-            3
++            2
+           ]
+         }
+       ],
+       "backupNexthops":[
+         {
+           "afi":"ipv6",
+-          "interfaceName":"eth-rt3",
+-          "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+           "interfaceName":"eth-rt4",
+           "active":true
+         },
diff --git a/tests/topotests/isis-lfa-topo1/rt1/step12/show_ipv6_route.ref.diff b/tests/topotests/isis-lfa-topo1/rt1/step12/show_ipv6_route.ref.diff
new file mode 100644
index 000000000..3b767f1bf
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt1/step12/show_ipv6_route.ref.diff
@@ -0,0 +1,107 @@
+--- a/rt1/step11/show_ipv6_route.ref
++++ b/rt1/step12/show_ipv6_route.ref
+@@ -15,9 +15,7 @@
+           "interfaceName":"eth-rt2",
+           "active":true,
+           "backupIndex":[
+-            0,
+-            1,
+-            2
++            0
+           ]
+         }
+       ],
+@@ -26,16 +24,6 @@
+           "afi":"ipv6",
+           "interfaceName":"eth-rt3",
+           "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt5",
+-          "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt6",
+-          "active":true
+         }
+       ]
+     }
+@@ -56,8 +44,7 @@
+           "interfaceName":"eth-rt3",
+           "active":true,
+           "backupIndex":[
+-            0,
+-            1
++            0
+           ]
+         }
+       ],
+@@ -66,11 +53,6 @@
+           "afi":"ipv6",
+           "interfaceName":"eth-rt2",
+           "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt5",
+-          "active":true
+         }
+       ]
+     }
+@@ -120,10 +102,7 @@
+           "interfaceName":"eth-rt5",
+           "active":true,
+           "backupIndex":[
+-            0,
+-            1,
+-            2,
+-            3
++            0
+           ]
+         }
+       ],
+@@ -132,21 +111,6 @@
+           "afi":"ipv6",
+           "interfaceName":"eth-rt2",
+           "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt3",
+-          "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt4",
+-          "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt6",
+-          "active":true
+         }
+       ]
+     }
+@@ -203,19 +167,13 @@
+           "active":true,
+           "backupIndex":[
+             0,
+-            1,
+-            2
++            1
+           ]
+         }
+       ],
+       "backupNexthops":[
+         {
+           "afi":"ipv6",
+-          "interfaceName":"eth-rt4",
+-          "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+           "interfaceName":"eth-rt5",
+           "active":true
+         },
diff --git a/tests/topotests/isis-lfa-topo1/rt1/step13/show_ipv6_route.ref.diff b/tests/topotests/isis-lfa-topo1/rt1/step13/show_ipv6_route.ref.diff
new file mode 100644
index 000000000..504af5ac5
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt1/step13/show_ipv6_route.ref.diff
@@ -0,0 +1,45 @@
+--- a/rt1/step12/show_ipv6_route.ref
++++ b/rt1/step13/show_ipv6_route.ref
+@@ -131,8 +131,7 @@
+           "interfaceName":"eth-rt6",
+           "active":true,
+           "backupIndex":[
+-            0,
+-            1
++            0
+           ]
+         }
+       ],
+@@ -141,11 +140,6 @@
+           "afi":"ipv6",
+           "interfaceName":"eth-rt2",
+           "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt5",
+-          "active":true
+         }
+       ]
+     }
+@@ -166,19 +160,13 @@
+           "interfaceName":"eth-rt2",
+           "active":true,
+           "backupIndex":[
+-            0,
+-            1
++            0
+           ]
+         }
+       ],
+       "backupNexthops":[
+         {
+           "afi":"ipv6",
+-          "interfaceName":"eth-rt5",
+-          "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+           "interfaceName":"eth-rt6",
+           "active":true
+         }
diff --git a/tests/topotests/isis-lfa-topo1/rt1/step2/show_ipv6_route.ref.diff b/tests/topotests/isis-lfa-topo1/rt1/step2/show_ipv6_route.ref.diff
new file mode 100644
index 000000000..efc56d983
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt1/step2/show_ipv6_route.ref.diff
@@ -0,0 +1,164 @@
+--- a/rt1/step1/show_ipv6_route.ref
++++ b/rt1/step2/show_ipv6_route.ref
+@@ -13,28 +13,6 @@
+           "fib":true,
+           "afi":"ipv6",
+           "interfaceName":"eth-rt2",
+-          "active":true,
+-          "backupIndex":[
+-            0,
+-            1,
+-            2
+-          ]
+-        }
+-      ],
+-      "backupNexthops":[
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt3",
+-          "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt5",
+-          "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt6",
+           "active":true
+         }
+       ]
+@@ -54,22 +32,6 @@
+           "fib":true,
+           "afi":"ipv6",
+           "interfaceName":"eth-rt3",
+-          "active":true,
+-          "backupIndex":[
+-            0,
+-            1
+-          ]
+-        }
+-      ],
+-      "backupNexthops":[
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt2",
+-          "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt5",
+           "active":true
+         }
+       ]
+@@ -89,16 +51,6 @@
+           "fib":true,
+           "afi":"ipv6",
+           "interfaceName":"eth-rt4",
+-          "active":true,
+-          "backupIndex":[
+-            0
+-          ]
+-        }
+-      ],
+-      "backupNexthops":[
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt5",
+           "active":true
+         }
+       ]
+@@ -118,34 +70,6 @@
+           "fib":true,
+           "afi":"ipv6",
+           "interfaceName":"eth-rt5",
+-          "active":true,
+-          "backupIndex":[
+-            0,
+-            1,
+-            2,
+-            3
+-          ]
+-        }
+-      ],
+-      "backupNexthops":[
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt2",
+-          "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt3",
+-          "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt4",
+-          "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt6",
+           "active":true
+         }
+       ]
+@@ -165,22 +89,6 @@
+           "fib":true,
+           "afi":"ipv6",
+           "interfaceName":"eth-rt6",
+-          "active":true,
+-          "backupIndex":[
+-            0,
+-            1
+-          ]
+-        }
+-      ],
+-      "backupNexthops":[
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt2",
+-          "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt5",
+           "active":true
+         }
+       ]
+@@ -200,34 +108,6 @@
+           "fib":true,
+           "afi":"ipv6",
+           "interfaceName":"eth-rt2",
+-          "active":true,
+-          "backupIndex":[
+-            0,
+-            1,
+-            2,
+-            3
+-          ]
+-        }
+-      ],
+-      "backupNexthops":[
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt3",
+-          "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt4",
+-          "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt5",
+-          "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt6",
+           "active":true
+         }
+       ]
diff --git a/tests/topotests/isis-lfa-topo1/rt1/step3/show_ipv6_route.ref.diff b/tests/topotests/isis-lfa-topo1/rt1/step3/show_ipv6_route.ref.diff
new file mode 100644
index 000000000..cafbe490b
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt1/step3/show_ipv6_route.ref.diff
@@ -0,0 +1,164 @@
+--- a/rt1/step2/show_ipv6_route.ref
++++ b/rt1/step3/show_ipv6_route.ref
+@@ -13,6 +13,28 @@
+           "fib":true,
+           "afi":"ipv6",
+           "interfaceName":"eth-rt2",
++          "active":true,
++          "backupIndex":[
++            0,
++            1,
++            2
++          ]
++        }
++      ],
++      "backupNexthops":[
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt3",
++          "active":true
++        },
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt5",
++          "active":true
++        },
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt6",
+           "active":true
+         }
+       ]
+@@ -32,6 +54,22 @@
+           "fib":true,
+           "afi":"ipv6",
+           "interfaceName":"eth-rt3",
++          "active":true,
++          "backupIndex":[
++            0,
++            1
++          ]
++        }
++      ],
++      "backupNexthops":[
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt2",
++          "active":true
++        },
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt5",
+           "active":true
+         }
+       ]
+@@ -51,6 +89,16 @@
+           "fib":true,
+           "afi":"ipv6",
+           "interfaceName":"eth-rt4",
++          "active":true,
++          "backupIndex":[
++            0
++          ]
++        }
++      ],
++      "backupNexthops":[
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt5",
+           "active":true
+         }
+       ]
+@@ -70,6 +118,34 @@
+           "fib":true,
+           "afi":"ipv6",
+           "interfaceName":"eth-rt5",
++          "active":true,
++          "backupIndex":[
++            0,
++            1,
++            2,
++            3
++          ]
++        }
++      ],
++      "backupNexthops":[
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt2",
++          "active":true
++        },
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt3",
++          "active":true
++        },
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt4",
++          "active":true
++        },
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt6",
+           "active":true
+         }
+       ]
+@@ -89,6 +165,22 @@
+           "fib":true,
+           "afi":"ipv6",
+           "interfaceName":"eth-rt6",
++          "active":true,
++          "backupIndex":[
++            0,
++            1
++          ]
++        }
++      ],
++      "backupNexthops":[
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt2",
++          "active":true
++        },
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt5",
+           "active":true
+         }
+       ]
+@@ -108,6 +200,34 @@
+           "fib":true,
+           "afi":"ipv6",
+           "interfaceName":"eth-rt2",
++          "active":true,
++          "backupIndex":[
++            0,
++            1,
++            2,
++            3
++          ]
++        }
++      ],
++      "backupNexthops":[
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt3",
++          "active":true
++        },
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt4",
++          "active":true
++        },
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt5",
++          "active":true
++        },
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt6",
+           "active":true
+         }
+       ]
diff --git a/tests/topotests/isis-lfa-topo1/rt1/step4/show_ipv6_route.ref.diff b/tests/topotests/isis-lfa-topo1/rt1/step4/show_ipv6_route.ref.diff
new file mode 100644
index 000000000..47d8334a0
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt1/step4/show_ipv6_route.ref.diff
@@ -0,0 +1,142 @@
+--- a/rt1/step3/show_ipv6_route.ref
++++ b/rt1/step4/show_ipv6_route.ref
+@@ -15,9 +15,7 @@
+           "interfaceName":"eth-rt2",
+           "active":true,
+           "backupIndex":[
+-            0,
+-            1,
+-            2
++            0
+           ]
+         }
+       ],
+@@ -26,16 +24,6 @@
+           "afi":"ipv6",
+           "interfaceName":"eth-rt3",
+           "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt5",
+-          "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt6",
+-          "active":true
+         }
+       ]
+     }
+@@ -56,8 +44,7 @@
+           "interfaceName":"eth-rt3",
+           "active":true,
+           "backupIndex":[
+-            0,
+-            1
++            0
+           ]
+         }
+       ],
+@@ -66,11 +53,6 @@
+           "afi":"ipv6",
+           "interfaceName":"eth-rt2",
+           "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt5",
+-          "active":true
+         }
+       ]
+     }
+@@ -120,10 +102,7 @@
+           "interfaceName":"eth-rt5",
+           "active":true,
+           "backupIndex":[
+-            0,
+-            1,
+-            2,
+-            3
++            0
+           ]
+         }
+       ],
+@@ -132,21 +111,6 @@
+           "afi":"ipv6",
+           "interfaceName":"eth-rt2",
+           "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt3",
+-          "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt4",
+-          "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt6",
+-          "active":true
+         }
+       ]
+     }
+@@ -167,8 +131,7 @@
+           "interfaceName":"eth-rt6",
+           "active":true,
+           "backupIndex":[
+-            0,
+-            1
++            0
+           ]
+         }
+       ],
+@@ -177,11 +140,6 @@
+           "afi":"ipv6",
+           "interfaceName":"eth-rt2",
+           "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt5",
+-          "active":true
+         }
+       ]
+     }
+@@ -202,10 +160,7 @@
+           "interfaceName":"eth-rt2",
+           "active":true,
+           "backupIndex":[
+-            0,
+-            1,
+-            2,
+-            3
++            0
+           ]
+         }
+       ],
+@@ -214,21 +169,6 @@
+           "afi":"ipv6",
+           "interfaceName":"eth-rt3",
+           "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt4",
+-          "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt5",
+-          "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt6",
+-          "active":true
+         }
+       ]
+     }
diff --git a/tests/topotests/isis-lfa-topo1/rt1/step5/show_ipv6_route.ref.diff b/tests/topotests/isis-lfa-topo1/rt1/step5/show_ipv6_route.ref.diff
new file mode 100644
index 000000000..b6a342df8
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt1/step5/show_ipv6_route.ref.diff
@@ -0,0 +1,142 @@
+--- a/rt1/step4/show_ipv6_route.ref
++++ b/rt1/step5/show_ipv6_route.ref
+@@ -15,7 +15,9 @@
+           "interfaceName":"eth-rt2",
+           "active":true,
+           "backupIndex":[
+-            0
++            0,
++            1,
++            2
+           ]
+         }
+       ],
+@@ -24,6 +26,16 @@
+           "afi":"ipv6",
+           "interfaceName":"eth-rt3",
+           "active":true
++        },
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt5",
++          "active":true
++        },
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt6",
++          "active":true
+         }
+       ]
+     }
+@@ -44,7 +56,8 @@
+           "interfaceName":"eth-rt3",
+           "active":true,
+           "backupIndex":[
+-            0
++            0,
++            1
+           ]
+         }
+       ],
+@@ -53,6 +66,11 @@
+           "afi":"ipv6",
+           "interfaceName":"eth-rt2",
+           "active":true
++        },
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt5",
++          "active":true
+         }
+       ]
+     }
+@@ -102,7 +120,10 @@
+           "interfaceName":"eth-rt5",
+           "active":true,
+           "backupIndex":[
+-            0
++            0,
++            1,
++            2,
++            3
+           ]
+         }
+       ],
+@@ -111,6 +132,21 @@
+           "afi":"ipv6",
+           "interfaceName":"eth-rt2",
+           "active":true
++        },
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt3",
++          "active":true
++        },
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt4",
++          "active":true
++        },
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt6",
++          "active":true
+         }
+       ]
+     }
+@@ -131,7 +167,8 @@
+           "interfaceName":"eth-rt6",
+           "active":true,
+           "backupIndex":[
+-            0
++            0,
++            1
+           ]
+         }
+       ],
+@@ -140,6 +177,11 @@
+           "afi":"ipv6",
+           "interfaceName":"eth-rt2",
+           "active":true
++        },
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt5",
++          "active":true
+         }
+       ]
+     }
+@@ -160,7 +202,10 @@
+           "interfaceName":"eth-rt2",
+           "active":true,
+           "backupIndex":[
+-            0
++            0,
++            1,
++            2,
++            3
+           ]
+         }
+       ],
+@@ -169,6 +214,21 @@
+           "afi":"ipv6",
+           "interfaceName":"eth-rt3",
+           "active":true
++        },
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt4",
++          "active":true
++        },
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt5",
++          "active":true
++        },
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt6",
++          "active":true
+         }
+       ]
+     }
diff --git a/tests/topotests/isis-lfa-topo1/rt1/step6/show_ipv6_route.ref.diff b/tests/topotests/isis-lfa-topo1/rt1/step6/show_ipv6_route.ref.diff
new file mode 100644
index 000000000..fafa2999d
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt1/step6/show_ipv6_route.ref.diff
@@ -0,0 +1,164 @@
+--- a/rt1/step5/show_ipv6_route.ref
++++ b/rt1/step6/show_ipv6_route.ref
+@@ -13,28 +13,6 @@
+           "fib":true,
+           "afi":"ipv6",
+           "interfaceName":"eth-rt2",
+-          "active":true,
+-          "backupIndex":[
+-            0,
+-            1,
+-            2
+-          ]
+-        }
+-      ],
+-      "backupNexthops":[
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt3",
+-          "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt5",
+-          "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt6",
+           "active":true
+         }
+       ]
+@@ -54,22 +32,6 @@
+           "fib":true,
+           "afi":"ipv6",
+           "interfaceName":"eth-rt3",
+-          "active":true,
+-          "backupIndex":[
+-            0,
+-            1
+-          ]
+-        }
+-      ],
+-      "backupNexthops":[
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt2",
+-          "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt5",
+           "active":true
+         }
+       ]
+@@ -89,16 +51,6 @@
+           "fib":true,
+           "afi":"ipv6",
+           "interfaceName":"eth-rt4",
+-          "active":true,
+-          "backupIndex":[
+-            0
+-          ]
+-        }
+-      ],
+-      "backupNexthops":[
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt5",
+           "active":true
+         }
+       ]
+@@ -118,34 +70,6 @@
+           "fib":true,
+           "afi":"ipv6",
+           "interfaceName":"eth-rt5",
+-          "active":true,
+-          "backupIndex":[
+-            0,
+-            1,
+-            2,
+-            3
+-          ]
+-        }
+-      ],
+-      "backupNexthops":[
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt2",
+-          "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt3",
+-          "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt4",
+-          "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt6",
+           "active":true
+         }
+       ]
+@@ -165,22 +89,6 @@
+           "fib":true,
+           "afi":"ipv6",
+           "interfaceName":"eth-rt6",
+-          "active":true,
+-          "backupIndex":[
+-            0,
+-            1
+-          ]
+-        }
+-      ],
+-      "backupNexthops":[
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt2",
+-          "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt5",
+           "active":true
+         }
+       ]
+@@ -200,34 +108,6 @@
+           "fib":true,
+           "afi":"ipv6",
+           "interfaceName":"eth-rt2",
+-          "active":true,
+-          "backupIndex":[
+-            0,
+-            1,
+-            2,
+-            3
+-          ]
+-        }
+-      ],
+-      "backupNexthops":[
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt3",
+-          "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt4",
+-          "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt5",
+-          "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt6",
+           "active":true
+         }
+       ]
diff --git a/tests/topotests/isis-lfa-topo1/rt1/step7/show_ipv6_route.ref.diff b/tests/topotests/isis-lfa-topo1/rt1/step7/show_ipv6_route.ref.diff
new file mode 100644
index 000000000..1803e2cf5
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt1/step7/show_ipv6_route.ref.diff
@@ -0,0 +1,37 @@
+--- a/rt1/step6/show_ipv6_route.ref
++++ b/rt1/step7/show_ipv6_route.ref
+@@ -108,6 +108,34 @@
+           "fib":true,
+           "afi":"ipv6",
+           "interfaceName":"eth-rt2",
++          "active":true,
++          "backupIndex":[
++            0,
++            1,
++            2,
++            3
++          ]
++        }
++      ],
++      "backupNexthops":[
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt3",
++          "active":true
++        },
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt4",
++          "active":true
++        },
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt5",
++          "active":true
++        },
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt6",
+           "active":true
+         }
+       ]
diff --git a/tests/topotests/isis-lfa-topo1/rt1/step8/show_ipv6_route.ref.diff b/tests/topotests/isis-lfa-topo1/rt1/step8/show_ipv6_route.ref.diff
new file mode 100644
index 000000000..306f72534
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt1/step8/show_ipv6_route.ref.diff
@@ -0,0 +1,129 @@
+--- a/rt1/step7/show_ipv6_route.ref
++++ b/rt1/step8/show_ipv6_route.ref
+@@ -13,6 +13,28 @@
+           "fib":true,
+           "afi":"ipv6",
+           "interfaceName":"eth-rt2",
++          "active":true,
++          "backupIndex":[
++            0,
++            1,
++            2
++          ]
++        }
++      ],
++      "backupNexthops":[
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt3",
++          "active":true
++        },
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt5",
++          "active":true
++        },
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt6",
+           "active":true
+         }
+       ]
+@@ -32,6 +54,22 @@
+           "fib":true,
+           "afi":"ipv6",
+           "interfaceName":"eth-rt3",
++          "active":true,
++          "backupIndex":[
++            0,
++            1
++          ]
++        }
++      ],
++      "backupNexthops":[
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt2",
++          "active":true
++        },
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt5",
+           "active":true
+         }
+       ]
+@@ -51,6 +89,16 @@
+           "fib":true,
+           "afi":"ipv6",
+           "interfaceName":"eth-rt4",
++          "active":true,
++          "backupIndex":[
++            0
++          ]
++        }
++      ],
++      "backupNexthops":[
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt5",
+           "active":true
+         }
+       ]
+@@ -70,6 +118,34 @@
+           "fib":true,
+           "afi":"ipv6",
+           "interfaceName":"eth-rt5",
++          "active":true,
++          "backupIndex":[
++            0,
++            1,
++            2,
++            3
++          ]
++        }
++      ],
++      "backupNexthops":[
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt2",
++          "active":true
++        },
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt3",
++          "active":true
++        },
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt4",
++          "active":true
++        },
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt6",
+           "active":true
+         }
+       ]
+@@ -89,6 +165,22 @@
+           "fib":true,
+           "afi":"ipv6",
+           "interfaceName":"eth-rt6",
++          "active":true,
++          "backupIndex":[
++            0,
++            1
++          ]
++        }
++      ],
++      "backupNexthops":[
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt2",
++          "active":true
++        },
++        {
++          "afi":"ipv6",
++          "interfaceName":"eth-rt5",
+           "active":true
+         }
+       ]
diff --git a/tests/topotests/isis-lfa-topo1/rt1/step9/show_ipv6_route.ref.diff b/tests/topotests/isis-lfa-topo1/rt1/step9/show_ipv6_route.ref.diff
new file mode 100644
index 000000000..3ffab46ee
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt1/step9/show_ipv6_route.ref.diff
@@ -0,0 +1,46 @@
+--- a/rt1/step8/show_ipv6_route.ref
++++ b/rt1/step9/show_ipv6_route.ref
+@@ -16,8 +16,7 @@
+           "active":true,
+           "backupIndex":[
+             0,
+-            1,
+-            2
++            1
+           ]
+         }
+       ],
+@@ -31,11 +30,6 @@
+           "afi":"ipv6",
+           "interfaceName":"eth-rt5",
+           "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt6",
+-          "active":true
+         }
+       ]
+     }
+@@ -204,8 +198,7 @@
+           "backupIndex":[
+             0,
+             1,
+-            2,
+-            3
++            2
+           ]
+         }
+       ],
+@@ -224,11 +217,6 @@
+           "afi":"ipv6",
+           "interfaceName":"eth-rt5",
+           "active":true
+-        },
+-        {
+-          "afi":"ipv6",
+-          "interfaceName":"eth-rt6",
+-          "active":true
+         }
+       ]
+     }
diff --git a/tests/topotests/isis-lfa-topo1/rt1/zebra.conf b/tests/topotests/isis-lfa-topo1/rt1/zebra.conf
new file mode 100644
index 000000000..317f1031d
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt1/zebra.conf
@@ -0,0 +1,16 @@
+log file zebra.log
+!
+hostname rt1
+!
+debug zebra kernel
+debug zebra packet
+debug zebra mpls
+!
+interface lo
+ ip address 1.1.1.1/32
+ ipv6 address 2001:db8:1000::1/128
+!
+ip forwarding
+!
+line vty
+!
diff --git a/tests/topotests/isis-lfa-topo1/rt2/isisd.conf b/tests/topotests/isis-lfa-topo1/rt2/isisd.conf
new file mode 100644
index 000000000..39ff2570d
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt2/isisd.conf
@@ -0,0 +1,39 @@
+password 1
+hostname rt2
+log file isisd.log
+!
+debug isis events
+debug isis route-events
+debug isis spf-events
+debug isis lsp-gen
+!
+interface lo
+ ipv6 router isis 1
+ isis passive
+!
+interface eth-rt1
+ ipv6 router isis 1
+ isis network point-to-point
+ isis hello-multiplier 3
+ isis fast-reroute lfa
+!
+interface eth-rt3
+ ipv6 router isis 1
+ isis metric 5
+ isis network point-to-point
+ isis hello-multiplier 3
+ isis fast-reroute lfa
+!
+interface eth-rt7
+ ipv6 router isis 1
+ isis metric 5
+ isis network point-to-point
+ isis hello-multiplier 3
+ isis fast-reroute lfa
+!
+router isis 1
+ net 49.0000.0000.0000.0002.00
+ is-type level-1
+ lsp-gen-interval 2
+ topology ipv6-unicast
+!
diff --git a/tests/topotests/isis-lfa-topo1/rt2/step1/show_ipv6_route.ref b/tests/topotests/isis-lfa-topo1/rt2/step1/show_ipv6_route.ref
new file mode 100644
index 000000000..036bfe1f4
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt2/step1/show_ipv6_route.ref
@@ -0,0 +1,162 @@
+{
+  "2001:db8:1000::1\/128":[
+    {
+      "prefix":"2001:db8:1000::1\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":20,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt1",
+          "active":true,
+          "backupIndex":[
+            0
+          ]
+        }
+      ],
+      "backupNexthops":[
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt3",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "2001:db8:1000::3\/128":[
+    {
+      "prefix":"2001:db8:1000::3\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":15,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt3",
+          "active":true,
+          "backupIndex":[
+            0
+          ]
+        }
+      ],
+      "backupNexthops":[
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt1",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "2001:db8:1000::4\/128":[
+    {
+      "prefix":"2001:db8:1000::4\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":30,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt1",
+          "active":true
+        },
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt7",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "2001:db8:1000::5\/128":[
+    {
+      "prefix":"2001:db8:1000::5\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":25,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt7",
+          "active":true,
+          "backupIndex":[
+            0
+          ]
+        }
+      ],
+      "backupNexthops":[
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt1",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "2001:db8:1000::6\/128":[
+    {
+      "prefix":"2001:db8:1000::6\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":25,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt7",
+          "active":true,
+          "backupIndex":[
+            0
+          ]
+        }
+      ],
+      "backupNexthops":[
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt1",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "2001:db8:1000::7\/128":[
+    {
+      "prefix":"2001:db8:1000::7\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":15,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt7",
+          "active":true
+        }
+      ]
+    }
+  ]
+}
diff --git a/tests/topotests/isis-lfa-topo1/rt2/step1/show_yang_interface_isis_adjacencies.ref b/tests/topotests/isis-lfa-topo1/rt2/step1/show_yang_interface_isis_adjacencies.ref
new file mode 100644
index 000000000..681c5222a
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt2/step1/show_yang_interface_isis_adjacencies.ref
@@ -0,0 +1,63 @@
+{
+  "frr-interface:lib": {
+    "interface": [
+      {
+        "name": "eth-rt1",
+        "vrf": "default",
+        "state": {
+          "frr-isisd:isis": {
+            "adjacencies": {
+              "adjacency": [
+                {
+                  "neighbor-sys-type": "level-1",
+                  "neighbor-sysid": "0000.0000.0001",
+                  "hold-timer": 9,
+                  "neighbor-priority": 0,
+                  "state": "up"
+                }
+              ]
+            }
+          }
+        }
+      },
+      {
+        "name": "eth-rt3",
+        "vrf": "default",
+        "state": {
+          "frr-isisd:isis": {
+            "adjacencies": {
+              "adjacency": [
+                {
+                  "neighbor-sys-type": "level-1",
+                  "neighbor-sysid": "0000.0000.0003",
+                  "hold-timer": 9,
+                  "neighbor-priority": 0,
+                  "state": "up"
+                }
+              ]
+            }
+          }
+        }
+      },
+      {
+        "name": "eth-rt7",
+        "vrf": "default",
+        "state": {
+          "frr-isisd:isis": {
+            "adjacencies": {
+              "adjacency": [
+                {
+                  "neighbor-sys-type": "level-1",
+                  "neighbor-sysid": "0000.0000.0007",
+                  "hold-timer": 9,
+                  "neighbor-priority": 0,
+                  "state": "up"
+                }
+              ]
+            }
+          }
+        }
+      }
+    ]
+  }
+}
diff --git a/tests/topotests/isis-lfa-topo1/rt2/zebra.conf b/tests/topotests/isis-lfa-topo1/rt2/zebra.conf
new file mode 100644
index 000000000..9feaada79
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt2/zebra.conf
@@ -0,0 +1,16 @@
+log file zebra.log
+!
+hostname rt2
+!
+debug zebra kernel
+debug zebra packet
+debug zebra mpls
+!
+interface lo
+ ip address 2.2.2.2/32
+ ipv6 address 2001:db8:1000::2/128
+!
+ip forwarding
+!
+line vty
+!
diff --git a/tests/topotests/isis-lfa-topo1/rt3/isisd.conf b/tests/topotests/isis-lfa-topo1/rt3/isisd.conf
new file mode 100644
index 000000000..8b0c7bd0d
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt3/isisd.conf
@@ -0,0 +1,38 @@
+password 1
+hostname rt3
+log file isisd.log
+!
+debug isis events
+debug isis route-events
+debug isis spf-events
+debug isis lsp-gen
+!
+interface lo
+ ipv6 router isis 1
+ isis passive
+!
+interface eth-rt1
+ ipv6 router isis 1
+ isis network point-to-point
+ isis hello-multiplier 3
+ isis fast-reroute lfa
+!
+interface eth-rt2
+ ipv6 router isis 1
+ isis metric 5
+ isis network point-to-point
+ isis hello-multiplier 3
+ isis fast-reroute lfa
+!
+interface eth-rt7
+ ipv6 router isis 1
+ isis network point-to-point
+ isis hello-multiplier 3
+ isis fast-reroute lfa
+!
+router isis 1
+ net 49.0000.0000.0000.0003.00
+ is-type level-1
+ lsp-gen-interval 2
+ topology ipv6-unicast
+!
diff --git a/tests/topotests/isis-lfa-topo1/rt3/step1/show_ipv6_route.ref b/tests/topotests/isis-lfa-topo1/rt3/step1/show_ipv6_route.ref
new file mode 100644
index 000000000..a1aab400e
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt3/step1/show_ipv6_route.ref
@@ -0,0 +1,188 @@
+{
+  "2001:db8:1000::1\/128":[
+    {
+      "prefix":"2001:db8:1000::1\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":20,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt1",
+          "active":true,
+          "backupIndex":[
+            0,
+            1
+          ]
+        }
+      ],
+      "backupNexthops":[
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt2",
+          "active":true
+        },
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt7",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "2001:db8:1000::2\/128":[
+    {
+      "prefix":"2001:db8:1000::2\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":15,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt2",
+          "active":true,
+          "backupIndex":[
+            0,
+            1
+          ]
+        }
+      ],
+      "backupNexthops":[
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt1",
+          "active":true
+        },
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt7",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "2001:db8:1000::4\/128":[
+    {
+      "prefix":"2001:db8:1000::4\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":30,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt1",
+          "active":true,
+          "backupIndex":[
+            0,
+            1
+          ]
+        }
+      ],
+      "backupNexthops":[
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt2",
+          "active":true
+        },
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt7",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "2001:db8:1000::5\/128":[
+    {
+      "prefix":"2001:db8:1000::5\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":30,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt2",
+          "active":true
+        },
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt7",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "2001:db8:1000::6\/128":[
+    {
+      "prefix":"2001:db8:1000::6\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":30,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt2",
+          "active":true
+        },
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt1",
+          "active":true
+        },
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt7",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "2001:db8:1000::7\/128":[
+    {
+      "prefix":"2001:db8:1000::7\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":20,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt2",
+          "active":true
+        },
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt7",
+          "active":true
+        }
+      ]
+    }
+  ]
+}
diff --git a/tests/topotests/isis-lfa-topo1/rt3/step1/show_yang_interface_isis_adjacencies.ref b/tests/topotests/isis-lfa-topo1/rt3/step1/show_yang_interface_isis_adjacencies.ref
new file mode 100644
index 000000000..1495e3228
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt3/step1/show_yang_interface_isis_adjacencies.ref
@@ -0,0 +1,63 @@
+{
+  "frr-interface:lib": {
+    "interface": [
+      {
+        "name": "eth-rt1",
+        "vrf": "default",
+        "state": {
+          "frr-isisd:isis": {
+            "adjacencies": {
+              "adjacency": [
+                {
+                  "neighbor-sys-type": "level-1",
+                  "neighbor-sysid": "0000.0000.0001",
+                  "hold-timer": 9,
+                  "neighbor-priority": 0,
+                  "state": "up"
+                }
+              ]
+            }
+          }
+        }
+      },
+      {
+        "name": "eth-rt2",
+        "vrf": "default",
+        "state": {
+          "frr-isisd:isis": {
+            "adjacencies": {
+              "adjacency": [
+                {
+                  "neighbor-sys-type": "level-1",
+                  "neighbor-sysid": "0000.0000.0002",
+                  "hold-timer": 9,
+                  "neighbor-priority": 0,
+                  "state": "up"
+                }
+              ]
+            }
+          }
+        }
+      },
+      {
+        "name": "eth-rt7",
+        "vrf": "default",
+        "state": {
+          "frr-isisd:isis": {
+            "adjacencies": {
+              "adjacency": [
+                {
+                  "neighbor-sys-type": "level-1",
+                  "neighbor-sysid": "0000.0000.0007",
+                  "hold-timer": 9,
+                  "neighbor-priority": 0,
+                  "state": "up"
+                }
+              ]
+            }
+          }
+        }
+      }
+    ]
+  }
+}
diff --git a/tests/topotests/isis-lfa-topo1/rt3/zebra.conf b/tests/topotests/isis-lfa-topo1/rt3/zebra.conf
new file mode 100644
index 000000000..48d732e72
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt3/zebra.conf
@@ -0,0 +1,16 @@
+log file zebra.log
+!
+hostname rt3
+!
+debug zebra kernel
+debug zebra packet
+debug zebra mpls
+!
+interface lo
+ ip address 3.3.3.3/32
+ ipv6 address 2001:db8:1000::3/128
+!
+ip forwarding
+!
+line vty
+!
diff --git a/tests/topotests/isis-lfa-topo1/rt4/isisd.conf b/tests/topotests/isis-lfa-topo1/rt4/isisd.conf
new file mode 100644
index 000000000..86edee6ab
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt4/isisd.conf
@@ -0,0 +1,32 @@
+password 1
+hostname rt4
+log file isisd.log
+!
+debug isis events
+debug isis route-events
+debug isis spf-events
+debug isis lsp-gen
+!
+interface lo
+ ipv6 router isis 1
+ isis passive
+!
+interface eth-rt1
+ ipv6 router isis 1
+ isis network point-to-point
+ isis hello-multiplier 3
+ isis fast-reroute lfa
+!
+interface eth-rt7
+ ipv6 router isis 1
+ isis metric 15
+ isis network point-to-point
+ isis hello-multiplier 3
+ isis fast-reroute lfa
+!
+router isis 1
+ net 49.0000.0000.0000.0004.00
+ is-type level-1
+ lsp-gen-interval 2
+ topology ipv6-unicast
+!
diff --git a/tests/topotests/isis-lfa-topo1/rt4/step1/show_ipv6_route.ref b/tests/topotests/isis-lfa-topo1/rt4/step1/show_ipv6_route.ref
new file mode 100644
index 000000000..6878e2fac
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt4/step1/show_ipv6_route.ref
@@ -0,0 +1,172 @@
+{
+  "2001:db8:1000::1\/128":[
+    {
+      "prefix":"2001:db8:1000::1\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":20,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt1",
+          "active":true,
+          "backupIndex":[
+            0
+          ]
+        }
+      ],
+      "backupNexthops":[
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt7",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "2001:db8:1000::2\/128":[
+    {
+      "prefix":"2001:db8:1000::2\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":30,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt7",
+          "active":true
+        },
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt1",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "2001:db8:1000::3\/128":[
+    {
+      "prefix":"2001:db8:1000::3\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":30,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt1",
+          "active":true,
+          "backupIndex":[
+            0
+          ]
+        }
+      ],
+      "backupNexthops":[
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt7",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "2001:db8:1000::5\/128":[
+    {
+      "prefix":"2001:db8:1000::5\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":35,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt7",
+          "active":true,
+          "backupIndex":[
+            0
+          ]
+        }
+      ],
+      "backupNexthops":[
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt1",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "2001:db8:1000::6\/128":[
+    {
+      "prefix":"2001:db8:1000::6\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":30,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt1",
+          "active":true,
+          "backupIndex":[
+            0
+          ]
+        }
+      ],
+      "backupNexthops":[
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt7",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "2001:db8:1000::7\/128":[
+    {
+      "prefix":"2001:db8:1000::7\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":25,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt7",
+          "active":true,
+          "backupIndex":[
+            0
+          ]
+        }
+      ],
+      "backupNexthops":[
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt1",
+          "active":true
+        }
+      ]
+    }
+  ]
+}
diff --git a/tests/topotests/isis-lfa-topo1/rt4/step1/show_yang_interface_isis_adjacencies.ref b/tests/topotests/isis-lfa-topo1/rt4/step1/show_yang_interface_isis_adjacencies.ref
new file mode 100644
index 000000000..d8cd565b5
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt4/step1/show_yang_interface_isis_adjacencies.ref
@@ -0,0 +1,44 @@
+{
+  "frr-interface:lib": {
+    "interface": [
+      {
+        "name": "eth-rt1",
+        "vrf": "default",
+        "state": {
+          "frr-isisd:isis": {
+            "adjacencies": {
+              "adjacency": [
+                {
+                  "neighbor-sys-type": "level-1",
+                  "neighbor-sysid": "0000.0000.0001",
+                  "hold-timer": 9,
+                  "neighbor-priority": 0,
+                  "state": "up"
+                }
+              ]
+            }
+          }
+        }
+      },
+      {
+        "name": "eth-rt7",
+        "vrf": "default",
+        "state": {
+          "frr-isisd:isis": {
+            "adjacencies": {
+              "adjacency": [
+                {
+                  "neighbor-sys-type": "level-1",
+                  "neighbor-sysid": "0000.0000.0007",
+                  "hold-timer": 9,
+                  "neighbor-priority": 0,
+                  "state": "up"
+                }
+              ]
+            }
+          }
+        }
+      }
+    ]
+  }
+}
diff --git a/tests/topotests/isis-lfa-topo1/rt4/zebra.conf b/tests/topotests/isis-lfa-topo1/rt4/zebra.conf
new file mode 100644
index 000000000..bff10860c
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt4/zebra.conf
@@ -0,0 +1,16 @@
+log file zebra.log
+!
+hostname rt4
+!
+debug zebra kernel
+debug zebra packet
+debug zebra mpls
+!
+interface lo
+ ip address 4.4.4.4/32
+ ipv6 address 2001:db8:1000::4/128
+!
+ip forwarding
+!
+line vty
+!
diff --git a/tests/topotests/isis-lfa-topo1/rt5/isisd.conf b/tests/topotests/isis-lfa-topo1/rt5/isisd.conf
new file mode 100644
index 000000000..7a7cfe557
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt5/isisd.conf
@@ -0,0 +1,32 @@
+password 1
+hostname rt5
+log file isisd.log
+!
+debug isis events
+debug isis route-events
+debug isis spf-events
+debug isis lsp-gen
+!
+interface lo
+ ipv6 router isis 1
+ isis passive
+!
+interface eth-rt1
+ ipv6 router isis 1
+ isis metric 20
+ isis network point-to-point
+ isis hello-multiplier 3
+ isis fast-reroute lfa
+!
+interface eth-rt7
+ ipv6 router isis 1
+ isis network point-to-point
+ isis hello-multiplier 3
+ isis fast-reroute lfa
+!
+router isis 1
+ net 49.0000.0000.0000.0005.00
+ is-type level-1
+ lsp-gen-interval 2
+ topology ipv6-unicast
+!
diff --git a/tests/topotests/isis-lfa-topo1/rt5/step1/show_ipv6_route.ref b/tests/topotests/isis-lfa-topo1/rt5/step1/show_ipv6_route.ref
new file mode 100644
index 000000000..f8181c776
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt5/step1/show_ipv6_route.ref
@@ -0,0 +1,176 @@
+{
+  "2001:db8:1000::1\/128":[
+    {
+      "prefix":"2001:db8:1000::1\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":30,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt1",
+          "active":true,
+          "backupIndex":[
+            0
+          ]
+        }
+      ],
+      "backupNexthops":[
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt7",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "2001:db8:1000::2\/128":[
+    {
+      "prefix":"2001:db8:1000::2\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":25,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt7",
+          "active":true,
+          "backupIndex":[
+            0
+          ]
+        }
+      ],
+      "backupNexthops":[
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt1",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "2001:db8:1000::3\/128":[
+    {
+      "prefix":"2001:db8:1000::3\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":30,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt7",
+          "active":true,
+          "backupIndex":[
+            0
+          ]
+        }
+      ],
+      "backupNexthops":[
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt1",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "2001:db8:1000::4\/128":[
+    {
+      "prefix":"2001:db8:1000::4\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":35,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt7",
+          "active":true,
+          "backupIndex":[
+            0
+          ]
+        }
+      ],
+      "backupNexthops":[
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt1",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "2001:db8:1000::6\/128":[
+    {
+      "prefix":"2001:db8:1000::6\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":30,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt7",
+          "active":true,
+          "backupIndex":[
+            0
+          ]
+        }
+      ],
+      "backupNexthops":[
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt1",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "2001:db8:1000::7\/128":[
+    {
+      "prefix":"2001:db8:1000::7\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":20,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt7",
+          "active":true,
+          "backupIndex":[
+            0
+          ]
+        }
+      ],
+      "backupNexthops":[
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt1",
+          "active":true
+        }
+      ]
+    }
+  ]
+}
diff --git a/tests/topotests/isis-lfa-topo1/rt5/step1/show_yang_interface_isis_adjacencies.ref b/tests/topotests/isis-lfa-topo1/rt5/step1/show_yang_interface_isis_adjacencies.ref
new file mode 100644
index 000000000..d8cd565b5
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt5/step1/show_yang_interface_isis_adjacencies.ref
@@ -0,0 +1,44 @@
+{
+  "frr-interface:lib": {
+    "interface": [
+      {
+        "name": "eth-rt1",
+        "vrf": "default",
+        "state": {
+          "frr-isisd:isis": {
+            "adjacencies": {
+              "adjacency": [
+                {
+                  "neighbor-sys-type": "level-1",
+                  "neighbor-sysid": "0000.0000.0001",
+                  "hold-timer": 9,
+                  "neighbor-priority": 0,
+                  "state": "up"
+                }
+              ]
+            }
+          }
+        }
+      },
+      {
+        "name": "eth-rt7",
+        "vrf": "default",
+        "state": {
+          "frr-isisd:isis": {
+            "adjacencies": {
+              "adjacency": [
+                {
+                  "neighbor-sys-type": "level-1",
+                  "neighbor-sysid": "0000.0000.0007",
+                  "hold-timer": 9,
+                  "neighbor-priority": 0,
+                  "state": "up"
+                }
+              ]
+            }
+          }
+        }
+      }
+    ]
+  }
+}
diff --git a/tests/topotests/isis-lfa-topo1/rt5/zebra.conf b/tests/topotests/isis-lfa-topo1/rt5/zebra.conf
new file mode 100644
index 000000000..ee1e46c96
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt5/zebra.conf
@@ -0,0 +1,16 @@
+log file zebra.log
+!
+hostname rt5
+!
+debug zebra kernel
+debug zebra packet
+debug zebra mpls
+!
+interface lo
+ ip address 5.5.5.5/32
+ ipv6 address 2001:db8:1000::5/128
+!
+ip forwarding
+!
+line vty
+!
diff --git a/tests/topotests/isis-lfa-topo1/rt6/isisd.conf b/tests/topotests/isis-lfa-topo1/rt6/isisd.conf
new file mode 100644
index 000000000..20cb7769a
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt6/isisd.conf
@@ -0,0 +1,31 @@
+password 1
+hostname rt6
+log file isisd.log
+!
+debug isis events
+debug isis route-events
+debug isis spf-events
+debug isis lsp-gen
+!
+interface lo
+ ipv6 router isis 1
+ isis passive
+!
+interface eth-rt1
+ ipv6 router isis 1
+ isis network point-to-point
+ isis hello-multiplier 3
+ isis fast-reroute lfa
+!
+interface eth-rt7
+ ipv6 router isis 1
+ isis network point-to-point
+ isis hello-multiplier 3
+ isis fast-reroute lfa
+!
+router isis 1
+ net 49.0000.0000.0000.0006.00
+ is-type level-1
+ lsp-gen-interval 2
+ topology ipv6-unicast
+!
diff --git a/tests/topotests/isis-lfa-topo1/rt6/step1/show_ipv6_route.ref b/tests/topotests/isis-lfa-topo1/rt6/step1/show_ipv6_route.ref
new file mode 100644
index 000000000..e5f3c77ac
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt6/step1/show_ipv6_route.ref
@@ -0,0 +1,172 @@
+{
+  "2001:db8:1000::1\/128":[
+    {
+      "prefix":"2001:db8:1000::1\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":20,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt1",
+          "active":true,
+          "backupIndex":[
+            0
+          ]
+        }
+      ],
+      "backupNexthops":[
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt7",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "2001:db8:1000::2\/128":[
+    {
+      "prefix":"2001:db8:1000::2\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":25,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt7",
+          "active":true,
+          "backupIndex":[
+            0
+          ]
+        }
+      ],
+      "backupNexthops":[
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt1",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "2001:db8:1000::3\/128":[
+    {
+      "prefix":"2001:db8:1000::3\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":30,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt1",
+          "active":true
+        },
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt7",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "2001:db8:1000::4\/128":[
+    {
+      "prefix":"2001:db8:1000::4\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":30,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt1",
+          "active":true,
+          "backupIndex":[
+            0
+          ]
+        }
+      ],
+      "backupNexthops":[
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt7",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "2001:db8:1000::5\/128":[
+    {
+      "prefix":"2001:db8:1000::5\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":30,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt7",
+          "active":true,
+          "backupIndex":[
+            0
+          ]
+        }
+      ],
+      "backupNexthops":[
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt1",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "2001:db8:1000::7\/128":[
+    {
+      "prefix":"2001:db8:1000::7\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":20,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt7",
+          "active":true,
+          "backupIndex":[
+            0
+          ]
+        }
+      ],
+      "backupNexthops":[
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt1",
+          "active":true
+        }
+      ]
+    }
+  ]
+}
diff --git a/tests/topotests/isis-lfa-topo1/rt6/step1/show_yang_interface_isis_adjacencies.ref b/tests/topotests/isis-lfa-topo1/rt6/step1/show_yang_interface_isis_adjacencies.ref
new file mode 100644
index 000000000..d8cd565b5
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt6/step1/show_yang_interface_isis_adjacencies.ref
@@ -0,0 +1,44 @@
+{
+  "frr-interface:lib": {
+    "interface": [
+      {
+        "name": "eth-rt1",
+        "vrf": "default",
+        "state": {
+          "frr-isisd:isis": {
+            "adjacencies": {
+              "adjacency": [
+                {
+                  "neighbor-sys-type": "level-1",
+                  "neighbor-sysid": "0000.0000.0001",
+                  "hold-timer": 9,
+                  "neighbor-priority": 0,
+                  "state": "up"
+                }
+              ]
+            }
+          }
+        }
+      },
+      {
+        "name": "eth-rt7",
+        "vrf": "default",
+        "state": {
+          "frr-isisd:isis": {
+            "adjacencies": {
+              "adjacency": [
+                {
+                  "neighbor-sys-type": "level-1",
+                  "neighbor-sysid": "0000.0000.0007",
+                  "hold-timer": 9,
+                  "neighbor-priority": 0,
+                  "state": "up"
+                }
+              ]
+            }
+          }
+        }
+      }
+    ]
+  }
+}
diff --git a/tests/topotests/isis-lfa-topo1/rt6/zebra.conf b/tests/topotests/isis-lfa-topo1/rt6/zebra.conf
new file mode 100644
index 000000000..410807889
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt6/zebra.conf
@@ -0,0 +1,16 @@
+log file zebra.log
+!
+hostname rt6
+!
+debug zebra kernel
+debug zebra packet
+debug zebra mpls
+!
+interface lo
+ ip address 6.6.6.6/32
+ ipv6 address 2001:db8:1000::6/128
+!
+ip forwarding
+!
+line vty
+!
diff --git a/tests/topotests/isis-lfa-topo1/rt7/isisd.conf b/tests/topotests/isis-lfa-topo1/rt7/isisd.conf
new file mode 100644
index 000000000..713e6d39f
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt7/isisd.conf
@@ -0,0 +1,51 @@
+password 1
+hostname rt6
+log file isisd.log
+!
+debug isis events
+debug isis route-events
+debug isis spf-events
+debug isis lsp-gen
+!
+interface lo
+ ipv6 router isis 1
+ isis passive
+!
+interface eth-rt2
+ ipv6 router isis 1
+ isis metric 5
+ isis network point-to-point
+ isis hello-multiplier 3
+ isis fast-reroute lfa
+!
+interface eth-rt3
+ ipv6 router isis 1
+ isis network point-to-point
+ isis hello-multiplier 3
+ isis fast-reroute lfa
+!
+interface eth-rt4
+ ipv6 router isis 1
+ isis metric 15
+ isis network point-to-point
+ isis hello-multiplier 3
+ isis fast-reroute lfa
+!
+interface eth-rt5
+ ipv6 router isis 1
+ isis network point-to-point
+ isis hello-multiplier 3
+ isis fast-reroute lfa
+!
+interface eth-rt6
+ ipv6 router isis 1
+ isis network point-to-point
+ isis hello-multiplier 3
+ isis fast-reroute lfa
+!
+router isis 1
+ net 49.0000.0000.0000.0007.00
+ is-type level-1
+ lsp-gen-interval 2
+ topology ipv6-unicast
+!
diff --git a/tests/topotests/isis-lfa-topo1/rt7/step1/show_ipv6_route.ref b/tests/topotests/isis-lfa-topo1/rt7/step1/show_ipv6_route.ref
new file mode 100644
index 000000000..0dff15e3f
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt7/step1/show_ipv6_route.ref
@@ -0,0 +1,186 @@
+{
+  "2001:db8:1000::1\/128":[
+    {
+      "prefix":"2001:db8:1000::1\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":25,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt2",
+          "active":true,
+          "backupIndex":[
+            0,
+            1,
+            2,
+            3
+          ]
+        }
+      ],
+      "backupNexthops":[
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt3",
+          "active":true
+        },
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt4",
+          "active":true
+        },
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt5",
+          "active":true
+        },
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt6",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "2001:db8:1000::2\/128":[
+    {
+      "prefix":"2001:db8:1000::2\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":15,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt2",
+          "active":true,
+          "backupIndex":[
+            0
+          ]
+        }
+      ],
+      "backupNexthops":[
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt3",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "2001:db8:1000::3\/128":[
+    {
+      "prefix":"2001:db8:1000::3\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":20,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt3",
+          "active":true
+        },
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt2",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "2001:db8:1000::4\/128":[
+    {
+      "prefix":"2001:db8:1000::4\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":25,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt4",
+          "active":true,
+          "backupIndex":[
+            0,
+            1
+          ]
+        }
+      ],
+      "backupNexthops":[
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt3",
+          "active":true
+        },
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt6",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "2001:db8:1000::5\/128":[
+    {
+      "prefix":"2001:db8:1000::5\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":20,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt5",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "2001:db8:1000::6\/128":[
+    {
+      "prefix":"2001:db8:1000::6\/128",
+      "protocol":"isis",
+      "selected":true,
+      "destSelected":true,
+      "distance":115,
+      "metric":20,
+      "installed":true,
+      "nexthops":[
+        {
+          "fib":true,
+          "afi":"ipv6",
+          "interfaceName":"eth-rt6",
+          "active":true,
+          "backupIndex":[
+            0
+          ]
+        }
+      ],
+      "backupNexthops":[
+        {
+          "afi":"ipv6",
+          "interfaceName":"eth-rt4",
+          "active":true
+        }
+      ]
+    }
+  ]
+}
diff --git a/tests/topotests/isis-lfa-topo1/rt7/step1/show_yang_interface_isis_adjacencies.ref b/tests/topotests/isis-lfa-topo1/rt7/step1/show_yang_interface_isis_adjacencies.ref
new file mode 100644
index 000000000..d8a7c5a9c
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt7/step1/show_yang_interface_isis_adjacencies.ref
@@ -0,0 +1,101 @@
+{
+  "frr-interface:lib": {
+    "interface": [
+      {
+        "name": "eth-rt2",
+        "vrf": "default",
+        "state": {
+          "frr-isisd:isis": {
+            "adjacencies": {
+              "adjacency": [
+                {
+                  "neighbor-sys-type": "level-1",
+                  "neighbor-sysid": "0000.0000.0002",
+                  "hold-timer": 9,
+                  "neighbor-priority": 0,
+                  "state": "up"
+                }
+              ]
+            }
+          }
+        }
+      },
+      {
+        "name": "eth-rt3",
+        "vrf": "default",
+        "state": {
+          "frr-isisd:isis": {
+            "adjacencies": {
+              "adjacency": [
+                {
+                  "neighbor-sys-type": "level-1",
+                  "neighbor-sysid": "0000.0000.0003",
+                  "hold-timer": 9,
+                  "neighbor-priority": 0,
+                  "state": "up"
+                }
+              ]
+            }
+          }
+        }
+      },
+      {
+        "name": "eth-rt4",
+        "vrf": "default",
+        "state": {
+          "frr-isisd:isis": {
+            "adjacencies": {
+              "adjacency": [
+                {
+                  "neighbor-sys-type": "level-1",
+                  "neighbor-sysid": "0000.0000.0004",
+                  "hold-timer": 9,
+                  "neighbor-priority": 0,
+                  "state": "up"
+                }
+              ]
+            }
+          }
+        }
+      },
+      {
+        "name": "eth-rt5",
+        "vrf": "default",
+        "state": {
+          "frr-isisd:isis": {
+            "adjacencies": {
+              "adjacency": [
+                {
+                  "neighbor-sys-type": "level-1",
+                  "neighbor-sysid": "0000.0000.0005",
+                  "hold-timer": 9,
+                  "neighbor-priority": 0,
+                  "state": "up"
+                }
+              ]
+            }
+          }
+        }
+      },
+      {
+        "name": "eth-rt6",
+        "vrf": "default",
+        "state": {
+          "frr-isisd:isis": {
+            "adjacencies": {
+              "adjacency": [
+                {
+                  "neighbor-sys-type": "level-1",
+                  "neighbor-sysid": "0000.0000.0006",
+                  "hold-timer": 9,
+                  "neighbor-priority": 0,
+                  "state": "up"
+                }
+              ]
+            }
+          }
+        }
+      }
+    ]
+  }
+}
diff --git a/tests/topotests/isis-lfa-topo1/rt7/zebra.conf b/tests/topotests/isis-lfa-topo1/rt7/zebra.conf
new file mode 100644
index 000000000..353c9efa9
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/rt7/zebra.conf
@@ -0,0 +1,16 @@
+log file zebra.log
+!
+hostname rt7
+!
+debug zebra kernel
+debug zebra packet
+debug zebra mpls
+!
+interface lo
+ ip address 7.7.7.7/32
+ ipv6 address 2001:db8:1000::7/128
+!
+ip forwarding
+!
+line vty
+!
diff --git a/tests/topotests/isis-lfa-topo1/test_isis_lfa_topo1.py b/tests/topotests/isis-lfa-topo1/test_isis_lfa_topo1.py
new file mode 100755
index 000000000..67edcae90
--- /dev/null
+++ b/tests/topotests/isis-lfa-topo1/test_isis_lfa_topo1.py
@@ -0,0 +1,545 @@
+#!/usr/bin/env python
+
+#
+# test_isis_tilfa_topo1.py
+# Part of NetDEF Topology Tests
+#
+# Copyright (c) 2020 by
+# Network Device Education Foundation, Inc. ("NetDEF")
+#
+# Permission to use, copy, modify, and/or distribute this software
+# for any purpose with or without fee is hereby granted, provided
+# that the above copyright notice and this permission notice appear
+# in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND NETDEF DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NETDEF BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY
+# DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
+# WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
+# ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+# OF THIS SOFTWARE.
+#
+
+"""
+test_isis_lfa_topo1.py:
+
+                                       +---------+
+                                       |         |
+      +--------------------------------+   RT1   +-------------------------------+
+      |                  +-------------+         +-------------+                 |
+      |                  |             |         |             |                 |
+      |                  |             +----+----+             |                 |
+      |                  |                  |                  |20               |
+      |                  |                  |                  |                 |
+      |                  |                  |                  |                 |
+ +----+----+        +----+----+        +----+----+        +----+----+       +----+----+
+ |         |        |         |        |         |        |         |       |         |
+ |   RT2   |   5    |   RT3   |        |   RT4   |        |   RT5   |       |   RT6   |
+ |         +--------+         |        |         |        |         |       |         |
+ |         |        |         |        |         |        |         |       |         |
+ +----+----+        +----+----+        +----+----+        +----+----+       +----+----+
+      |                  |                  |                  |                 |
+      |                  |                  |15                |                 |
+      |5                 |                  |                  |                 |
+      |                  |             +----+----+             |                 |
+      |                  |             |         |             |                 |
+      |                  +-------------+   RT7   +-------------+                 |
+      +--------------------------------+         +-------------------------------+
+                                       |         |
+                                       +---------+
+"""
+
+import os
+import sys
+import pytest
+import json
+import re
+import tempfile
+from time import sleep
+from functools import partial
+
+# Save the Current Working Directory to find configuration files.
+CWD = os.path.dirname(os.path.realpath(__file__))
+sys.path.append(os.path.join(CWD, '../'))
+
+# pylint: disable=C0413
+# Import topogen and topotest helpers
+from lib import topotest
+from lib.topogen import Topogen, TopoRouter, get_topogen
+from lib.topolog import logger
+
+# Required to instantiate the topology builder class.
+from mininet.topo import Topo
+
+# Global multi-dimensional dictionary containing all expected outputs
+outputs = {}
+
+class TemplateTopo(Topo):
+    "Test topology builder"
+    def build(self, *_args, **_opts):
+        "Build function"
+        tgen = get_topogen(self)
+
+        #
+        # Define FRR Routers
+        #
+        for router in ['rt1', 'rt2', 'rt3', 'rt4', 'rt5', 'rt6', 'rt7']:
+            tgen.add_router(router)
+
+        #
+        # Define connections
+        #
+        switch = tgen.add_switch('s1')
+        switch.add_link(tgen.gears['rt1'], nodeif="eth-rt2")
+        switch.add_link(tgen.gears['rt2'], nodeif="eth-rt1")
+        switch = tgen.add_switch('s2')
+        switch.add_link(tgen.gears['rt2'], nodeif="eth-rt3")
+        switch.add_link(tgen.gears['rt3'], nodeif="eth-rt2")
+        switch = tgen.add_switch('s3')
+        switch.add_link(tgen.gears['rt1'], nodeif="eth-rt3")
+        switch.add_link(tgen.gears['rt3'], nodeif="eth-rt1")
+        switch = tgen.add_switch('s4')
+        switch.add_link(tgen.gears['rt1'], nodeif="eth-rt4")
+        switch.add_link(tgen.gears['rt4'], nodeif="eth-rt1")
+        switch = tgen.add_switch('s5')
+        switch.add_link(tgen.gears['rt1'], nodeif="eth-rt5")
+        switch.add_link(tgen.gears['rt5'], nodeif="eth-rt1")
+        switch = tgen.add_switch('s6')
+        switch.add_link(tgen.gears['rt1'], nodeif="eth-rt6")
+        switch.add_link(tgen.gears['rt6'], nodeif="eth-rt1")
+        switch = tgen.add_switch('s7')
+        switch.add_link(tgen.gears['rt2'], nodeif="eth-rt7")
+        switch.add_link(tgen.gears['rt7'], nodeif="eth-rt2")
+        switch = tgen.add_switch('s8')
+        switch.add_link(tgen.gears['rt3'], nodeif="eth-rt7")
+        switch.add_link(tgen.gears['rt7'], nodeif="eth-rt3")
+        switch = tgen.add_switch('s9')
+        switch.add_link(tgen.gears['rt4'], nodeif="eth-rt7")
+        switch.add_link(tgen.gears['rt7'], nodeif="eth-rt4")
+        switch = tgen.add_switch('s10')
+        switch.add_link(tgen.gears['rt5'], nodeif="eth-rt7")
+        switch.add_link(tgen.gears['rt7'], nodeif="eth-rt5")
+        switch = tgen.add_switch('s11')
+        switch.add_link(tgen.gears['rt6'], nodeif="eth-rt7")
+        switch.add_link(tgen.gears['rt7'], nodeif="eth-rt6")
+
+        #
+        # Populate multi-dimensional dictionary containing all expected outputs
+        #
+        files = ["show_ipv6_route.ref",
+                 "show_yang_interface_isis_adjacencies.ref"]
+        for rname in ['rt1', 'rt2', 'rt3', 'rt4', 'rt5', 'rt6', 'rt7']:
+            outputs[rname] = {}
+            for step in range(1, 13 + 1):
+                outputs[rname][step] = {}
+                for file in files:
+                    if step == 1:
+                        # Get snapshots relative to the expected initial network convergence
+                        filename = '{}/{}/step{}/{}'.format(CWD, rname, step, file)
+                        outputs[rname][step][file] = open(filename).read()
+                    else:
+                        if rname != "rt1":
+                            continue
+                        if file == "show_yang_interface_isis_adjacencies.ref":
+                            continue
+
+                        # Get diff relative to the previous step
+                        filename = '{}/{}/step{}/{}.diff'.format(CWD, rname, step, file)
+
+                        # Create temporary files in order to apply the diff
+                        f_in = tempfile.NamedTemporaryFile()
+                        f_in.write(outputs[rname][step - 1][file])
+                        f_in.flush()
+                        f_out = tempfile.NamedTemporaryFile()
+                        os.system("patch -s -o %s %s %s" %(f_out.name, f_in.name, filename))
+
+                        # Store the updated snapshot and remove the temporary files
+                        outputs[rname][step][file] = open(f_out.name).read()
+                        f_in.close()
+                        f_out.close()
+
+def setup_module(mod):
+    "Sets up the pytest environment"
+    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen.start_topology()
+
+    router_list = tgen.routers()
+
+    # For all registered routers, load the zebra configuration file
+    for rname, router in router_list.iteritems():
+        router.load_config(
+            TopoRouter.RD_ZEBRA,
+            os.path.join(CWD, '{}/zebra.conf'.format(rname))
+        )
+        router.load_config(
+            TopoRouter.RD_ISIS,
+            os.path.join(CWD, '{}/isisd.conf'.format(rname))
+        )
+
+    tgen.start_router()
+
+def teardown_module(mod):
+    "Teardown the pytest environment"
+    tgen = get_topogen()
+
+    # This function tears down the whole topology.
+    tgen.stop_topology()
+
+def router_compare_json_output(rname, command, reference):
+    "Compare router JSON output"
+
+    logger.info('Comparing router "%s" "%s" output', rname, command)
+
+    tgen = get_topogen()
+    expected = json.loads(reference)
+
+    # Run test function until we get an result. Wait at most 60 seconds.
+    test_func = partial(topotest.router_json_cmp,
+        tgen.gears[rname], command, expected)
+    _, diff = topotest.run_and_expect(test_func, None, count=120, wait=0.5)
+    assertmsg = '"{}" JSON output mismatches the expected result'.format(rname)
+    assert diff is None, assertmsg
+
+#
+# Step 1
+#
+# Test initial network convergence
+#
+def test_isis_adjacencies_step1():
+    logger.info("Test (step 1): check IS-IS adjacencies")
+    tgen = get_topogen()
+
+    # Skip if previous fatal error condition is raised
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    for rname in ['rt1', 'rt2', 'rt3', 'rt4', 'rt5', 'rt6', 'rt7']:
+        router_compare_json_output(rname, "show yang operational-data /frr-interface:lib isisd",
+                                   outputs[rname][1]["show_yang_interface_isis_adjacencies.ref"])
+
+def test_rib_ipv6_step1():
+    logger.info("Test (step 1): verify IPv6 RIB")
+    tgen = get_topogen()
+
+    # Skip if previous fatal error condition is raised
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    for rname in ['rt1', 'rt2', 'rt3', 'rt4', 'rt5', 'rt6', 'rt7']:
+        router_compare_json_output(rname, "show ipv6 route isis json",
+                                   outputs[rname][1]["show_ipv6_route.ref"])
+
+#
+# Step 2
+#
+# Action(s):
+# -Disable LFA protection on all interfaces
+#
+# Expected changes:
+# -rt1 should uninstall all backup nexthops from all routes
+#
+def test_rib_ipv6_step2():
+    logger.info("Test (step 2): verify IPv6 RIB")
+    tgen = get_topogen()
+
+    # Skip if previous fatal error condition is raised
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    logger.info('Disabling LFA protection on all rt1 interfaces')
+    tgen.net['rt1'].cmd('vtysh -c "conf t" -c "interface eth-rt2" -c "no isis fast-reroute lfa"')
+    tgen.net['rt1'].cmd('vtysh -c "conf t" -c "interface eth-rt3" -c "no isis fast-reroute lfa"')
+    tgen.net['rt1'].cmd('vtysh -c "conf t" -c "interface eth-rt4" -c "no isis fast-reroute lfa"')
+    tgen.net['rt1'].cmd('vtysh -c "conf t" -c "interface eth-rt5" -c "no isis fast-reroute lfa"')
+    tgen.net['rt1'].cmd('vtysh -c "conf t" -c "interface eth-rt6" -c "no isis fast-reroute lfa"')
+
+    for rname in ['rt1']:
+        router_compare_json_output(rname, "show ipv6 route isis json",
+                                   outputs[rname][2]["show_ipv6_route.ref"])
+
+#
+# Step 3
+#
+# Action(s):
+# -Re-enable LFA protection on all interfaces
+#
+# Expected changes:
+# -Revert changes from the previous step
+#
+def test_rib_ipv6_step3():
+    logger.info("Test (step 3): verify IPv6 RIB")
+    tgen = get_topogen()
+
+    # Skip if previous fatal error condition is raised
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    logger.info('Re-enabling LFA protection on all rt1 interfaces')
+    tgen.net['rt1'].cmd('vtysh -c "conf t" -c "interface eth-rt2" -c "isis fast-reroute lfa"')
+    tgen.net['rt1'].cmd('vtysh -c "conf t" -c "interface eth-rt3" -c "isis fast-reroute lfa"')
+    tgen.net['rt1'].cmd('vtysh -c "conf t" -c "interface eth-rt4" -c "isis fast-reroute lfa"')
+    tgen.net['rt1'].cmd('vtysh -c "conf t" -c "interface eth-rt5" -c "isis fast-reroute lfa"')
+    tgen.net['rt1'].cmd('vtysh -c "conf t" -c "interface eth-rt6" -c "isis fast-reroute lfa"')
+
+    for rname in ['rt1']:
+        router_compare_json_output(rname, "show ipv6 route isis json",
+                                   outputs[rname][3]["show_ipv6_route.ref"])
+
+#
+# Step 4
+#
+# Action(s):
+# -Disable LFA load-sharing
+#
+# Expected changes:
+# -rt1 should use at most one backup nexthop for each route
+#
+def test_rib_ipv6_step4():
+    logger.info("Test (step 4): verify IPv6 RIB")
+    tgen = get_topogen()
+
+    # Skip if previous fatal error condition is raised
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    logger.info('Disabling LFA load-sharing on rt1')
+    tgen.net['rt1'].cmd('vtysh -c "conf t" -c "router isis 1" -c "fast-reroute load-sharing disable"')
+
+    for rname in ['rt1']:
+        router_compare_json_output(rname, "show ipv6 route isis json",
+                                   outputs[rname][4]["show_ipv6_route.ref"])
+
+#
+# Step 5
+#
+# Action(s):
+# -Re-enable LFA load-sharing
+#
+# Expected changes:
+# -Revert changes from the previous step
+#
+def test_rib_ipv6_step5():
+    logger.info("Test (step 5): verify IPv6 RIB")
+    tgen = get_topogen()
+
+    # Skip if previous fatal error condition is raised
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    logger.info('Re-enabling LFA load-sharing on rt1')
+    tgen.net['rt1'].cmd('vtysh -c "conf t" -c "router isis 1" -c "no fast-reroute load-sharing disable"')
+
+    for rname in ['rt1']:
+        router_compare_json_output(rname, "show ipv6 route isis json",
+                                   outputs[rname][5]["show_ipv6_route.ref"])
+
+#
+# Step 6
+#
+# Action(s):
+# -Limit backup computation to critical priority prefixes only
+#
+# Expected changes:
+# -rt1 should uninstall all backup nexthops from all routes
+#
+def test_rib_ipv6_step6():
+    logger.info("Test (step 6): verify IPv6 RIB")
+    tgen = get_topogen()
+
+    # Skip if previous fatal error condition is raised
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    logger.info('Limiting backup computation to critical priority prefixes only')
+    tgen.net['rt1'].cmd('vtysh -c "conf t" -c "router isis 1" -c "fast-reroute priority-limit critical"')
+
+    for rname in ['rt1']:
+        router_compare_json_output(rname, "show ipv6 route isis json",
+                                   outputs[rname][6]["show_ipv6_route.ref"])
+
+#
+# Step 7
+#
+# Action(s):
+# -Configure a prefix priority list to classify rt7's loopback as a
+#  critical-priority prefix
+#
+# Expected changes:
+# -rt1 should install backup nexthops for rt7's loopback route.
+#
+def test_rib_ipv6_step7():
+    logger.info("Test (step 7): verify IPv6 RIB")
+    tgen = get_topogen()
+
+    # Skip if previous fatal error condition is raised
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    logger.info('Configuring a prefix priority list')
+    tgen.net['rt1'].cmd('vtysh -c "conf t" -c "router isis 1" -c "spf prefix-priority critical CRITICAL_DESTINATIONS"')
+    tgen.net['rt1'].cmd('vtysh -c "conf t" -c "ipv6 access-list CRITICAL_DESTINATIONS seq 5 permit 2001:db8:1000::7/128"')
+
+    for rname in ['rt1']:
+        router_compare_json_output(rname, "show ipv6 route isis json",
+                                   outputs[rname][7]["show_ipv6_route.ref"])
+
+#
+# Step 8
+#
+# Action(s):
+# -Revert previous changes related to prefix priorities
+#
+# Expected changes:
+# -Revert changes from the previous two steps
+#
+def test_rib_ipv6_step8():
+    logger.info("Test (step 8): verify IPv6 RIB")
+    tgen = get_topogen()
+
+    # Skip if previous fatal error condition is raised
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    logger.info('Reverting previous changes related to prefix priorities')
+    tgen.net['rt1'].cmd('vtysh -c "conf t" -c "no ipv6 access-list CRITICAL_DESTINATIONS seq 5 permit 2001:db8:1000::7/128"')
+    tgen.net['rt1'].cmd('vtysh -c "conf t" -c "router isis 1" -c "no fast-reroute priority-limit critical"')
+    tgen.net['rt1'].cmd('vtysh -c "conf t" -c "router isis 1" -c "no spf prefix-priority critical CRITICAL_DESTINATIONS"')
+
+    for rname in ['rt1']:
+        router_compare_json_output(rname, "show ipv6 route isis json",
+                                   outputs[rname][8]["show_ipv6_route.ref"])
+
+#
+# Step 9
+#
+# Action(s):
+# -Exclude eth-rt6 from LFA computation for eth-rt2's failure
+#
+# Expected changes:
+# -Uninstall the eth-rt2 protecting backup nexthops that go through eth-rt6
+#
+def test_rib_ipv6_step9():
+    logger.info("Test (step 9): verify IPv6 RIB")
+    tgen = get_topogen()
+
+    # Skip if previous fatal error condition is raised
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    logger.info('Excluding eth-rt6 from LFA computation for eth-rt2\'s failure')
+    tgen.net['rt1'].cmd('vtysh -c "conf t" -c "interface eth-rt2" -c "isis fast-reroute lfa exclude interface eth-rt6"')
+
+    for rname in ['rt1']:
+        router_compare_json_output(rname, "show ipv6 route isis json",
+                                   outputs[rname][9]["show_ipv6_route.ref"])
+
+#
+# Step 10
+#
+# Action(s):
+# -Remove exclusion of eth-rt6 from LFA computation for eth-rt2's failure
+#
+# Expected changes:
+# -Revert changes from the previous step
+#
+def test_rib_ipv6_step10():
+    logger.info("Test (step 10): verify IPv6 RIB")
+    tgen = get_topogen()
+
+    # Skip if previous fatal error condition is raised
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    logger.info('Removing exclusion of eth-rt6 from LFA computation for eth-rt2\'s failure')
+    tgen.net['rt1'].cmd('vtysh -c "conf t" -c "interface eth-rt2" -c "no isis fast-reroute lfa exclude interface eth-rt6"')
+
+    for rname in ['rt1']:
+        router_compare_json_output(rname, "show ipv6 route isis json",
+                                   outputs[rname][10]["show_ipv6_route.ref"])
+
+#
+# Step 11
+#
+# Action(s):
+# -Add LFA tiebreaker: prefer node protecting backup path
+#
+# Expected changes:
+# -rt1 should prefer backup nexthops that provide node protection
+#
+def test_rib_ipv6_step11():
+    logger.info("Test (step 11): verify IPv6 RIB")
+    tgen = get_topogen()
+
+    # Skip if previous fatal error condition is raised
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    logger.info('Adding LFA tiebreaker: prefer node protecting backup path')
+    tgen.net['rt1'].cmd('vtysh -c "conf t" -c "router isis 1" -c "fast-reroute lfa tiebreaker node-protecting index 10"')
+
+    for rname in ['rt1']:
+        router_compare_json_output(rname, "show ipv6 route isis json",
+                                   outputs[rname][11]["show_ipv6_route.ref"])
+
+#
+# Step 12
+#
+# Action(s):
+# -Add LFA tiebreaker: prefer backup path via downstream node
+#
+# Expected changes:
+# -rt1 should prefer backup nexthops that satisfy the downstream condition
+#
+def test_rib_ipv6_step12():
+    logger.info("Test (step 12): verify IPv6 RIB")
+    tgen = get_topogen()
+
+    # Skip if previous fatal error condition is raised
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    logger.info('Adding LFA tiebreaker: prefer backup path via downstream node')
+    tgen.net['rt1'].cmd('vtysh -c "conf t" -c "router isis 1" -c "fast-reroute lfa tiebreaker downstream index 20"')
+
+    for rname in ['rt1']:
+        router_compare_json_output(rname, "show ipv6 route isis json",
+                                   outputs[rname][12]["show_ipv6_route.ref"])
+
+#
+# Step 13
+#
+# Action(s):
+# -Add LFA tiebreaker: prefer backup path with lowest total metric
+#
+# Expected changes:
+# -rt1 should prefer backup nexthops that have the best metric
+#
+def test_rib_ipv6_step13():
+    logger.info("Test (step 13): verify IPv6 RIB")
+    tgen = get_topogen()
+
+    # Skip if previous fatal error condition is raised
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    logger.info('Adding LFA tiebreaker: prefer backup path with lowest total metric')
+    tgen.net['rt1'].cmd('vtysh -c "conf t" -c "router isis 1" -c "fast-reroute lfa tiebreaker lowest-backup-metric index 30"')
+
+    for rname in ['rt1']:
+        router_compare_json_output(rname, "show ipv6 route isis json",
+                                   outputs[rname][13]["show_ipv6_route.ref"])
+
+# Memory leak test template
+def test_memory_leak():
+    "Run the memory leak test and report results."
+    tgen = get_topogen()
+    if not tgen.is_memleak_enabled():
+        pytest.skip('Memory leak test/report is disabled')
+
+    tgen.report_memory_leaks()
+
+if __name__ == '__main__':
+    args = ["-s"] + sys.argv[1:]
+    sys.exit(pytest.main(args))
diff --git a/yang/frr-isisd.yang b/yang/frr-isisd.yang
index c3b39e375..d751a19f0 100644
--- a/yang/frr-isisd.yang
+++ b/yang/frr-isisd.yang
@@ -244,6 +244,10 @@ module frr-isisd {
     }
   }
 
+  typedef access-list-ref {
+    type string;
+  }
+
   grouping redistribute-attributes {
     description
       "Common optional attributes of any redistribute entry.";
@@ -336,6 +340,94 @@ module frr-isisd {
     }
   }
 
+  grouping global-config-lfa {
+    container lfa {
+      description
+        "LFA configuration.";
+
+      leaf load-sharing {
+        type boolean;
+        default "true";
+        description
+          "Load share prefixes across multiple backups.";
+      }
+      leaf priority-limit {
+        type enumeration {
+          enum "critical" {
+            value 0;
+            description
+              "Compute for critical priority prefixes only.";
+          }
+          enum "high" {
+            value 1;
+            description
+              "Compute for critical & high priority prefixes.";
+          }
+          enum "medium" {
+            value 2;
+            description
+              "Compute for critical, high & medium priority prefixes.";
+          }
+        }
+        description
+          "Limit backup computation up to the prefix priority.";
+      }
+      list tiebreaker {
+        key "index";
+        unique "type";
+        description
+          "Configure tiebreaker for multiple backups.";
+        leaf index {
+          type uint8 {
+            range "1..255";
+          }
+          description
+            "Preference order among tiebreakers.";
+        }
+        leaf type {
+          type enumeration {
+            enum "downstream" {
+              value 0;
+              description
+                "Prefer backup path via downstream node.";
+            }
+            enum "lowest-backup-metric" {
+              value 1;
+              description
+                "Prefer backup path with lowest total metric.";
+            }
+            enum "node-protecting" {
+              value 2;
+              description
+                "Prefer node protecting backup path.";
+            }
+          }
+          mandatory true;
+          description
+            "Tiebreaker type.";
+        }
+      }
+    }
+  }
+
+  grouping interface-config-lfa {
+    container lfa {
+      description
+        "LFA configuration.";
+      leaf enable {
+        type boolean;
+        default false;
+        description
+          "Enables LFA computation.";
+      }
+      leaf-list exclude-interface {
+        type frr-interface:interface-ref;
+        description
+          "Exclude an interface from computation.";
+      }
+    }
+  }
+
   grouping interface-config-ti-lfa {
     container ti-lfa {
       description
@@ -664,11 +756,21 @@ module frr-isisd {
       container level-1 {
         description
           "Level-1 IP Fast-reroute configuration.";
+        must "./lfa/enable = 'false' or ./ti-lfa/enable = 'false'" {
+          error-message
+            "Can't enable both classic LFA and TI-LFA in the same interface.";
+        }
+        uses interface-config-lfa;
         uses interface-config-ti-lfa;
       }
       container level-2 {
         description
           "Level-2 IP Fast-reroute configuration.";
+        must "./lfa/enable = 'false' or ./ti-lfa/enable = 'false'" {
+          error-message
+            "Can't enable both classic LFA and TI-LFA in the same interface.";
+        }
+        uses interface-config-lfa;
         uses interface-config-ti-lfa;
       }
     }
@@ -1095,6 +1197,42 @@ module frr-isisd {
               "Minimum time between consecutive level-2 SPFs.";
           }
         }
+
+        container prefix-priorities {
+          description
+            "SPF Prefix Priority configuration";
+
+          container critical {
+            description
+              "Critical prefix priority";
+            leaf access-list-name {
+              type access-list-ref;
+              description
+                "Access List to determine prefixes for
+                 this priority";
+            }
+          }
+          container high {
+            description
+              "High prefix priority";
+            leaf access-list-name {
+              type access-list-ref;
+              description
+                "Access List to determine prefixes for
+                 this priority";
+            }
+          }
+          container medium {
+            description
+              "Medium prefix priority";
+            leaf access-list-name {
+              type access-list-ref;
+              description
+                "Access List to determine prefixes for
+                 this priority";
+            }
+          }
+        }
       }
 
       container area-password {
@@ -1249,6 +1387,21 @@ module frr-isisd {
         }
       }
 
+      container fast-reroute {
+        description
+          "IP Fast-reroute configuration.";
+        container level-1 {
+          description
+            "Level-1 IP Fast-reroute configuration.";
+          uses global-config-lfa;
+        }
+        container level-2 {
+          description
+            "Level-2 IP Fast-reroute configuration.";
+          uses global-config-lfa;
+        }
+      }
+
       leaf log-adjacency-changes {
         type boolean;
         default "false";