isisd: split northbound callbacks into multiple files

Rearrange the isisd northbound callbacks as following:
* isis_nb.h: prototypes of all northbound callbacks.
* isis_nb.c: definition of all northbound callbacks and their
  associated YANG data paths.
* isis_nb_config.c: implementation of YANG configuration nodes.
* isis_nb_state.c: implementation of YANG state nodes.
* isis_nb_notifications.c: implementation of YANG notifications.

This should help to keep to code more organized and easier to
maintain.

No behavior changes intended.

Signed-off-by: Renato Westphal <renato@opensourcerouting.org>

17 files changed, 4503 insertions, 4108 deletions

diff --git a/isisd/isis_adjacency.c b/isisd/isis_adjacency.c
index d2ec6ff56..1d70521e6 100644
--- a/isisd/isis_adjacency.c
+++ b/isisd/isis_adjacency.c
@@ -48,6 +48,7 @@
 #include "isisd/isis_mt.h"
 #include "isisd/isis_tlvs.h"
 #include "isisd/fabricd.h"
+#include "isisd/isis_nb.h"
 
 extern struct isis *isis;
 
@@ -375,6 +376,20 @@ void isis_adj_print(struct isis_adjacency *adj)
 	return;
 }
 
+const char *isis_adj_yang_state(enum isis_adj_state state)
+{
+	switch (state) {
+	case ISIS_ADJ_DOWN:
+		return "down";
+	case ISIS_ADJ_UP:
+		return "up";
+	case ISIS_ADJ_INITIALIZING:
+		return "init";
+	default:
+		return "failed";
+	}
+}
+
 int isis_adj_expire(struct thread *thread)
 {
 	struct isis_adjacency *adj;
diff --git a/isisd/isis_adjacency.h b/isisd/isis_adjacency.h
index 2a4cb6e61..93583fc12 100644
--- a/isisd/isis_adjacency.h
+++ b/isisd/isis_adjacency.h
@@ -121,6 +121,7 @@ DECLARE_HOOK(isis_adj_state_change_hook, (struct isis_adjacency *adj), (adj))
 void isis_adj_state_change(struct isis_adjacency *adj,
 			   enum isis_adj_state state, const char *reason);
 void isis_adj_print(struct isis_adjacency *adj);
+const char *isis_adj_yang_state(enum isis_adj_state state);
 int isis_adj_expire(struct thread *thread);
 void isis_adj_print_vty(struct isis_adjacency *adj, struct vty *vty,
 			char detail);
diff --git a/isisd/isis_circuit.c b/isisd/isis_circuit.c
index 29fb725b0..1d0e6549d 100644
--- a/isisd/isis_circuit.c
+++ b/isisd/isis_circuit.c
@@ -58,6 +58,7 @@
 #include "isisd/isis_mt.h"
 #include "isisd/isis_errors.h"
 #include "isisd/isis_tx_queue.h"
+#include "isisd/isis_nb.h"
 
 DEFINE_QOBJ_TYPE(isis_circuit)
 
diff --git a/isisd/isis_cli.c b/isisd/isis_cli.c
index 37f4dcfab..3144b3c28 100644
--- a/isisd/isis_cli.c
+++ b/isisd/isis_cli.c
@@ -32,7 +32,7 @@
 #include "yang.h"
 #include "lib/linklist.h"
 #include "isisd/isisd.h"
-#include "isisd/isis_cli.h"
+#include "isisd/isis_nb.h"
 #include "isisd/isis_misc.h"
 #include "isisd/isis_circuit.h"
 #include "isisd/isis_csm.h"
diff --git a/isisd/isis_cli.h b/isisd/isis_cli.h
deleted file mode 100644
index 6621dc0fc..000000000
--- a/isisd/isis_cli.h
+++ /dev/null
@@ -1,127 +0,0 @@
-/*
- * Copyright (C) 2018       Volta Networks
- *                          Emanuele Di Pascale
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License as published by the Free
- * Software Foundation; either version 2 of the License, or (at your option)
- * any later version.
- *
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
- * more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; see the file COPYING; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-#ifndef ISISD_ISIS_CLI_H_
-#define ISISD_ISIS_CLI_H_
-
-/* add cli_show declarations here as externs */
-void cli_show_router_isis(struct vty *vty, struct lyd_node *dnode,
-			  bool show_defaults);
-void cli_show_ip_isis_ipv4(struct vty *vty, struct lyd_node *dnode,
-			   bool show_defaults);
-void cli_show_ip_isis_ipv6(struct vty *vty, struct lyd_node *dnode,
-			   bool show_defaults);
-void cli_show_ip_isis_bfd_monitoring(struct vty *vty, struct lyd_node *dnode,
-				     bool show_defaults);
-void cli_show_isis_area_address(struct vty *vty, struct lyd_node *dnode,
-				bool show_defaults);
-void cli_show_isis_is_type(struct vty *vty, struct lyd_node *dnode,
-			   bool show_defaults);
-void cli_show_isis_dynamic_hostname(struct vty *vty, struct lyd_node *dnode,
-				    bool show_defaults);
-void cli_show_isis_attached(struct vty *vty, struct lyd_node *dnode,
-			    bool show_defaults);
-void cli_show_isis_overload(struct vty *vty, struct lyd_node *dnode,
-			    bool show_defaults);
-void cli_show_isis_metric_style(struct vty *vty, struct lyd_node *dnode,
-				bool show_defaults);
-void cli_show_isis_area_pwd(struct vty *vty, struct lyd_node *dnode,
-			    bool show_defaults);
-void cli_show_isis_domain_pwd(struct vty *vty, struct lyd_node *dnode,
-			      bool show_defaults);
-void cli_show_isis_lsp_gen_interval(struct vty *vty, struct lyd_node *dnode,
-				    bool show_defaults);
-void cli_show_isis_lsp_ref_interval(struct vty *vty, struct lyd_node *dnode,
-				    bool show_defaults);
-void cli_show_isis_lsp_max_lifetime(struct vty *vty, struct lyd_node *dnode,
-				    bool show_defaults);
-void cli_show_isis_lsp_mtu(struct vty *vty, struct lyd_node *dnode,
-			   bool show_defaults);
-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_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,
-			   bool show_defaults);
-void cli_show_isis_mpls_te_router_addr(struct vty *vty, struct lyd_node *dnode,
-				       bool show_defaults);
-void cli_show_isis_def_origin_ipv4(struct vty *vty, struct lyd_node *dnode,
-				   bool show_defaults);
-void cli_show_isis_def_origin_ipv6(struct vty *vty, struct lyd_node *dnode,
-				   bool show_defaults);
-void cli_show_isis_redistribute_ipv4(struct vty *vty, struct lyd_node *dnode,
-				     bool show_defaults);
-void cli_show_isis_redistribute_ipv6(struct vty *vty, struct lyd_node *dnode,
-				     bool show_defaults);
-void cli_show_isis_mt_ipv4_multicast(struct vty *vty, struct lyd_node *dnode,
-				     bool show_defaults);
-void cli_show_isis_mt_ipv4_mgmt(struct vty *vty, struct lyd_node *dnode,
-				bool show_defaults);
-void cli_show_isis_mt_ipv6_unicast(struct vty *vty, struct lyd_node *dnode,
-				   bool show_defaults);
-void cli_show_isis_mt_ipv6_multicast(struct vty *vty, struct lyd_node *dnode,
-				     bool show_defaults);
-void cli_show_isis_mt_ipv6_mgmt(struct vty *vty, struct lyd_node *dnode,
-				bool show_defaults);
-void cli_show_isis_mt_ipv6_dstsrc(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,
-			       bool show_defaults);
-void cli_show_ip_isis_metric(struct vty *vty, struct lyd_node *dnode,
-			     bool show_defaults);
-void cli_show_ip_isis_hello_interval(struct vty *vty, struct lyd_node *dnode,
-				     bool show_defaults);
-void cli_show_ip_isis_hello_multi(struct vty *vty, struct lyd_node *dnode,
-				  bool show_defaults);
-void cli_show_ip_isis_threeway_shake(struct vty *vty, struct lyd_node *dnode,
-				     bool show_defaults);
-void cli_show_ip_isis_hello_padding(struct vty *vty, struct lyd_node *dnode,
-				    bool show_defaults);
-void cli_show_ip_isis_csnp_interval(struct vty *vty, struct lyd_node *dnode,
-				    bool show_defaults);
-void cli_show_ip_isis_psnp_interval(struct vty *vty, struct lyd_node *dnode,
-				    bool show_defaults);
-void cli_show_ip_isis_mt_ipv4_unicast(struct vty *vty, struct lyd_node *dnode,
-				      bool show_defaults);
-void cli_show_ip_isis_mt_ipv4_multicast(struct vty *vty, struct lyd_node *dnode,
-					bool show_defaults);
-void cli_show_ip_isis_mt_ipv4_mgmt(struct vty *vty, struct lyd_node *dnode,
-				   bool show_defaults);
-void cli_show_ip_isis_mt_ipv6_unicast(struct vty *vty, struct lyd_node *dnode,
-				      bool show_defaults);
-void cli_show_ip_isis_mt_ipv6_multicast(struct vty *vty, struct lyd_node *dnode,
-					bool show_defaults);
-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_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,
-				   bool show_defaults);
-void cli_show_ip_isis_priority(struct vty *vty, struct lyd_node *dnode,
-			       bool show_defaults);
-void cli_show_isis_log_adjacency(struct vty *vty, struct lyd_node *dnode,
-				 bool show_defaults);
-
-#endif /* ISISD_ISIS_CLI_H_ */
diff --git a/isisd/isis_lsp.c b/isisd/isis_lsp.c
index 061e75883..c0b90e843 100644
--- a/isisd/isis_lsp.c
+++ b/isisd/isis_lsp.c
@@ -57,6 +57,7 @@
 #include "isisd/isis_te.h"
 #include "isisd/fabricd.h"
 #include "isisd/isis_tx_queue.h"
+#include "isisd/isis_nb.h"
 
 static int lsp_refresh(struct thread *thread);
 static int lsp_l1_refresh_pseudo(struct thread *thread);
diff --git a/isisd/isis_main.c b/isisd/isis_main.c
index 718924daf..2ef006518 100644
--- a/isisd/isis_main.c
+++ b/isisd/isis_main.c
@@ -57,6 +57,7 @@
 #include "isisd/isis_lsp.h"
 #include "isisd/isis_mt.h"
 #include "isisd/fabricd.h"
+#include "isisd/isis_nb.h"
 
 /* Default configuration file name */
 #define ISISD_DEFAULT_CONFIG "isisd.conf"
diff --git a/isisd/isis_nb.c b/isisd/isis_nb.c
new file mode 100644
index 000000000..d84e53324
--- /dev/null
+++ b/isisd/isis_nb.c
@@ -0,0 +1,815 @@
+/*
+ * Copyright (C) 2018        Volta Networks
+ *                           Emanuele Di Pascale
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; see the file COPYING; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <zebra.h>
+
+#include "northbound.h"
+#include "libfrr.h"
+
+#include "isisd/isis_nb.h"
+
+/* clang-format off */
+const struct frr_yang_module_info frr_isisd_info = {
+	.name = "frr-isisd",
+	.nodes = {
+		{
+			.xpath = "/frr-isisd:isis/instance",
+			.cbs = {
+				.cli_show = cli_show_router_isis,
+				.create = isis_instance_create,
+				.destroy = isis_instance_destroy,
+			},
+			.priority = NB_DFLT_PRIORITY - 1,
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/is-type",
+			.cbs = {
+				.cli_show = cli_show_isis_is_type,
+				.modify = isis_instance_is_type_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/area-address",
+			.cbs = {
+				.cli_show = cli_show_isis_area_address,
+				.create = isis_instance_area_address_create,
+				.destroy = isis_instance_area_address_destroy,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/dynamic-hostname",
+			.cbs = {
+				.cli_show = cli_show_isis_dynamic_hostname,
+				.modify = isis_instance_dynamic_hostname_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/attached",
+			.cbs = {
+				.cli_show = cli_show_isis_attached,
+				.modify = isis_instance_attached_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/overload",
+			.cbs = {
+				.cli_show = cli_show_isis_overload,
+				.modify = isis_instance_overload_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/metric-style",
+			.cbs = {
+				.cli_show = cli_show_isis_metric_style,
+				.modify = isis_instance_metric_style_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/purge-originator",
+			.cbs = {
+				.cli_show = cli_show_isis_purge_origin,
+				.modify = isis_instance_purge_originator_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/lsp/mtu",
+			.cbs = {
+				.cli_show = cli_show_isis_lsp_mtu,
+				.modify = isis_instance_lsp_mtu_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/lsp/refresh-interval",
+			.cbs = {
+				.cli_show = cli_show_isis_lsp_ref_interval,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/lsp/refresh-interval/level-1",
+			.cbs = {
+				.modify = isis_instance_lsp_refresh_interval_level_1_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/lsp/refresh-interval/level-2",
+			.cbs = {
+				.modify = isis_instance_lsp_refresh_interval_level_2_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/lsp/maximum-lifetime",
+			.cbs = {
+				.cli_show = cli_show_isis_lsp_max_lifetime,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/lsp/maximum-lifetime/level-1",
+			.cbs = {
+				.modify = isis_instance_lsp_maximum_lifetime_level_1_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/lsp/maximum-lifetime/level-2",
+			.cbs = {
+				.modify = isis_instance_lsp_maximum_lifetime_level_2_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/lsp/generation-interval",
+			.cbs = {
+				.cli_show = cli_show_isis_lsp_gen_interval,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/lsp/generation-interval/level-1",
+			.cbs = {
+				.modify = isis_instance_lsp_generation_interval_level_1_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/lsp/generation-interval/level-2",
+			.cbs = {
+				.modify = isis_instance_lsp_generation_interval_level_2_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/spf/ietf-backoff-delay",
+			.cbs = {
+				.apply_finish = ietf_backoff_delay_apply_finish,
+				.cli_show = cli_show_isis_spf_ietf_backoff,
+				.create = isis_instance_spf_ietf_backoff_delay_create,
+				.destroy = isis_instance_spf_ietf_backoff_delay_destroy,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/spf/ietf-backoff-delay/init-delay",
+			.cbs = {
+				.modify = isis_instance_spf_ietf_backoff_delay_init_delay_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/spf/ietf-backoff-delay/short-delay",
+			.cbs = {
+				.modify = isis_instance_spf_ietf_backoff_delay_short_delay_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/spf/ietf-backoff-delay/long-delay",
+			.cbs = {
+				.modify = isis_instance_spf_ietf_backoff_delay_long_delay_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/spf/ietf-backoff-delay/hold-down",
+			.cbs = {
+				.modify = isis_instance_spf_ietf_backoff_delay_hold_down_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/spf/ietf-backoff-delay/time-to-learn",
+			.cbs = {
+				.modify = isis_instance_spf_ietf_backoff_delay_time_to_learn_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/spf/minimum-interval",
+			.cbs = {
+				.cli_show = cli_show_isis_spf_min_interval,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/spf/minimum-interval/level-1",
+			.cbs = {
+				.modify = isis_instance_spf_minimum_interval_level_1_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/spf/minimum-interval/level-2",
+			.cbs = {
+				.modify = isis_instance_spf_minimum_interval_level_2_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/area-password",
+			.cbs = {
+				.apply_finish = area_password_apply_finish,
+				.cli_show = cli_show_isis_area_pwd,
+				.create = isis_instance_area_password_create,
+				.destroy = isis_instance_area_password_destroy,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/area-password/password",
+			.cbs = {
+				.modify = isis_instance_area_password_password_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/area-password/password-type",
+			.cbs = {
+				.modify = isis_instance_area_password_password_type_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/area-password/authenticate-snp",
+			.cbs = {
+				.modify = isis_instance_area_password_authenticate_snp_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/domain-password",
+			.cbs = {
+				.apply_finish = domain_password_apply_finish,
+				.cli_show = cli_show_isis_domain_pwd,
+				.create = isis_instance_domain_password_create,
+				.destroy = isis_instance_domain_password_destroy,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/domain-password/password",
+			.cbs = {
+				.modify = isis_instance_domain_password_password_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/domain-password/password-type",
+			.cbs = {
+				.modify = isis_instance_domain_password_password_type_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/domain-password/authenticate-snp",
+			.cbs = {
+				.modify = isis_instance_domain_password_authenticate_snp_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/default-information-originate/ipv4",
+			.cbs = {
+				.apply_finish = default_info_origin_ipv4_apply_finish,
+				.cli_show = cli_show_isis_def_origin_ipv4,
+				.create = isis_instance_default_information_originate_ipv4_create,
+				.destroy = isis_instance_default_information_originate_ipv4_destroy,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/default-information-originate/ipv4/always",
+			.cbs = {
+				.modify = isis_instance_default_information_originate_ipv4_always_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/default-information-originate/ipv4/route-map",
+			.cbs = {
+				.destroy = isis_instance_default_information_originate_ipv4_route_map_destroy,
+				.modify = isis_instance_default_information_originate_ipv4_route_map_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/default-information-originate/ipv4/metric",
+			.cbs = {
+				.modify = isis_instance_default_information_originate_ipv4_metric_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/default-information-originate/ipv6",
+			.cbs = {
+				.apply_finish = default_info_origin_ipv6_apply_finish,
+				.cli_show = cli_show_isis_def_origin_ipv6,
+				.create = isis_instance_default_information_originate_ipv6_create,
+				.destroy = isis_instance_default_information_originate_ipv6_destroy,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/default-information-originate/ipv6/always",
+			.cbs = {
+				.modify = isis_instance_default_information_originate_ipv6_always_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/default-information-originate/ipv6/route-map",
+			.cbs = {
+				.destroy = isis_instance_default_information_originate_ipv6_route_map_destroy,
+				.modify = isis_instance_default_information_originate_ipv6_route_map_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/default-information-originate/ipv6/metric",
+			.cbs = {
+				.modify = isis_instance_default_information_originate_ipv6_metric_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/redistribute/ipv4",
+			.cbs = {
+				.apply_finish = redistribute_ipv4_apply_finish,
+				.cli_show = cli_show_isis_redistribute_ipv4,
+				.create = isis_instance_redistribute_ipv4_create,
+				.destroy = isis_instance_redistribute_ipv4_destroy,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/redistribute/ipv4/route-map",
+			.cbs = {
+				.destroy = isis_instance_redistribute_ipv4_route_map_destroy,
+				.modify = isis_instance_redistribute_ipv4_route_map_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/redistribute/ipv4/metric",
+			.cbs = {
+				.modify = isis_instance_redistribute_ipv4_metric_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/redistribute/ipv6",
+			.cbs = {
+				.apply_finish = redistribute_ipv6_apply_finish,
+				.cli_show = cli_show_isis_redistribute_ipv6,
+				.create = isis_instance_redistribute_ipv6_create,
+				.destroy = isis_instance_redistribute_ipv6_destroy,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/redistribute/ipv6/route-map",
+			.cbs = {
+				.destroy = isis_instance_redistribute_ipv6_route_map_destroy,
+				.modify = isis_instance_redistribute_ipv6_route_map_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/redistribute/ipv6/metric",
+			.cbs = {
+				.modify = isis_instance_redistribute_ipv6_metric_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/multi-topology/ipv4-multicast",
+			.cbs = {
+				.cli_show = cli_show_isis_mt_ipv4_multicast,
+				.create = isis_instance_multi_topology_ipv4_multicast_create,
+				.destroy = isis_instance_multi_topology_ipv4_multicast_destroy,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/multi-topology/ipv4-multicast/overload",
+			.cbs = {
+				.modify = isis_instance_multi_topology_ipv4_multicast_overload_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/multi-topology/ipv4-management",
+			.cbs = {
+				.cli_show = cli_show_isis_mt_ipv4_mgmt,
+				.create = isis_instance_multi_topology_ipv4_management_create,
+				.destroy = isis_instance_multi_topology_ipv4_management_destroy,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/multi-topology/ipv4-management/overload",
+			.cbs = {
+				.modify = isis_instance_multi_topology_ipv4_management_overload_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/multi-topology/ipv6-unicast",
+			.cbs = {
+				.cli_show = cli_show_isis_mt_ipv6_unicast,
+				.create = isis_instance_multi_topology_ipv6_unicast_create,
+				.destroy = isis_instance_multi_topology_ipv6_unicast_destroy,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/multi-topology/ipv6-unicast/overload",
+			.cbs = {
+				.modify = isis_instance_multi_topology_ipv6_unicast_overload_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/multi-topology/ipv6-multicast",
+			.cbs = {
+				.cli_show = cli_show_isis_mt_ipv6_multicast,
+				.create = isis_instance_multi_topology_ipv6_multicast_create,
+				.destroy = isis_instance_multi_topology_ipv6_multicast_destroy,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/multi-topology/ipv6-multicast/overload",
+			.cbs = {
+				.modify = isis_instance_multi_topology_ipv6_multicast_overload_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/multi-topology/ipv6-management",
+			.cbs = {
+				.cli_show = cli_show_isis_mt_ipv6_mgmt,
+				.create = isis_instance_multi_topology_ipv6_management_create,
+				.destroy = isis_instance_multi_topology_ipv6_management_destroy,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/multi-topology/ipv6-management/overload",
+			.cbs = {
+				.modify = isis_instance_multi_topology_ipv6_management_overload_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/multi-topology/ipv6-dstsrc",
+			.cbs = {
+				.cli_show = cli_show_isis_mt_ipv6_dstsrc,
+				.create = isis_instance_multi_topology_ipv6_dstsrc_create,
+				.destroy = isis_instance_multi_topology_ipv6_dstsrc_destroy,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/multi-topology/ipv6-dstsrc/overload",
+			.cbs = {
+				.modify = isis_instance_multi_topology_ipv6_dstsrc_overload_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/log-adjacency-changes",
+			.cbs = {
+				.cli_show = cli_show_isis_log_adjacency,
+				.modify = isis_instance_log_adjacency_changes_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/mpls-te",
+			.cbs = {
+				.cli_show = cli_show_isis_mpls_te,
+				.create = isis_instance_mpls_te_create,
+				.destroy = isis_instance_mpls_te_destroy,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/mpls-te/router-address",
+			.cbs = {
+				.cli_show = cli_show_isis_mpls_te_router_addr,
+				.destroy = isis_instance_mpls_te_router_address_destroy,
+				.modify = isis_instance_mpls_te_router_address_modify,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis",
+			.cbs = {
+				.create = lib_interface_isis_create,
+				.destroy = lib_interface_isis_destroy,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/area-tag",
+			.cbs = {
+				.modify = lib_interface_isis_area_tag_modify,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/circuit-type",
+			.cbs = {
+				.cli_show = cli_show_ip_isis_circ_type,
+				.modify = lib_interface_isis_circuit_type_modify,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/ipv4-routing",
+			.cbs = {
+				.cli_show = cli_show_ip_isis_ipv4,
+				.modify = lib_interface_isis_ipv4_routing_modify,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/ipv6-routing",
+			.cbs = {
+				.cli_show = cli_show_ip_isis_ipv6,
+				.modify = lib_interface_isis_ipv6_routing_modify,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/bfd-monitoring",
+			.cbs = {
+				.modify = lib_interface_isis_bfd_monitoring_modify,
+				.cli_show = cli_show_ip_isis_bfd_monitoring,
+			}
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/csnp-interval",
+			.cbs = {
+				.cli_show = cli_show_ip_isis_csnp_interval,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/csnp-interval/level-1",
+			.cbs = {
+				.modify = lib_interface_isis_csnp_interval_level_1_modify,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/csnp-interval/level-2",
+			.cbs = {
+				.modify = lib_interface_isis_csnp_interval_level_2_modify,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/psnp-interval",
+			.cbs = {
+				.cli_show = cli_show_ip_isis_psnp_interval,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/psnp-interval/level-1",
+			.cbs = {
+				.modify = lib_interface_isis_psnp_interval_level_1_modify,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/psnp-interval/level-2",
+			.cbs = {
+				.modify = lib_interface_isis_psnp_interval_level_2_modify,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/hello/padding",
+			.cbs = {
+				.cli_show = cli_show_ip_isis_hello_padding,
+				.modify = lib_interface_isis_hello_padding_modify,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/hello/interval",
+			.cbs = {
+				.cli_show = cli_show_ip_isis_hello_interval,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/hello/interval/level-1",
+			.cbs = {
+				.modify = lib_interface_isis_hello_interval_level_1_modify,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/hello/interval/level-2",
+			.cbs = {
+				.modify = lib_interface_isis_hello_interval_level_2_modify,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/hello/multiplier",
+			.cbs = {
+				.cli_show = cli_show_ip_isis_hello_multi,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/hello/multiplier/level-1",
+			.cbs = {
+				.modify = lib_interface_isis_hello_multiplier_level_1_modify,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/hello/multiplier/level-2",
+			.cbs = {
+				.modify = lib_interface_isis_hello_multiplier_level_2_modify,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/metric",
+			.cbs = {
+				.cli_show = cli_show_ip_isis_metric,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/metric/level-1",
+			.cbs = {
+				.modify = lib_interface_isis_metric_level_1_modify,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/metric/level-2",
+			.cbs = {
+				.modify = lib_interface_isis_metric_level_2_modify,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/priority",
+			.cbs = {
+				.cli_show = cli_show_ip_isis_priority,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/priority/level-1",
+			.cbs = {
+				.modify = lib_interface_isis_priority_level_1_modify,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/priority/level-2",
+			.cbs = {
+				.modify = lib_interface_isis_priority_level_2_modify,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/network-type",
+			.cbs = {
+				.cli_show = cli_show_ip_isis_network_type,
+				.modify = lib_interface_isis_network_type_modify,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/passive",
+			.cbs = {
+				.cli_show = cli_show_ip_isis_passive,
+				.modify = lib_interface_isis_passive_modify,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/password",
+			.cbs = {
+				.cli_show = cli_show_ip_isis_password,
+				.create = lib_interface_isis_password_create,
+				.destroy = lib_interface_isis_password_destroy,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/password/password",
+			.cbs = {
+				.modify = lib_interface_isis_password_password_modify,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/password/password-type",
+			.cbs = {
+				.modify = lib_interface_isis_password_password_type_modify,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/disable-three-way-handshake",
+			.cbs = {
+				.cli_show = cli_show_ip_isis_threeway_shake,
+				.modify = lib_interface_isis_disable_three_way_handshake_modify,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/multi-topology/ipv4-unicast",
+			.cbs = {
+				.cli_show = cli_show_ip_isis_mt_ipv4_unicast,
+				.modify = lib_interface_isis_multi_topology_ipv4_unicast_modify,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/multi-topology/ipv4-multicast",
+			.cbs = {
+				.cli_show = cli_show_ip_isis_mt_ipv4_multicast,
+				.modify = lib_interface_isis_multi_topology_ipv4_multicast_modify,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/multi-topology/ipv4-management",
+			.cbs = {
+				.cli_show = cli_show_ip_isis_mt_ipv4_mgmt,
+				.modify = lib_interface_isis_multi_topology_ipv4_management_modify,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/multi-topology/ipv6-unicast",
+			.cbs = {
+				.cli_show = cli_show_ip_isis_mt_ipv6_unicast,
+				.modify = lib_interface_isis_multi_topology_ipv6_unicast_modify,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/multi-topology/ipv6-multicast",
+			.cbs = {
+				.cli_show = cli_show_ip_isis_mt_ipv6_multicast,
+				.modify = lib_interface_isis_multi_topology_ipv6_multicast_modify,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/multi-topology/ipv6-management",
+			.cbs = {
+				.cli_show = cli_show_ip_isis_mt_ipv6_mgmt,
+				.modify = lib_interface_isis_multi_topology_ipv6_management_modify,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/multi-topology/ipv6-dstsrc",
+			.cbs = {
+				.cli_show = cli_show_ip_isis_mt_ipv6_dstsrc,
+				.modify = lib_interface_isis_multi_topology_ipv6_dstsrc_modify,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/adjacencies/adjacency",
+			.cbs = {
+				.get_next = lib_interface_isis_adjacencies_adjacency_get_next,
+			}
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/adjacencies/adjacency/neighbor-sys-type",
+			.cbs = {
+				.get_elem = lib_interface_isis_adjacencies_adjacency_neighbor_sys_type_get_elem,
+			}
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/adjacencies/adjacency/neighbor-sysid",
+			.cbs = {
+				.get_elem = lib_interface_isis_adjacencies_adjacency_neighbor_sysid_get_elem,
+			}
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/adjacencies/adjacency/neighbor-extended-circuit-id",
+			.cbs = {
+				.get_elem = lib_interface_isis_adjacencies_adjacency_neighbor_extended_circuit_id_get_elem,
+			}
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/adjacencies/adjacency/neighbor-snpa",
+			.cbs = {
+				.get_elem = lib_interface_isis_adjacencies_adjacency_neighbor_snpa_get_elem,
+			}
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/adjacencies/adjacency/hold-timer",
+			.cbs = {
+				.get_elem = lib_interface_isis_adjacencies_adjacency_hold_timer_get_elem,
+			}
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/adjacencies/adjacency/neighbor-priority",
+			.cbs = {
+				.get_elem = lib_interface_isis_adjacencies_adjacency_neighbor_priority_get_elem,
+			}
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/adjacencies/adjacency/state",
+			.cbs = {
+				.get_elem = lib_interface_isis_adjacencies_adjacency_state_get_elem,
+			}
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/event-counters/adjacency-changes",
+			.cbs = {
+				.get_elem = lib_interface_isis_event_counters_adjacency_changes_get_elem,
+			}
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/event-counters/adjacency-number",
+			.cbs = {
+				.get_elem = lib_interface_isis_event_counters_adjacency_number_get_elem,
+			}
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/event-counters/init-fails",
+			.cbs = {
+				.get_elem = lib_interface_isis_event_counters_init_fails_get_elem,
+			}
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/event-counters/adjacency-rejects",
+			.cbs = {
+				.get_elem = lib_interface_isis_event_counters_adjacency_rejects_get_elem,
+			}
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/event-counters/id-len-mismatch",
+			.cbs = {
+				.get_elem = lib_interface_isis_event_counters_id_len_mismatch_get_elem,
+			}
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/event-counters/max-area-addresses-mismatch",
+			.cbs = {
+				.get_elem = lib_interface_isis_event_counters_max_area_addresses_mismatch_get_elem,
+			}
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/event-counters/authentication-type-fails",
+			.cbs = {
+				.get_elem = lib_interface_isis_event_counters_authentication_type_fails_get_elem,
+			}
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/event-counters/authentication-fails",
+			.cbs = {
+				.get_elem = lib_interface_isis_event_counters_authentication_fails_get_elem,
+			}
+		},
+		{
+			.xpath = NULL,
+		},
+	}
+};
diff --git a/isisd/isis_nb.h b/isisd/isis_nb.h
new file mode 100644
index 000000000..29a2ded0d
--- /dev/null
+++ b/isisd/isis_nb.h
@@ -0,0 +1,548 @@
+/*
+ * Copyright (C) 2018        Volta Networks
+ *                           Emanuele Di Pascale
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; see the file COPYING; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef ISISD_ISIS_NB_H_
+#define ISISD_ISIS_NB_H_
+
+extern const struct frr_yang_module_info frr_isisd_info;
+
+/* Forward declaration(s). */
+struct isis_area;
+struct isis_circuit;
+struct isis_adjacency;
+
+/* Mandatory callbacks. */
+int isis_instance_create(enum nb_event event, const struct lyd_node *dnode,
+			 union nb_resource *resource);
+int isis_instance_destroy(enum nb_event event, const struct lyd_node *dnode);
+int isis_instance_is_type_modify(enum nb_event event,
+				 const struct lyd_node *dnode,
+				 union nb_resource *resource);
+int isis_instance_area_address_create(enum nb_event event,
+				      const struct lyd_node *dnode,
+				      union nb_resource *resource);
+int isis_instance_area_address_destroy(enum nb_event event,
+				       const struct lyd_node *dnode);
+int isis_instance_dynamic_hostname_modify(enum nb_event event,
+					  const struct lyd_node *dnode,
+					  union nb_resource *resource);
+int isis_instance_attached_modify(enum nb_event event,
+				  const struct lyd_node *dnode,
+				  union nb_resource *resource);
+int isis_instance_overload_modify(enum nb_event event,
+				  const struct lyd_node *dnode,
+				  union nb_resource *resource);
+int isis_instance_metric_style_modify(enum nb_event event,
+				      const struct lyd_node *dnode,
+				      union nb_resource *resource);
+int isis_instance_purge_originator_modify(enum nb_event event,
+					  const struct lyd_node *dnode,
+					  union nb_resource *resource);
+int isis_instance_lsp_mtu_modify(enum nb_event event,
+				 const struct lyd_node *dnode,
+				 union nb_resource *resource);
+int isis_instance_lsp_refresh_interval_level_1_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_lsp_refresh_interval_level_2_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_lsp_maximum_lifetime_level_1_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_lsp_maximum_lifetime_level_2_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_lsp_generation_interval_level_1_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_lsp_generation_interval_level_2_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_spf_ietf_backoff_delay_create(enum nb_event event,
+						const struct lyd_node *dnode,
+						union nb_resource *resource);
+int isis_instance_spf_ietf_backoff_delay_destroy(enum nb_event event,
+						 const struct lyd_node *dnode);
+int isis_instance_spf_ietf_backoff_delay_init_delay_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_spf_ietf_backoff_delay_short_delay_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_spf_ietf_backoff_delay_long_delay_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_spf_ietf_backoff_delay_hold_down_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_spf_ietf_backoff_delay_time_to_learn_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_spf_minimum_interval_level_1_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_spf_minimum_interval_level_2_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_area_password_create(enum nb_event event,
+				       const struct lyd_node *dnode,
+				       union nb_resource *resource);
+int isis_instance_area_password_destroy(enum nb_event event,
+					const struct lyd_node *dnode);
+int isis_instance_area_password_password_modify(enum nb_event event,
+						const struct lyd_node *dnode,
+						union nb_resource *resource);
+int isis_instance_area_password_password_type_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_area_password_authenticate_snp_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_domain_password_create(enum nb_event event,
+					 const struct lyd_node *dnode,
+					 union nb_resource *resource);
+int isis_instance_domain_password_destroy(enum nb_event event,
+					  const struct lyd_node *dnode);
+int isis_instance_domain_password_password_modify(enum nb_event event,
+						  const struct lyd_node *dnode,
+						  union nb_resource *resource);
+int isis_instance_domain_password_password_type_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_domain_password_authenticate_snp_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_default_information_originate_ipv4_create(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_default_information_originate_ipv4_destroy(
+	enum nb_event event, const struct lyd_node *dnode);
+int isis_instance_default_information_originate_ipv4_always_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_default_information_originate_ipv4_route_map_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_default_information_originate_ipv4_route_map_destroy(
+	enum nb_event event, const struct lyd_node *dnode);
+int isis_instance_default_information_originate_ipv4_metric_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_default_information_originate_ipv6_create(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_default_information_originate_ipv6_destroy(
+	enum nb_event event, const struct lyd_node *dnode);
+int isis_instance_default_information_originate_ipv6_always_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_default_information_originate_ipv6_route_map_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_default_information_originate_ipv6_route_map_destroy(
+	enum nb_event event, const struct lyd_node *dnode);
+int isis_instance_default_information_originate_ipv6_metric_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_redistribute_ipv4_create(enum nb_event event,
+					   const struct lyd_node *dnode,
+					   union nb_resource *resource);
+int isis_instance_redistribute_ipv4_destroy(enum nb_event event,
+					    const struct lyd_node *dnode);
+int isis_instance_redistribute_ipv4_route_map_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_redistribute_ipv4_route_map_destroy(
+	enum nb_event event, const struct lyd_node *dnode);
+int isis_instance_redistribute_ipv4_metric_modify(enum nb_event event,
+						  const struct lyd_node *dnode,
+						  union nb_resource *resource);
+int isis_instance_redistribute_ipv6_create(enum nb_event event,
+					   const struct lyd_node *dnode,
+					   union nb_resource *resource);
+int isis_instance_redistribute_ipv6_destroy(enum nb_event event,
+					    const struct lyd_node *dnode);
+int isis_instance_redistribute_ipv6_route_map_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_redistribute_ipv6_route_map_destroy(
+	enum nb_event event, const struct lyd_node *dnode);
+int isis_instance_redistribute_ipv6_metric_modify(enum nb_event event,
+						  const struct lyd_node *dnode,
+						  union nb_resource *resource);
+int isis_instance_multi_topology_ipv4_multicast_create(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_multi_topology_ipv4_multicast_destroy(
+	enum nb_event event, const struct lyd_node *dnode);
+int isis_instance_multi_topology_ipv4_multicast_overload_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_multi_topology_ipv4_management_create(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_multi_topology_ipv4_management_destroy(
+	enum nb_event event, const struct lyd_node *dnode);
+int isis_instance_multi_topology_ipv4_management_overload_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_multi_topology_ipv6_unicast_create(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_multi_topology_ipv6_unicast_destroy(
+	enum nb_event event, const struct lyd_node *dnode);
+int isis_instance_multi_topology_ipv6_unicast_overload_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_multi_topology_ipv6_multicast_create(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_multi_topology_ipv6_multicast_destroy(
+	enum nb_event event, const struct lyd_node *dnode);
+int isis_instance_multi_topology_ipv6_multicast_overload_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_multi_topology_ipv6_management_create(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_multi_topology_ipv6_management_destroy(
+	enum nb_event event, const struct lyd_node *dnode);
+int isis_instance_multi_topology_ipv6_management_overload_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_multi_topology_ipv6_dstsrc_create(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_multi_topology_ipv6_dstsrc_destroy(
+	enum nb_event event, const struct lyd_node *dnode);
+int isis_instance_multi_topology_ipv6_dstsrc_overload_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int isis_instance_log_adjacency_changes_modify(enum nb_event event,
+					       const struct lyd_node *dnode,
+					       union nb_resource *resource);
+int isis_instance_mpls_te_create(enum nb_event event,
+				 const struct lyd_node *dnode,
+				 union nb_resource *resource);
+int isis_instance_mpls_te_destroy(enum nb_event event,
+				  const struct lyd_node *dnode);
+int isis_instance_mpls_te_router_address_modify(enum nb_event event,
+						const struct lyd_node *dnode,
+						union nb_resource *resource);
+int isis_instance_mpls_te_router_address_destroy(enum nb_event event,
+						 const struct lyd_node *dnode);
+int lib_interface_isis_create(enum nb_event event, const struct lyd_node *dnode,
+			      union nb_resource *resource);
+int lib_interface_isis_destroy(enum nb_event event,
+			       const struct lyd_node *dnode);
+int lib_interface_isis_area_tag_modify(enum nb_event event,
+				       const struct lyd_node *dnode,
+				       union nb_resource *resource);
+int lib_interface_isis_ipv4_routing_modify(enum nb_event event,
+					   const struct lyd_node *dnode,
+					   union nb_resource *resource);
+int lib_interface_isis_ipv6_routing_modify(enum nb_event event,
+					   const struct lyd_node *dnode,
+					   union nb_resource *resource);
+int lib_interface_isis_circuit_type_modify(enum nb_event event,
+					   const struct lyd_node *dnode,
+					   union nb_resource *resource);
+int lib_interface_isis_bfd_monitoring_modify(enum nb_event event,
+					     const struct lyd_node *dnode,
+					     union nb_resource *resource);
+int lib_interface_isis_csnp_interval_level_1_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int lib_interface_isis_csnp_interval_level_2_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int lib_interface_isis_psnp_interval_level_1_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int lib_interface_isis_psnp_interval_level_2_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int lib_interface_isis_hello_padding_modify(enum nb_event event,
+					    const struct lyd_node *dnode,
+					    union nb_resource *resource);
+int lib_interface_isis_hello_interval_level_1_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int lib_interface_isis_hello_interval_level_2_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int lib_interface_isis_hello_multiplier_level_1_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int lib_interface_isis_hello_multiplier_level_2_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int lib_interface_isis_metric_level_1_modify(enum nb_event event,
+					     const struct lyd_node *dnode,
+					     union nb_resource *resource);
+int lib_interface_isis_metric_level_2_modify(enum nb_event event,
+					     const struct lyd_node *dnode,
+					     union nb_resource *resource);
+int lib_interface_isis_priority_level_1_modify(enum nb_event event,
+					       const struct lyd_node *dnode,
+					       union nb_resource *resource);
+int lib_interface_isis_priority_level_2_modify(enum nb_event event,
+					       const struct lyd_node *dnode,
+					       union nb_resource *resource);
+int lib_interface_isis_network_type_modify(enum nb_event event,
+					   const struct lyd_node *dnode,
+					   union nb_resource *resource);
+int lib_interface_isis_passive_modify(enum nb_event event,
+				      const struct lyd_node *dnode,
+				      union nb_resource *resource);
+int lib_interface_isis_password_create(enum nb_event event,
+				       const struct lyd_node *dnode,
+				       union nb_resource *resource);
+int lib_interface_isis_password_destroy(enum nb_event event,
+					const struct lyd_node *dnode);
+int lib_interface_isis_password_password_modify(enum nb_event event,
+						const struct lyd_node *dnode,
+						union nb_resource *resource);
+int lib_interface_isis_password_password_type_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int lib_interface_isis_disable_three_way_handshake_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int lib_interface_isis_multi_topology_ipv4_unicast_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int lib_interface_isis_multi_topology_ipv4_multicast_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int lib_interface_isis_multi_topology_ipv4_management_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int lib_interface_isis_multi_topology_ipv6_unicast_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int lib_interface_isis_multi_topology_ipv6_multicast_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int lib_interface_isis_multi_topology_ipv6_management_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+int lib_interface_isis_multi_topology_ipv6_dstsrc_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource);
+const void *
+lib_interface_isis_adjacencies_adjacency_get_next(const void *parent_list_entry,
+						  const void *list_entry);
+struct yang_data *
+lib_interface_isis_adjacencies_adjacency_neighbor_sys_type_get_elem(
+	const char *xpath, const void *list_entry);
+struct yang_data *
+lib_interface_isis_adjacencies_adjacency_neighbor_sysid_get_elem(
+	const char *xpath, const void *list_entry);
+struct yang_data *
+lib_interface_isis_adjacencies_adjacency_neighbor_extended_circuit_id_get_elem(
+	const char *xpath, const void *list_entry);
+struct yang_data *
+lib_interface_isis_adjacencies_adjacency_neighbor_snpa_get_elem(
+	const char *xpath, const void *list_entry);
+struct yang_data *lib_interface_isis_adjacencies_adjacency_hold_timer_get_elem(
+	const char *xpath, const void *list_entry);
+struct yang_data *
+lib_interface_isis_adjacencies_adjacency_neighbor_priority_get_elem(
+	const char *xpath, const void *list_entry);
+struct yang_data *
+lib_interface_isis_adjacencies_adjacency_state_get_elem(const char *xpath,
+							const void *list_entry);
+struct yang_data *lib_interface_isis_event_counters_adjacency_changes_get_elem(
+	const char *xpath, const void *list_entry);
+struct yang_data *lib_interface_isis_event_counters_adjacency_number_get_elem(
+	const char *xpath, const void *list_entry);
+struct yang_data *
+lib_interface_isis_event_counters_init_fails_get_elem(const char *xpath,
+						      const void *list_entry);
+struct yang_data *lib_interface_isis_event_counters_adjacency_rejects_get_elem(
+	const char *xpath, const void *list_entry);
+struct yang_data *lib_interface_isis_event_counters_id_len_mismatch_get_elem(
+	const char *xpath, const void *list_entry);
+struct yang_data *
+lib_interface_isis_event_counters_max_area_addresses_mismatch_get_elem(
+	const char *xpath, const void *list_entry);
+struct yang_data *
+lib_interface_isis_event_counters_authentication_type_fails_get_elem(
+	const char *xpath, const void *list_entry);
+struct yang_data *
+lib_interface_isis_event_counters_authentication_fails_get_elem(
+	const char *xpath, const void *list_entry);
+
+/* Optional 'apply_finish' callbacks. */
+void ietf_backoff_delay_apply_finish(const struct lyd_node *dnode);
+void area_password_apply_finish(const struct lyd_node *dnode);
+void domain_password_apply_finish(const struct lyd_node *dnode);
+void default_info_origin_apply_finish(const struct lyd_node *dnode, int family);
+void default_info_origin_ipv4_apply_finish(const struct lyd_node *dnode);
+void default_info_origin_ipv6_apply_finish(const struct lyd_node *dnode);
+void redistribute_apply_finish(const struct lyd_node *dnode, int family);
+void redistribute_ipv4_apply_finish(const struct lyd_node *dnode);
+void redistribute_ipv6_apply_finish(const struct lyd_node *dnode);
+
+/* Optional 'cli_show' callbacks. */
+void cli_show_router_isis(struct vty *vty, struct lyd_node *dnode,
+			  bool show_defaults);
+void cli_show_ip_isis_ipv4(struct vty *vty, struct lyd_node *dnode,
+			   bool show_defaults);
+void cli_show_ip_isis_ipv6(struct vty *vty, struct lyd_node *dnode,
+			   bool show_defaults);
+void cli_show_ip_isis_bfd_monitoring(struct vty *vty, struct lyd_node *dnode,
+				     bool show_defaults);
+void cli_show_isis_area_address(struct vty *vty, struct lyd_node *dnode,
+				bool show_defaults);
+void cli_show_isis_is_type(struct vty *vty, struct lyd_node *dnode,
+			   bool show_defaults);
+void cli_show_isis_dynamic_hostname(struct vty *vty, struct lyd_node *dnode,
+				    bool show_defaults);
+void cli_show_isis_attached(struct vty *vty, struct lyd_node *dnode,
+			    bool show_defaults);
+void cli_show_isis_overload(struct vty *vty, struct lyd_node *dnode,
+			    bool show_defaults);
+void cli_show_isis_metric_style(struct vty *vty, struct lyd_node *dnode,
+				bool show_defaults);
+void cli_show_isis_area_pwd(struct vty *vty, struct lyd_node *dnode,
+			    bool show_defaults);
+void cli_show_isis_domain_pwd(struct vty *vty, struct lyd_node *dnode,
+			      bool show_defaults);
+void cli_show_isis_lsp_gen_interval(struct vty *vty, struct lyd_node *dnode,
+				    bool show_defaults);
+void cli_show_isis_lsp_ref_interval(struct vty *vty, struct lyd_node *dnode,
+				    bool show_defaults);
+void cli_show_isis_lsp_max_lifetime(struct vty *vty, struct lyd_node *dnode,
+				    bool show_defaults);
+void cli_show_isis_lsp_mtu(struct vty *vty, struct lyd_node *dnode,
+			   bool show_defaults);
+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_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,
+			   bool show_defaults);
+void cli_show_isis_mpls_te_router_addr(struct vty *vty, struct lyd_node *dnode,
+				       bool show_defaults);
+void cli_show_isis_def_origin_ipv4(struct vty *vty, struct lyd_node *dnode,
+				   bool show_defaults);
+void cli_show_isis_def_origin_ipv6(struct vty *vty, struct lyd_node *dnode,
+				   bool show_defaults);
+void cli_show_isis_redistribute_ipv4(struct vty *vty, struct lyd_node *dnode,
+				     bool show_defaults);
+void cli_show_isis_redistribute_ipv6(struct vty *vty, struct lyd_node *dnode,
+				     bool show_defaults);
+void cli_show_isis_mt_ipv4_multicast(struct vty *vty, struct lyd_node *dnode,
+				     bool show_defaults);
+void cli_show_isis_mt_ipv4_mgmt(struct vty *vty, struct lyd_node *dnode,
+				bool show_defaults);
+void cli_show_isis_mt_ipv6_unicast(struct vty *vty, struct lyd_node *dnode,
+				   bool show_defaults);
+void cli_show_isis_mt_ipv6_multicast(struct vty *vty, struct lyd_node *dnode,
+				     bool show_defaults);
+void cli_show_isis_mt_ipv6_mgmt(struct vty *vty, struct lyd_node *dnode,
+				bool show_defaults);
+void cli_show_isis_mt_ipv6_dstsrc(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,
+			       bool show_defaults);
+void cli_show_ip_isis_metric(struct vty *vty, struct lyd_node *dnode,
+			     bool show_defaults);
+void cli_show_ip_isis_hello_interval(struct vty *vty, struct lyd_node *dnode,
+				     bool show_defaults);
+void cli_show_ip_isis_hello_multi(struct vty *vty, struct lyd_node *dnode,
+				  bool show_defaults);
+void cli_show_ip_isis_threeway_shake(struct vty *vty, struct lyd_node *dnode,
+				     bool show_defaults);
+void cli_show_ip_isis_hello_padding(struct vty *vty, struct lyd_node *dnode,
+				    bool show_defaults);
+void cli_show_ip_isis_csnp_interval(struct vty *vty, struct lyd_node *dnode,
+				    bool show_defaults);
+void cli_show_ip_isis_psnp_interval(struct vty *vty, struct lyd_node *dnode,
+				    bool show_defaults);
+void cli_show_ip_isis_mt_ipv4_unicast(struct vty *vty, struct lyd_node *dnode,
+				      bool show_defaults);
+void cli_show_ip_isis_mt_ipv4_multicast(struct vty *vty, struct lyd_node *dnode,
+					bool show_defaults);
+void cli_show_ip_isis_mt_ipv4_mgmt(struct vty *vty, struct lyd_node *dnode,
+				   bool show_defaults);
+void cli_show_ip_isis_mt_ipv6_unicast(struct vty *vty, struct lyd_node *dnode,
+				      bool show_defaults);
+void cli_show_ip_isis_mt_ipv6_multicast(struct vty *vty, struct lyd_node *dnode,
+					bool show_defaults);
+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_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,
+				   bool show_defaults);
+void cli_show_ip_isis_priority(struct vty *vty, struct lyd_node *dnode,
+			       bool show_defaults);
+void cli_show_isis_log_adjacency(struct vty *vty, struct lyd_node *dnode,
+				 bool show_defaults);
+
+/* Notifications. */
+void isis_notif_db_overload(const struct isis_area *area, bool overload);
+void isis_notif_lsp_too_large(const struct isis_circuit *circuit,
+			      uint32_t pdu_size, const char *lsp_id);
+void isis_notif_if_state_change(const struct isis_circuit *circuit, bool down);
+void isis_notif_corrupted_lsp(const struct isis_area *area,
+			      const char *lsp_id); /* currently unused */
+void isis_notif_lsp_exceed_max(const struct isis_area *area,
+			       const char *lsp_id);
+void isis_notif_max_area_addr_mismatch(const struct isis_circuit *circuit,
+				       uint8_t max_area_addrs,
+				       const char *raw_pdu);
+void isis_notif_authentication_type_failure(const struct isis_circuit *circuit,
+					    const char *raw_pdu);
+void isis_notif_authentication_failure(const struct isis_circuit *circuit,
+				       const char *raw_pdu);
+void isis_notif_adj_state_change(const struct isis_adjacency *adj,
+				 int new_state, const char *reason);
+void isis_notif_reject_adjacency(const struct isis_circuit *circuit,
+				 const char *reason, const char *raw_pdu);
+void isis_notif_area_mismatch(const struct isis_circuit *circuit,
+			      const char *raw_pdu);
+void isis_notif_lsp_received(const struct isis_circuit *circuit,
+			     const char *lsp_id, uint32_t seqno,
+			     uint32_t timestamp, const char *sys_id);
+void isis_notif_lsp_gen(const struct isis_area *area, const char *lsp_id,
+			uint32_t seqno, uint32_t timestamp);
+void isis_notif_id_len_mismatch(const struct isis_circuit *circuit,
+				uint8_t rcv_id_len, const char *raw_pdu);
+void isis_notif_version_skew(const struct isis_circuit *circuit,
+			     uint8_t version, const char *raw_pdu);
+void isis_notif_lsp_error(const struct isis_circuit *circuit,
+			  const char *lsp_id, const char *raw_pdu,
+			  uint32_t offset, uint8_t tlv_type);
+void isis_notif_seqno_skipped(const struct isis_circuit *circuit,
+			      const char *lsp_id);
+void isis_notif_own_lsp_purge(const struct isis_circuit *circuit,
+			      const char *lsp_id);
+
+#endif /* ISISD_ISIS_NB_H_ */
diff --git a/isisd/isis_nb_config.c b/isisd/isis_nb_config.c
new file mode 100644
index 000000000..820cfaa42
--- /dev/null
+++ b/isisd/isis_nb_config.c
@@ -0,0 +1,2236 @@
+/*
+ * Copyright (C) 2001,2002   Sampo Saaristo
+ *                           Tampere University of Technology
+ *                           Institute of Communications Engineering
+ * Copyright (C) 2018        Volta Networks
+ *                           Emanuele Di Pascale
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; see the file COPYING; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <zebra.h>
+
+#include "northbound.h"
+#include "linklist.h"
+#include "log.h"
+#include "bfd.h"
+#include "spf_backoff.h"
+#include "lib_errors.h"
+#include "vrf.h"
+
+#include "isisd/isisd.h"
+#include "isisd/isis_nb.h"
+#include "isisd/isis_common.h"
+#include "isisd/isis_bfd.h"
+#include "isisd/isis_circuit.h"
+#include "isisd/isis_lsp.h"
+#include "isisd/isis_dynhn.h"
+#include "isisd/isis_misc.h"
+#include "isisd/isis_csm.h"
+#include "isisd/isis_adjacency.h"
+#include "isisd/isis_spf.h"
+#include "isisd/isis_te.h"
+#include "isisd/isis_memory.h"
+#include "isisd/isis_mt.h"
+#include "isisd/isis_redist.h"
+
+/*
+ * XPath: /frr-isisd:isis/instance
+ */
+int isis_instance_create(enum nb_event event, const struct lyd_node *dnode,
+			 union nb_resource *resource)
+{
+	struct isis_area *area;
+	const char *area_tag;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	area_tag = yang_dnode_get_string(dnode, "./area-tag");
+	area = isis_area_lookup(area_tag);
+	if (area)
+		return NB_ERR_INCONSISTENCY;
+
+	area = isis_area_create(area_tag);
+	/* save area in dnode to avoid looking it up all the time */
+	nb_running_set_entry(dnode, area);
+
+	return NB_OK;
+}
+
+int isis_instance_destroy(enum nb_event event, const struct lyd_node *dnode)
+{
+	struct isis_area *area;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_unset_entry(dnode);
+	isis_area_destroy(area->area_tag);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/is-type
+ */
+int isis_instance_is_type_modify(enum nb_event event,
+				 const struct lyd_node *dnode,
+				 union nb_resource *resource)
+{
+	struct isis_area *area;
+	int type;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_get_entry(dnode, NULL, true);
+	type = yang_dnode_get_enum(dnode, NULL);
+	isis_area_is_type_set(area, type);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/area-address
+ */
+int isis_instance_area_address_create(enum nb_event event,
+				      const struct lyd_node *dnode,
+				      union nb_resource *resource)
+{
+	struct isis_area *area;
+	struct area_addr addr, *addrr = NULL, *addrp = NULL;
+	struct listnode *node;
+	uint8_t buff[255];
+	const char *net_title = yang_dnode_get_string(dnode, NULL);
+
+	switch (event) {
+	case NB_EV_VALIDATE:
+		addr.addr_len = dotformat2buff(buff, net_title);
+		memcpy(addr.area_addr, buff, addr.addr_len);
+		if (addr.area_addr[addr.addr_len - 1] != 0) {
+			flog_warn(
+				EC_LIB_NB_CB_CONFIG_VALIDATE,
+				"nsel byte (last byte) in area address must be 0");
+			return NB_ERR_VALIDATION;
+		}
+		if (isis->sysid_set) {
+			/* Check that the SystemID portions match */
+			if (memcmp(isis->sysid, GETSYSID((&addr)),
+				   ISIS_SYS_ID_LEN)) {
+				flog_warn(
+					EC_LIB_NB_CB_CONFIG_VALIDATE,
+					"System ID must not change when defining additional area addresses");
+				return NB_ERR_VALIDATION;
+			}
+		}
+		break;
+	case NB_EV_PREPARE:
+		addrr = XMALLOC(MTYPE_ISIS_AREA_ADDR, sizeof(struct area_addr));
+		addrr->addr_len = dotformat2buff(buff, net_title);
+		memcpy(addrr->area_addr, buff, addrr->addr_len);
+		resource->ptr = addrr;
+		break;
+	case NB_EV_ABORT:
+		XFREE(MTYPE_ISIS_AREA_ADDR, resource->ptr);
+		break;
+	case NB_EV_APPLY:
+		area = nb_running_get_entry(dnode, NULL, true);
+		addrr = resource->ptr;
+
+		if (isis->sysid_set == 0) {
+			/*
+			 * First area address - get the SystemID for this router
+			 */
+			memcpy(isis->sysid, GETSYSID(addrr), ISIS_SYS_ID_LEN);
+			isis->sysid_set = 1;
+		} else {
+			/* check that we don't already have this address */
+			for (ALL_LIST_ELEMENTS_RO(area->area_addrs, node,
+						  addrp)) {
+				if ((addrp->addr_len + ISIS_SYS_ID_LEN
+				     + ISIS_NSEL_LEN)
+				    != (addrr->addr_len))
+					continue;
+				if (!memcmp(addrp->area_addr, addrr->area_addr,
+					    addrr->addr_len)) {
+					XFREE(MTYPE_ISIS_AREA_ADDR, addrr);
+					return NB_OK; /* silent fail */
+				}
+			}
+		}
+
+		/*Forget the systemID part of the address */
+		addrr->addr_len -= (ISIS_SYS_ID_LEN + ISIS_NSEL_LEN);
+		assert(area->area_addrs); /* to silence scan-build sillyness */
+		listnode_add(area->area_addrs, addrr);
+
+		/* only now we can safely generate our LSPs for this area */
+		if (listcount(area->area_addrs) > 0) {
+			if (area->is_type & IS_LEVEL_1)
+				lsp_generate(area, IS_LEVEL_1);
+			if (area->is_type & IS_LEVEL_2)
+				lsp_generate(area, IS_LEVEL_2);
+		}
+		break;
+	}
+
+	return NB_OK;
+}
+
+int isis_instance_area_address_destroy(enum nb_event event,
+				       const struct lyd_node *dnode)
+{
+	struct area_addr addr, *addrp = NULL;
+	struct listnode *node;
+	uint8_t buff[255];
+	struct isis_area *area;
+	const char *net_title;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	net_title = yang_dnode_get_string(dnode, NULL);
+	addr.addr_len = dotformat2buff(buff, net_title);
+	memcpy(addr.area_addr, buff, (int)addr.addr_len);
+	area = nb_running_get_entry(dnode, NULL, true);
+	for (ALL_LIST_ELEMENTS_RO(area->area_addrs, node, addrp)) {
+		if ((addrp->addr_len + ISIS_SYS_ID_LEN + 1) == addr.addr_len
+		    && !memcmp(addrp->area_addr, addr.area_addr, addr.addr_len))
+			break;
+	}
+	if (!addrp)
+		return NB_ERR_INCONSISTENCY;
+
+	listnode_delete(area->area_addrs, addrp);
+	XFREE(MTYPE_ISIS_AREA_ADDR, addrp);
+	/*
+	 * Last area address - reset the SystemID for this router
+	 */
+	if (listcount(area->area_addrs) == 0) {
+		memset(isis->sysid, 0, ISIS_SYS_ID_LEN);
+		isis->sysid_set = 0;
+		if (isis->debugs & DEBUG_EVENTS)
+			zlog_debug("Router has no SystemID");
+	}
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/dynamic-hostname
+ */
+int isis_instance_dynamic_hostname_modify(enum nb_event event,
+					  const struct lyd_node *dnode,
+					  union nb_resource *resource)
+{
+	struct isis_area *area;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_get_entry(dnode, NULL, true);
+	isis_area_dynhostname_set(area, yang_dnode_get_bool(dnode, NULL));
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/attached
+ */
+int isis_instance_attached_modify(enum nb_event event,
+				  const struct lyd_node *dnode,
+				  union nb_resource *resource)
+{
+	struct isis_area *area;
+	bool attached;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_get_entry(dnode, NULL, true);
+	attached = yang_dnode_get_bool(dnode, NULL);
+	isis_area_attached_bit_set(area, attached);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/overload
+ */
+int isis_instance_overload_modify(enum nb_event event,
+				  const struct lyd_node *dnode,
+				  union nb_resource *resource)
+{
+	struct isis_area *area;
+	bool overload;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_get_entry(dnode, NULL, true);
+	overload = yang_dnode_get_bool(dnode, NULL);
+	isis_area_overload_bit_set(area, overload);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/metric-style
+ */
+int isis_instance_metric_style_modify(enum nb_event event,
+				      const struct lyd_node *dnode,
+				      union nb_resource *resource)
+{
+	struct isis_area *area;
+	bool old_metric, new_metric;
+	enum isis_metric_style metric_style = yang_dnode_get_enum(dnode, NULL);
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_get_entry(dnode, NULL, true);
+	old_metric = (metric_style == ISIS_WIDE_METRIC) ? false : true;
+	new_metric = (metric_style == ISIS_NARROW_METRIC) ? false : true;
+	isis_area_metricstyle_set(area, old_metric, new_metric);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/purge-originator
+ */
+int isis_instance_purge_originator_modify(enum nb_event event,
+					  const struct lyd_node *dnode,
+					  union nb_resource *resource)
+{
+	struct isis_area *area;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_get_entry(dnode, NULL, true);
+	area->purge_originator = yang_dnode_get_bool(dnode, NULL);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/lsp/mtu
+ */
+int isis_instance_lsp_mtu_modify(enum nb_event event,
+				 const struct lyd_node *dnode,
+				 union nb_resource *resource)
+{
+	struct listnode *node;
+	struct isis_circuit *circuit;
+	uint16_t lsp_mtu = yang_dnode_get_uint16(dnode, NULL);
+	struct isis_area *area;
+
+	switch (event) {
+	case NB_EV_VALIDATE:
+		area = nb_running_get_entry(dnode, NULL, false);
+		if (!area)
+			break;
+		for (ALL_LIST_ELEMENTS_RO(area->circuit_list, node, circuit)) {
+			if (circuit->state != C_STATE_INIT
+			    && circuit->state != C_STATE_UP)
+				continue;
+			if (lsp_mtu > isis_circuit_pdu_size(circuit)) {
+				flog_warn(
+					EC_LIB_NB_CB_CONFIG_VALIDATE,
+					"ISIS area contains circuit %s, which has a maximum PDU size of %zu",
+					circuit->interface->name,
+					isis_circuit_pdu_size(circuit));
+				return NB_ERR_VALIDATION;
+			}
+		}
+		break;
+	case NB_EV_PREPARE:
+	case NB_EV_ABORT:
+		break;
+	case NB_EV_APPLY:
+		area = nb_running_get_entry(dnode, NULL, true);
+		isis_area_lsp_mtu_set(area, lsp_mtu);
+		break;
+	}
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/lsp/refresh-interval/level-1
+ */
+int isis_instance_lsp_refresh_interval_level_1_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	struct isis_area *area;
+	uint16_t refr_int;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	refr_int = yang_dnode_get_uint16(dnode, NULL);
+	area = nb_running_get_entry(dnode, NULL, true);
+	isis_area_lsp_refresh_set(area, IS_LEVEL_1, refr_int);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/lsp/refresh-interval/level-2
+ */
+int isis_instance_lsp_refresh_interval_level_2_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	struct isis_area *area;
+	uint16_t refr_int;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	refr_int = yang_dnode_get_uint16(dnode, NULL);
+	area = nb_running_get_entry(dnode, NULL, true);
+	isis_area_lsp_refresh_set(area, IS_LEVEL_2, refr_int);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/lsp/maximum-lifetime/level-1
+ */
+int isis_instance_lsp_maximum_lifetime_level_1_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	struct isis_area *area;
+	uint16_t max_lt;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	max_lt = yang_dnode_get_uint16(dnode, NULL);
+	area = nb_running_get_entry(dnode, NULL, true);
+	isis_area_max_lsp_lifetime_set(area, IS_LEVEL_1, max_lt);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/lsp/maximum-lifetime/level-2
+ */
+int isis_instance_lsp_maximum_lifetime_level_2_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	struct isis_area *area;
+	uint16_t max_lt;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	max_lt = yang_dnode_get_uint16(dnode, NULL);
+	area = nb_running_get_entry(dnode, NULL, true);
+	isis_area_max_lsp_lifetime_set(area, IS_LEVEL_2, max_lt);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/lsp/generation-interval/level-1
+ */
+int isis_instance_lsp_generation_interval_level_1_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	struct isis_area *area;
+	uint16_t gen_int;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	gen_int = yang_dnode_get_uint16(dnode, NULL);
+	area = nb_running_get_entry(dnode, NULL, true);
+	area->lsp_gen_interval[0] = gen_int;
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/lsp/generation-interval/level-2
+ */
+int isis_instance_lsp_generation_interval_level_2_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	struct isis_area *area;
+	uint16_t gen_int;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	gen_int = yang_dnode_get_uint16(dnode, NULL);
+	area = nb_running_get_entry(dnode, NULL, true);
+	area->lsp_gen_interval[1] = gen_int;
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/spf/ietf-backoff-delay
+ */
+void ietf_backoff_delay_apply_finish(const struct lyd_node *dnode)
+{
+	long init_delay = yang_dnode_get_uint16(dnode, "./init-delay");
+	long short_delay = yang_dnode_get_uint16(dnode, "./short-delay");
+	long long_delay = yang_dnode_get_uint16(dnode, "./long-delay");
+	long holddown = yang_dnode_get_uint16(dnode, "./hold-down");
+	long timetolearn = yang_dnode_get_uint16(dnode, "./time-to-learn");
+	struct isis_area *area = nb_running_get_entry(dnode, NULL, true);
+	size_t bufsiz = strlen(area->area_tag) + sizeof("IS-IS  Lx");
+	char *buf = XCALLOC(MTYPE_TMP, bufsiz);
+
+	snprintf(buf, bufsiz, "IS-IS %s L1", area->area_tag);
+	spf_backoff_free(area->spf_delay_ietf[0]);
+	area->spf_delay_ietf[0] =
+		spf_backoff_new(master, buf, init_delay, short_delay,
+				long_delay, holddown, timetolearn);
+
+	snprintf(buf, bufsiz, "IS-IS %s L2", area->area_tag);
+	spf_backoff_free(area->spf_delay_ietf[1]);
+	area->spf_delay_ietf[1] =
+		spf_backoff_new(master, buf, init_delay, short_delay,
+				long_delay, holddown, timetolearn);
+
+	XFREE(MTYPE_TMP, buf);
+}
+
+int isis_instance_spf_ietf_backoff_delay_create(enum nb_event event,
+						const struct lyd_node *dnode,
+						union nb_resource *resource)
+{
+	/* All the work is done in the apply_finish */
+	return NB_OK;
+}
+
+int isis_instance_spf_ietf_backoff_delay_destroy(enum nb_event event,
+						 const struct lyd_node *dnode)
+{
+	struct isis_area *area;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_get_entry(dnode, NULL, true);
+	spf_backoff_free(area->spf_delay_ietf[0]);
+	spf_backoff_free(area->spf_delay_ietf[1]);
+	area->spf_delay_ietf[0] = NULL;
+	area->spf_delay_ietf[1] = NULL;
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/spf/ietf-backoff-delay/init-delay
+ */
+int isis_instance_spf_ietf_backoff_delay_init_delay_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	/* All the work is done in the apply_finish */
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/spf/ietf-backoff-delay/short-delay
+ */
+int isis_instance_spf_ietf_backoff_delay_short_delay_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	/* All the work is done in the apply_finish */
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/spf/ietf-backoff-delay/long-delay
+ */
+int isis_instance_spf_ietf_backoff_delay_long_delay_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	/* All the work is done in the apply_finish */
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/spf/ietf-backoff-delay/hold-down
+ */
+int isis_instance_spf_ietf_backoff_delay_hold_down_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	/* All the work is done in the apply_finish */
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/spf/ietf-backoff-delay/time-to-learn
+ */
+int isis_instance_spf_ietf_backoff_delay_time_to_learn_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	/* All the work is done in the apply_finish */
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/spf/minimum-interval/level-1
+ */
+int isis_instance_spf_minimum_interval_level_1_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	struct isis_area *area;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_get_entry(dnode, NULL, true);
+	area->min_spf_interval[0] = yang_dnode_get_uint16(dnode, NULL);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/spf/minimum-interval/level-2
+ */
+int isis_instance_spf_minimum_interval_level_2_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	struct isis_area *area;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_get_entry(dnode, NULL, true);
+	area->min_spf_interval[1] = yang_dnode_get_uint16(dnode, NULL);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/area-password
+ */
+void area_password_apply_finish(const struct lyd_node *dnode)
+{
+	const char *password = yang_dnode_get_string(dnode, "./password");
+	struct isis_area *area = nb_running_get_entry(dnode, NULL, true);
+	int pass_type = yang_dnode_get_enum(dnode, "./password-type");
+	uint8_t snp_auth = yang_dnode_get_enum(dnode, "./authenticate-snp");
+
+	switch (pass_type) {
+	case ISIS_PASSWD_TYPE_CLEARTXT:
+		isis_area_passwd_cleartext_set(area, IS_LEVEL_1, password,
+					       snp_auth);
+		break;
+	case ISIS_PASSWD_TYPE_HMAC_MD5:
+		isis_area_passwd_hmac_md5_set(area, IS_LEVEL_1, password,
+					      snp_auth);
+		break;
+	}
+}
+
+int isis_instance_area_password_create(enum nb_event event,
+				       const struct lyd_node *dnode,
+				       union nb_resource *resource)
+{
+	/* actual setting is done in apply_finish */
+	return NB_OK;
+}
+
+int isis_instance_area_password_destroy(enum nb_event event,
+					const struct lyd_node *dnode)
+{
+	struct isis_area *area;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_get_entry(dnode, NULL, true);
+	isis_area_passwd_unset(area, IS_LEVEL_1);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/area-password/password
+ */
+int isis_instance_area_password_password_modify(enum nb_event event,
+						const struct lyd_node *dnode,
+						union nb_resource *resource)
+{
+	/* actual setting is done in apply_finish */
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/area-password/password-type
+ */
+int isis_instance_area_password_password_type_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	/* actual setting is done in apply_finish */
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/area-password/authenticate-snp
+ */
+int isis_instance_area_password_authenticate_snp_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	/* actual setting is done in apply_finish */
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/domain-password
+ */
+void domain_password_apply_finish(const struct lyd_node *dnode)
+{
+	const char *password = yang_dnode_get_string(dnode, "./password");
+	struct isis_area *area = nb_running_get_entry(dnode, NULL, true);
+	int pass_type = yang_dnode_get_enum(dnode, "./password-type");
+	uint8_t snp_auth = yang_dnode_get_enum(dnode, "./authenticate-snp");
+
+	switch (pass_type) {
+	case ISIS_PASSWD_TYPE_CLEARTXT:
+		isis_area_passwd_cleartext_set(area, IS_LEVEL_2, password,
+					       snp_auth);
+		break;
+	case ISIS_PASSWD_TYPE_HMAC_MD5:
+		isis_area_passwd_hmac_md5_set(area, IS_LEVEL_2, password,
+					      snp_auth);
+		break;
+	}
+}
+
+int isis_instance_domain_password_create(enum nb_event event,
+					 const struct lyd_node *dnode,
+					 union nb_resource *resource)
+{
+	/* actual setting is done in apply_finish */
+	return NB_OK;
+}
+
+int isis_instance_domain_password_destroy(enum nb_event event,
+					  const struct lyd_node *dnode)
+{
+	struct isis_area *area;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_get_entry(dnode, NULL, true);
+	isis_area_passwd_unset(area, IS_LEVEL_2);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/domain-password/password
+ */
+int isis_instance_domain_password_password_modify(enum nb_event event,
+						  const struct lyd_node *dnode,
+						  union nb_resource *resource)
+{
+	/* actual setting is done in apply_finish */
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/domain-password/password-type
+ */
+int isis_instance_domain_password_password_type_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	/* actual setting is done in apply_finish */
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/domain-password/authenticate-snp
+ */
+int isis_instance_domain_password_authenticate_snp_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	/* actual setting is done in apply_finish */
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/default-information-originate/ipv4
+ */
+void default_info_origin_apply_finish(const struct lyd_node *dnode, int family)
+{
+	int originate_type = DEFAULT_ORIGINATE;
+	unsigned long metric = 0;
+	const char *routemap = NULL;
+	struct isis_area *area = nb_running_get_entry(dnode, NULL, true);
+	int level = yang_dnode_get_enum(dnode, "./level");
+
+	if (yang_dnode_get_bool(dnode, "./always")) {
+		originate_type = DEFAULT_ORIGINATE_ALWAYS;
+	} else if (family == AF_INET6) {
+		zlog_warn(
+			"%s: Zebra doesn't implement default-originate for IPv6 yet, so use with care or use default-originate always.",
+			__func__);
+	}
+
+	if (yang_dnode_exists(dnode, "./metric"))
+		metric = yang_dnode_get_uint32(dnode, "./metric");
+	if (yang_dnode_exists(dnode, "./route-map"))
+		routemap = yang_dnode_get_string(dnode, "./route-map");
+
+	isis_redist_set(area, level, family, DEFAULT_ROUTE, metric, routemap,
+			originate_type);
+}
+
+void default_info_origin_ipv4_apply_finish(const struct lyd_node *dnode)
+{
+	default_info_origin_apply_finish(dnode, AF_INET);
+}
+
+void default_info_origin_ipv6_apply_finish(const struct lyd_node *dnode)
+{
+	default_info_origin_apply_finish(dnode, AF_INET6);
+}
+
+int isis_instance_default_information_originate_ipv4_create(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	/* It's all done by default_info_origin_apply_finish */
+	return NB_OK;
+}
+
+int isis_instance_default_information_originate_ipv4_destroy(
+	enum nb_event event, const struct lyd_node *dnode)
+{
+	struct isis_area *area;
+	int level;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_get_entry(dnode, NULL, true);
+	level = yang_dnode_get_enum(dnode, "./level");
+	isis_redist_unset(area, level, AF_INET, DEFAULT_ROUTE);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/default-information-originate/ipv4/always
+ */
+int isis_instance_default_information_originate_ipv4_always_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	/* It's all done by default_info_origin_apply_finish */
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/default-information-originate/ipv4/route-map
+ */
+int isis_instance_default_information_originate_ipv4_route_map_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	/* It's all done by default_info_origin_apply_finish */
+	return NB_OK;
+}
+
+int isis_instance_default_information_originate_ipv4_route_map_destroy(
+	enum nb_event event, const struct lyd_node *dnode)
+{
+	/* It's all done by default_info_origin_apply_finish */
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/default-information-originate/ipv4/metric
+ */
+int isis_instance_default_information_originate_ipv4_metric_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	/* It's all done by default_info_origin_apply_finish */
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/default-information-originate/ipv6
+ */
+int isis_instance_default_information_originate_ipv6_create(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	/* It's all done by default_info_origin_apply_finish */
+	return NB_OK;
+}
+
+int isis_instance_default_information_originate_ipv6_destroy(
+	enum nb_event event, const struct lyd_node *dnode)
+{
+	struct isis_area *area;
+	int level;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_get_entry(dnode, NULL, true);
+	level = yang_dnode_get_enum(dnode, "./level");
+	isis_redist_unset(area, level, AF_INET6, DEFAULT_ROUTE);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/default-information-originate/ipv6/always
+ */
+int isis_instance_default_information_originate_ipv6_always_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	/* It's all done by default_info_origin_apply_finish */
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/default-information-originate/ipv6/route-map
+ */
+int isis_instance_default_information_originate_ipv6_route_map_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	/* It's all done by default_info_origin_apply_finish */
+	return NB_OK;
+}
+
+int isis_instance_default_information_originate_ipv6_route_map_destroy(
+	enum nb_event event, const struct lyd_node *dnode)
+{
+	/* It's all done by default_info_origin_apply_finish */
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/default-information-originate/ipv6/metric
+ */
+int isis_instance_default_information_originate_ipv6_metric_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	/* It's all done by default_info_origin_apply_finish */
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/redistribute/ipv4
+ */
+void redistribute_apply_finish(const struct lyd_node *dnode, int family)
+{
+	assert(family == AF_INET || family == AF_INET6);
+	int type, level;
+	unsigned long metric = 0;
+	const char *routemap = NULL;
+	struct isis_area *area;
+
+	type = yang_dnode_get_enum(dnode, "./protocol");
+	level = yang_dnode_get_enum(dnode, "./level");
+	area = nb_running_get_entry(dnode, NULL, true);
+
+	if (yang_dnode_exists(dnode, "./metric"))
+		metric = yang_dnode_get_uint32(dnode, "./metric");
+	if (yang_dnode_exists(dnode, "./route-map"))
+		routemap = yang_dnode_get_string(dnode, "./route-map");
+
+	isis_redist_set(area, level, family, type, metric, routemap, 0);
+}
+
+void redistribute_ipv4_apply_finish(const struct lyd_node *dnode)
+{
+	redistribute_apply_finish(dnode, AF_INET);
+}
+
+void redistribute_ipv6_apply_finish(const struct lyd_node *dnode)
+{
+	redistribute_apply_finish(dnode, AF_INET6);
+}
+
+int isis_instance_redistribute_ipv4_create(enum nb_event event,
+					   const struct lyd_node *dnode,
+					   union nb_resource *resource)
+{
+	/* It's all done by redistribute_apply_finish */
+	return NB_OK;
+}
+
+int isis_instance_redistribute_ipv4_destroy(enum nb_event event,
+					    const struct lyd_node *dnode)
+{
+	struct isis_area *area;
+	int level, type;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_get_entry(dnode, NULL, true);
+	level = yang_dnode_get_enum(dnode, "./level");
+	type = yang_dnode_get_enum(dnode, "./protocol");
+	isis_redist_unset(area, level, AF_INET, type);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/redistribute/ipv4/route-map
+ */
+int isis_instance_redistribute_ipv4_route_map_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	/* It's all done by redistribute_apply_finish */
+	return NB_OK;
+}
+
+int isis_instance_redistribute_ipv4_route_map_destroy(
+	enum nb_event event, const struct lyd_node *dnode)
+{
+	/* It's all done by redistribute_apply_finish */
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/redistribute/ipv4/metric
+ */
+int isis_instance_redistribute_ipv4_metric_modify(enum nb_event event,
+						  const struct lyd_node *dnode,
+						  union nb_resource *resource)
+{
+	/* It's all done by redistribute_apply_finish */
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/redistribute/ipv6
+ */
+int isis_instance_redistribute_ipv6_create(enum nb_event event,
+					   const struct lyd_node *dnode,
+					   union nb_resource *resource)
+{
+	/* It's all done by redistribute_apply_finish */
+	return NB_OK;
+}
+
+int isis_instance_redistribute_ipv6_destroy(enum nb_event event,
+					    const struct lyd_node *dnode)
+{
+	struct isis_area *area;
+	int level, type;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_get_entry(dnode, NULL, true);
+	level = yang_dnode_get_enum(dnode, "./level");
+	type = yang_dnode_get_enum(dnode, "./protocol");
+	isis_redist_unset(area, level, AF_INET6, type);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/redistribute/ipv6/route-map
+ */
+int isis_instance_redistribute_ipv6_route_map_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	/* It's all done by redistribute_apply_finish */
+	return NB_OK;
+}
+
+int isis_instance_redistribute_ipv6_route_map_destroy(
+	enum nb_event event, const struct lyd_node *dnode)
+{
+	/* It's all done by redistribute_apply_finish */
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/redistribute/ipv6/metric
+ */
+int isis_instance_redistribute_ipv6_metric_modify(enum nb_event event,
+						  const struct lyd_node *dnode,
+						  union nb_resource *resource)
+{
+	/* It's all done by redistribute_apply_finish */
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/multi-topology/ipv4-multicast
+ */
+static int isis_multi_topology_common(enum nb_event event,
+				      const struct lyd_node *dnode,
+				      const char *topology, bool create)
+{
+	struct isis_area *area;
+	struct isis_area_mt_setting *setting;
+	uint16_t mtid = isis_str2mtid(topology);
+
+	switch (event) {
+	case NB_EV_VALIDATE:
+		if (mtid == (uint16_t)-1) {
+			flog_warn(EC_LIB_NB_CB_CONFIG_VALIDATE,
+				  "Unknown topology %s", topology);
+			return NB_ERR_VALIDATION;
+		}
+		break;
+	case NB_EV_PREPARE:
+	case NB_EV_ABORT:
+		break;
+	case NB_EV_APPLY:
+		area = nb_running_get_entry(dnode, NULL, true);
+		setting = area_get_mt_setting(area, mtid);
+		setting->enabled = create;
+		lsp_regenerate_schedule(area, IS_LEVEL_1 | IS_LEVEL_2, 0);
+		break;
+	}
+
+	return NB_OK;
+}
+
+static int isis_multi_topology_overload_common(enum nb_event event,
+					       const struct lyd_node *dnode,
+					       const char *topology)
+{
+	struct isis_area *area;
+	struct isis_area_mt_setting *setting;
+	uint16_t mtid = isis_str2mtid(topology);
+
+	/* validation is done in isis_multi_topology_common */
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_get_entry(dnode, NULL, true);
+	setting = area_get_mt_setting(area, mtid);
+	setting->overload = yang_dnode_get_bool(dnode, NULL);
+	if (setting->enabled)
+		lsp_regenerate_schedule(area, IS_LEVEL_1 | IS_LEVEL_2, 0);
+
+	return NB_OK;
+}
+
+int isis_instance_multi_topology_ipv4_multicast_create(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	return isis_multi_topology_common(event, dnode, "ipv4-multicast", true);
+}
+
+int isis_instance_multi_topology_ipv4_multicast_destroy(
+	enum nb_event event, const struct lyd_node *dnode)
+{
+	return isis_multi_topology_common(event, dnode, "ipv4-multicast",
+					  false);
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/multi-topology/ipv4-multicast/overload
+ */
+int isis_instance_multi_topology_ipv4_multicast_overload_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	return isis_multi_topology_overload_common(event, dnode,
+						   "ipv4-multicast");
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/multi-topology/ipv4-management
+ */
+int isis_instance_multi_topology_ipv4_management_create(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	return isis_multi_topology_common(event, dnode, "ipv4-mgmt", true);
+}
+
+int isis_instance_multi_topology_ipv4_management_destroy(
+	enum nb_event event, const struct lyd_node *dnode)
+{
+	return isis_multi_topology_common(event, dnode, "ipv4-mgmt", false);
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/multi-topology/ipv4-management/overload
+ */
+int isis_instance_multi_topology_ipv4_management_overload_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	return isis_multi_topology_overload_common(event, dnode, "ipv4-mgmt");
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/multi-topology/ipv6-unicast
+ */
+int isis_instance_multi_topology_ipv6_unicast_create(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	return isis_multi_topology_common(event, dnode, "ipv6-unicast", true);
+}
+
+int isis_instance_multi_topology_ipv6_unicast_destroy(
+	enum nb_event event, const struct lyd_node *dnode)
+{
+	return isis_multi_topology_common(event, dnode, "ipv6-unicast", false);
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/multi-topology/ipv6-unicast/overload
+ */
+int isis_instance_multi_topology_ipv6_unicast_overload_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	return isis_multi_topology_overload_common(event, dnode,
+						   "ipv6-unicast");
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/multi-topology/ipv6-multicast
+ */
+int isis_instance_multi_topology_ipv6_multicast_create(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	return isis_multi_topology_common(event, dnode, "ipv6-multicast", true);
+}
+
+int isis_instance_multi_topology_ipv6_multicast_destroy(
+	enum nb_event event, const struct lyd_node *dnode)
+{
+	return isis_multi_topology_common(event, dnode, "ipv6-multicast",
+					  false);
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/multi-topology/ipv6-multicast/overload
+ */
+int isis_instance_multi_topology_ipv6_multicast_overload_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	return isis_multi_topology_overload_common(event, dnode,
+						   "ipv6-multicast");
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/multi-topology/ipv6-management
+ */
+int isis_instance_multi_topology_ipv6_management_create(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	return isis_multi_topology_common(event, dnode, "ipv6-mgmt", true);
+}
+
+int isis_instance_multi_topology_ipv6_management_destroy(
+	enum nb_event event, const struct lyd_node *dnode)
+{
+	return isis_multi_topology_common(event, dnode, "ipv6-mgmt", false);
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/multi-topology/ipv6-management/overload
+ */
+int isis_instance_multi_topology_ipv6_management_overload_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	return isis_multi_topology_overload_common(event, dnode, "ipv6-mgmt");
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/multi-topology/ipv6-dstsrc
+ */
+int isis_instance_multi_topology_ipv6_dstsrc_create(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	return isis_multi_topology_common(event, dnode, "ipv6-dstsrc", true);
+}
+
+int isis_instance_multi_topology_ipv6_dstsrc_destroy(
+	enum nb_event event, const struct lyd_node *dnode)
+{
+	return isis_multi_topology_common(event, dnode, "ipv6-dstsrc", false);
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/multi-topology/ipv6-dstsrc/overload
+ */
+int isis_instance_multi_topology_ipv6_dstsrc_overload_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	return isis_multi_topology_overload_common(event, dnode, "ipv6-dstsrc");
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/log-adjacency-changes
+ */
+int isis_instance_log_adjacency_changes_modify(enum nb_event event,
+					       const struct lyd_node *dnode,
+					       union nb_resource *resource)
+{
+	struct isis_area *area;
+	bool log = yang_dnode_get_bool(dnode, NULL);
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_get_entry(dnode, NULL, true);
+	area->log_adj_changes = log ? 1 : 0;
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/mpls-te
+ */
+int isis_instance_mpls_te_create(enum nb_event event,
+				 const struct lyd_node *dnode,
+				 union nb_resource *resource)
+{
+	struct listnode *node;
+	struct isis_area *area;
+	struct isis_circuit *circuit;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_get_entry(dnode, NULL, true);
+	if (area->mta == NULL) {
+
+		struct mpls_te_area *new;
+
+		zlog_debug("ISIS-TE(%s): Initialize MPLS Traffic Engineering",
+			   area->area_tag);
+
+		new = XCALLOC(MTYPE_ISIS_MPLS_TE, sizeof(struct mpls_te_area));
+
+		/* Initialize MPLS_TE structure */
+		new->status = enable;
+		new->level = 0;
+		new->inter_as = off;
+		new->interas_areaid.s_addr = 0;
+		new->router_id.s_addr = 0;
+
+		area->mta = new;
+	} else {
+		area->mta->status = enable;
+	}
+
+	/* Update Extended TLVs according to Interface link parameters */
+	for (ALL_LIST_ELEMENTS_RO(area->circuit_list, node, circuit))
+		isis_link_params_update(circuit, circuit->interface);
+
+	/* Reoriginate STD_TE & GMPLS circuits */
+	lsp_regenerate_schedule(area, area->is_type, 0);
+
+	return NB_OK;
+}
+
+int isis_instance_mpls_te_destroy(enum nb_event event,
+				  const struct lyd_node *dnode)
+{
+	struct listnode *node;
+	struct isis_area *area;
+	struct isis_circuit *circuit;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_get_entry(dnode, NULL, true);
+	if (IS_MPLS_TE(area->mta))
+		area->mta->status = disable;
+	else
+		return NB_OK;
+
+	/* Flush LSP if circuit engage */
+	for (ALL_LIST_ELEMENTS_RO(area->circuit_list, node, circuit)) {
+		if (!IS_EXT_TE(circuit->ext))
+			continue;
+
+		/* disable MPLS_TE Circuit keeping SR one's */
+		if (IS_SUBTLV(circuit->ext, EXT_ADJ_SID))
+			circuit->ext->status = EXT_ADJ_SID;
+		else if (IS_SUBTLV(circuit->ext, EXT_LAN_ADJ_SID))
+			circuit->ext->status = EXT_LAN_ADJ_SID;
+		else
+			circuit->ext->status = 0;
+	}
+
+	/* Reoriginate STD_TE & GMPLS circuits */
+	lsp_regenerate_schedule(area, area->is_type, 0);
+
+	zlog_debug("ISIS-TE(%s): Disabled MPLS Traffic Engineering",
+		   area->area_tag);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/mpls-te/router-address
+ */
+int isis_instance_mpls_te_router_address_modify(enum nb_event event,
+						const struct lyd_node *dnode,
+						union nb_resource *resource)
+{
+	struct in_addr value;
+	struct isis_area *area;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_get_entry(dnode, NULL, true);
+	/* only proceed if MPLS-TE is enabled */
+	if (!IS_MPLS_TE(area->mta))
+		return NB_OK;
+
+	/* Update Area Router ID */
+	yang_dnode_get_ipv4(&value, dnode, NULL);
+	area->mta->router_id.s_addr = value.s_addr;
+
+	/* And re-schedule LSP update */
+	lsp_regenerate_schedule(area, area->is_type, 0);
+
+	return NB_OK;
+}
+
+int isis_instance_mpls_te_router_address_destroy(enum nb_event event,
+						 const struct lyd_node *dnode)
+{
+	struct isis_area *area;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_get_entry(dnode, NULL, true);
+	/* only proceed if MPLS-TE is enabled */
+	if (!IS_MPLS_TE(area->mta))
+		return NB_OK;
+
+	/* Reset Area Router ID */
+	area->mta->router_id.s_addr = INADDR_ANY;
+
+	/* And re-schedule LSP update */
+	lsp_regenerate_schedule(area, area->is_type, 0);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-interface:lib/interface/frr-isisd:isis
+ */
+int lib_interface_isis_create(enum nb_event event, const struct lyd_node *dnode,
+			      union nb_resource *resource)
+{
+	struct isis_area *area;
+	struct interface *ifp;
+	struct isis_circuit *circuit;
+	const char *area_tag = yang_dnode_get_string(dnode, "./area-tag");
+	uint32_t min_mtu, actual_mtu;
+
+	switch (event) {
+	case NB_EV_PREPARE:
+	case NB_EV_ABORT:
+		break;
+	case NB_EV_VALIDATE:
+		/* check if interface mtu is sufficient. If the area has not
+		 * been created yet, assume default MTU for the area
+		 */
+		ifp = nb_running_get_entry(dnode, NULL, false);
+		/* zebra might not know yet about the MTU - nothing we can do */
+		if (!ifp || ifp->mtu == 0)
+			break;
+		actual_mtu =
+			if_is_broadcast(ifp) ? ifp->mtu - LLC_LEN : ifp->mtu;
+		area = isis_area_lookup(area_tag);
+		if (area)
+			min_mtu = area->lsp_mtu;
+		else
+#ifndef FABRICD
+			min_mtu = yang_get_default_uint16(
+				"/frr-isisd:isis/instance/lsp/mtu");
+#else
+			min_mtu = DEFAULT_LSP_MTU;
+#endif /* ifndef FABRICD */
+		if (actual_mtu < min_mtu) {
+			flog_warn(EC_LIB_NB_CB_CONFIG_VALIDATE,
+				  "Interface %s has MTU %" PRIu32
+				  ", minimum MTU for the area is %" PRIu32 "",
+				  ifp->name, actual_mtu, min_mtu);
+			return NB_ERR_VALIDATION;
+		}
+		break;
+	case NB_EV_APPLY:
+		area = isis_area_lookup(area_tag);
+		/* The area should have already be created. We are
+		 * setting the priority of the global isis area creation
+		 * slightly lower, so it should be executed first, but I
+		 * cannot rely on that so here I have to check.
+		 */
+		if (!area) {
+			flog_err(
+				EC_LIB_NB_CB_CONFIG_APPLY,
+				"%s: attempt to create circuit for area %s before the area has been created",
+				__func__, area_tag);
+			abort();
+		}
+
+		ifp = nb_running_get_entry(dnode, NULL, true);
+		circuit = isis_circuit_create(area, ifp);
+		assert(circuit
+		       && (circuit->state == C_STATE_CONF
+			   || circuit->state == C_STATE_UP));
+		nb_running_set_entry(dnode, circuit);
+		break;
+	}
+
+	return NB_OK;
+}
+
+int lib_interface_isis_destroy(enum nb_event event,
+			       const struct lyd_node *dnode)
+{
+	struct isis_circuit *circuit;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	circuit = nb_running_unset_entry(dnode);
+	if (!circuit)
+		return NB_ERR_INCONSISTENCY;
+	if (circuit->state == C_STATE_UP || circuit->state == C_STATE_CONF)
+		isis_csm_state_change(ISIS_DISABLE, circuit, circuit->area);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-interface:lib/interface/frr-isisd:isis/area-tag
+ */
+int lib_interface_isis_area_tag_modify(enum nb_event event,
+				       const struct lyd_node *dnode,
+				       union nb_resource *resource)
+{
+	struct isis_circuit *circuit;
+	struct interface *ifp;
+	struct vrf *vrf;
+	const char *area_tag, *ifname, *vrfname;
+
+	if (event == NB_EV_VALIDATE) {
+		/* libyang doesn't like relative paths across module boundaries
+		 */
+		ifname = yang_dnode_get_string(dnode->parent->parent, "./name");
+		vrfname = yang_dnode_get_string(dnode->parent->parent, "./vrf");
+		vrf = vrf_lookup_by_name(vrfname);
+		assert(vrf);
+		ifp = if_lookup_by_name(ifname, vrf->vrf_id);
+		if (!ifp)
+			return NB_OK;
+		circuit = circuit_lookup_by_ifp(ifp, isis->init_circ_list);
+		area_tag = yang_dnode_get_string(dnode, NULL);
+		if (circuit && circuit->area && circuit->area->area_tag
+		    && strcmp(circuit->area->area_tag, area_tag)) {
+			flog_warn(EC_LIB_NB_CB_CONFIG_VALIDATE,
+				  "ISIS circuit is already defined on %s",
+				  circuit->area->area_tag);
+			return NB_ERR_VALIDATION;
+		}
+	}
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-interface:lib/interface/frr-isisd:isis/circuit-type
+ */
+int lib_interface_isis_circuit_type_modify(enum nb_event event,
+					   const struct lyd_node *dnode,
+					   union nb_resource *resource)
+{
+	int circ_type = yang_dnode_get_enum(dnode, NULL);
+	struct isis_circuit *circuit;
+	struct interface *ifp;
+	struct vrf *vrf;
+	const char *ifname, *vrfname;
+
+	switch (event) {
+	case NB_EV_VALIDATE:
+		/* libyang doesn't like relative paths across module boundaries
+		 */
+		ifname = yang_dnode_get_string(dnode->parent->parent, "./name");
+		vrfname = yang_dnode_get_string(dnode->parent->parent, "./vrf");
+		vrf = vrf_lookup_by_name(vrfname);
+		assert(vrf);
+		ifp = if_lookup_by_name(ifname, vrf->vrf_id);
+		if (!ifp)
+			break;
+		circuit = circuit_lookup_by_ifp(ifp, isis->init_circ_list);
+		if (circuit && circuit->state == C_STATE_UP
+		    && circuit->area->is_type != IS_LEVEL_1_AND_2
+		    && circuit->area->is_type != circ_type) {
+			flog_warn(EC_LIB_NB_CB_CONFIG_VALIDATE,
+				  "Invalid circuit level for area %s",
+				  circuit->area->area_tag);
+			return NB_ERR_VALIDATION;
+		}
+		break;
+	case NB_EV_PREPARE:
+	case NB_EV_ABORT:
+		break;
+	case NB_EV_APPLY:
+		circuit = nb_running_get_entry(dnode, NULL, true);
+		isis_circuit_is_type_set(circuit, circ_type);
+		break;
+	}
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-interface:lib/interface/frr-isisd:isis/ipv4-routing
+ */
+int lib_interface_isis_ipv4_routing_modify(enum nb_event event,
+					   const struct lyd_node *dnode,
+					   union nb_resource *resource)
+{
+	bool ipv4, ipv6;
+	struct isis_circuit *circuit;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	circuit = nb_running_get_entry(dnode, NULL, true);
+	ipv4 = yang_dnode_get_bool(dnode, NULL);
+	ipv6 = yang_dnode_get_bool(dnode, "../ipv6-routing");
+	isis_circuit_af_set(circuit, ipv4, ipv6);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-interface:lib/interface/frr-isisd:isis/ipv6-routing
+ */
+int lib_interface_isis_ipv6_routing_modify(enum nb_event event,
+					   const struct lyd_node *dnode,
+					   union nb_resource *resource)
+{
+	bool ipv4, ipv6;
+	struct isis_circuit *circuit;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	circuit = nb_running_get_entry(dnode, NULL, true);
+	ipv4 = yang_dnode_exists(dnode, "../ipv4-routing");
+	ipv6 = yang_dnode_get_bool(dnode, NULL);
+	isis_circuit_af_set(circuit, ipv4, ipv6);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-interface:lib/interface/frr-isisd:isis/bfd-monitoring
+ */
+int lib_interface_isis_bfd_monitoring_modify(enum nb_event event,
+					     const struct lyd_node *dnode,
+					     union nb_resource *resource)
+{
+	struct isis_circuit *circuit;
+	bool bfd_monitoring;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	circuit = nb_running_get_entry(dnode, NULL, true);
+	bfd_monitoring = yang_dnode_get_bool(dnode, NULL);
+
+	if (bfd_monitoring) {
+		isis_bfd_circuit_param_set(circuit, BFD_DEF_MIN_RX,
+					   BFD_DEF_MIN_TX, BFD_DEF_DETECT_MULT,
+					   true);
+	} else {
+		isis_bfd_circuit_cmd(circuit, ZEBRA_BFD_DEST_DEREGISTER);
+		bfd_info_free(&circuit->bfd_info);
+	}
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-interface:lib/interface/frr-isisd:isis/csnp-interval/level-1
+ */
+int lib_interface_isis_csnp_interval_level_1_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	struct isis_circuit *circuit;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	circuit = nb_running_get_entry(dnode, NULL, true);
+	circuit->csnp_interval[0] = yang_dnode_get_uint16(dnode, NULL);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-interface:lib/interface/frr-isisd:isis/csnp-interval/level-2
+ */
+int lib_interface_isis_csnp_interval_level_2_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	struct isis_circuit *circuit;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	circuit = nb_running_get_entry(dnode, NULL, true);
+	circuit->csnp_interval[1] = yang_dnode_get_uint16(dnode, NULL);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-interface:lib/interface/frr-isisd:isis/psnp-interval/level-1
+ */
+int lib_interface_isis_psnp_interval_level_1_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	struct isis_circuit *circuit;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	circuit = nb_running_get_entry(dnode, NULL, true);
+	circuit->psnp_interval[0] = yang_dnode_get_uint16(dnode, NULL);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-interface:lib/interface/frr-isisd:isis/psnp-interval/level-2
+ */
+int lib_interface_isis_psnp_interval_level_2_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	struct isis_circuit *circuit;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	circuit = nb_running_get_entry(dnode, NULL, true);
+	circuit->psnp_interval[1] = yang_dnode_get_uint16(dnode, NULL);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-interface:lib/interface/frr-isisd:isis/hello/padding
+ */
+int lib_interface_isis_hello_padding_modify(enum nb_event event,
+					    const struct lyd_node *dnode,
+					    union nb_resource *resource)
+{
+	struct isis_circuit *circuit;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	circuit = nb_running_get_entry(dnode, NULL, true);
+	circuit->pad_hellos = yang_dnode_get_bool(dnode, NULL);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-interface:lib/interface/frr-isisd:isis/hello/interval/level-1
+ */
+int lib_interface_isis_hello_interval_level_1_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	struct isis_circuit *circuit;
+	uint32_t interval;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	circuit = nb_running_get_entry(dnode, NULL, true);
+	interval = yang_dnode_get_uint32(dnode, NULL);
+	circuit->hello_interval[0] = interval;
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-interface:lib/interface/frr-isisd:isis/hello/interval/level-2
+ */
+int lib_interface_isis_hello_interval_level_2_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	struct isis_circuit *circuit;
+	uint32_t interval;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	circuit = nb_running_get_entry(dnode, NULL, true);
+	interval = yang_dnode_get_uint32(dnode, NULL);
+	circuit->hello_interval[1] = interval;
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-interface:lib/interface/frr-isisd:isis/hello/multiplier/level-1
+ */
+int lib_interface_isis_hello_multiplier_level_1_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	struct isis_circuit *circuit;
+	uint16_t multi;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	circuit = nb_running_get_entry(dnode, NULL, true);
+	multi = yang_dnode_get_uint16(dnode, NULL);
+	circuit->hello_multiplier[0] = multi;
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-interface:lib/interface/frr-isisd:isis/hello/multiplier/level-2
+ */
+int lib_interface_isis_hello_multiplier_level_2_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	struct isis_circuit *circuit;
+	uint16_t multi;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	circuit = nb_running_get_entry(dnode, NULL, true);
+	multi = yang_dnode_get_uint16(dnode, NULL);
+	circuit->hello_multiplier[1] = multi;
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-interface:lib/interface/frr-isisd:isis/metric/level-1
+ */
+int lib_interface_isis_metric_level_1_modify(enum nb_event event,
+					     const struct lyd_node *dnode,
+					     union nb_resource *resource)
+{
+	struct isis_circuit *circuit;
+	unsigned int met;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	circuit = nb_running_get_entry(dnode, NULL, true);
+	met = yang_dnode_get_uint32(dnode, NULL);
+	isis_circuit_metric_set(circuit, IS_LEVEL_1, met);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-interface:lib/interface/frr-isisd:isis/metric/level-2
+ */
+int lib_interface_isis_metric_level_2_modify(enum nb_event event,
+					     const struct lyd_node *dnode,
+					     union nb_resource *resource)
+{
+	struct isis_circuit *circuit;
+	unsigned int met;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	circuit = nb_running_get_entry(dnode, NULL, true);
+	met = yang_dnode_get_uint32(dnode, NULL);
+	isis_circuit_metric_set(circuit, IS_LEVEL_2, met);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-interface:lib/interface/frr-isisd:isis/priority/level-1
+ */
+int lib_interface_isis_priority_level_1_modify(enum nb_event event,
+					       const struct lyd_node *dnode,
+					       union nb_resource *resource)
+{
+	struct isis_circuit *circuit;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	circuit = nb_running_get_entry(dnode, NULL, true);
+	circuit->priority[0] = yang_dnode_get_uint8(dnode, NULL);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-interface:lib/interface/frr-isisd:isis/priority/level-2
+ */
+int lib_interface_isis_priority_level_2_modify(enum nb_event event,
+					       const struct lyd_node *dnode,
+					       union nb_resource *resource)
+{
+	struct isis_circuit *circuit;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	circuit = nb_running_get_entry(dnode, NULL, true);
+	circuit->priority[1] = yang_dnode_get_uint8(dnode, NULL);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-interface:lib/interface/frr-isisd:isis/network-type
+ */
+int lib_interface_isis_network_type_modify(enum nb_event event,
+					   const struct lyd_node *dnode,
+					   union nb_resource *resource)
+{
+	struct isis_circuit *circuit;
+	int net_type = yang_dnode_get_enum(dnode, NULL);
+
+	switch (event) {
+	case NB_EV_VALIDATE:
+		circuit = nb_running_get_entry(dnode, NULL, false);
+		if (!circuit)
+			break;
+		if (circuit->circ_type == CIRCUIT_T_LOOPBACK) {
+			flog_warn(
+				EC_LIB_NB_CB_CONFIG_VALIDATE,
+				"Cannot change network type on loopback interface");
+			return NB_ERR_VALIDATION;
+		}
+		if (net_type == CIRCUIT_T_BROADCAST
+		    && circuit->state == C_STATE_UP
+		    && !if_is_broadcast(circuit->interface)) {
+			flog_warn(
+				EC_LIB_NB_CB_CONFIG_VALIDATE,
+				"Cannot configure non-broadcast interface for broadcast operation");
+			return NB_ERR_VALIDATION;
+		}
+		break;
+	case NB_EV_PREPARE:
+	case NB_EV_ABORT:
+		break;
+	case NB_EV_APPLY:
+		circuit = nb_running_get_entry(dnode, NULL, true);
+		isis_circuit_circ_type_set(circuit, net_type);
+		break;
+	}
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-interface:lib/interface/frr-isisd:isis/passive
+ */
+int lib_interface_isis_passive_modify(enum nb_event event,
+				      const struct lyd_node *dnode,
+				      union nb_resource *resource)
+{
+	struct isis_circuit *circuit;
+	struct isis_area *area;
+	struct interface *ifp;
+	bool passive = yang_dnode_get_bool(dnode, NULL);
+
+	/* validation only applies if we are setting passive to false */
+	if (!passive && event == NB_EV_VALIDATE) {
+		circuit = nb_running_get_entry(dnode, NULL, false);
+		if (!circuit)
+			return NB_OK;
+		ifp = circuit->interface;
+		if (!ifp)
+			return NB_OK;
+		if (if_is_loopback(ifp)) {
+			flog_warn(EC_LIB_NB_CB_CONFIG_VALIDATE,
+				  "Loopback is always passive");
+			return NB_ERR_VALIDATION;
+		}
+	}
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	circuit = nb_running_get_entry(dnode, NULL, true);
+	if (circuit->state != C_STATE_UP) {
+		circuit->is_passive = passive;
+	} else {
+		area = circuit->area;
+		isis_csm_state_change(ISIS_DISABLE, circuit, area);
+		circuit->is_passive = passive;
+		isis_csm_state_change(ISIS_ENABLE, circuit, area);
+	}
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-interface:lib/interface/frr-isisd:isis/password
+ */
+int lib_interface_isis_password_create(enum nb_event event,
+				       const struct lyd_node *dnode,
+				       union nb_resource *resource)
+{
+	return NB_OK;
+}
+
+int lib_interface_isis_password_destroy(enum nb_event event,
+					const struct lyd_node *dnode)
+{
+	struct isis_circuit *circuit;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	circuit = nb_running_get_entry(dnode, NULL, true);
+	isis_circuit_passwd_unset(circuit);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-interface:lib/interface/frr-isisd:isis/password/password
+ */
+int lib_interface_isis_password_password_modify(enum nb_event event,
+						const struct lyd_node *dnode,
+						union nb_resource *resource)
+{
+	struct isis_circuit *circuit;
+	const char *password;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	password = yang_dnode_get_string(dnode, NULL);
+	circuit = nb_running_get_entry(dnode, NULL, true);
+
+	isis_circuit_passwd_set(circuit, circuit->passwd.type, password);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-interface:lib/interface/frr-isisd:isis/password/password-type
+ */
+int lib_interface_isis_password_password_type_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	struct isis_circuit *circuit;
+	uint8_t pass_type;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	pass_type = yang_dnode_get_enum(dnode, NULL);
+	circuit = nb_running_get_entry(dnode, NULL, true);
+	circuit->passwd.type = pass_type;
+
+	return NB_OK;
+}
+
+/*
+ * XPath:
+ * /frr-interface:lib/interface/frr-isisd:isis/disable-three-way-handshake
+ */
+int lib_interface_isis_disable_three_way_handshake_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	struct isis_circuit *circuit;
+
+	if (event != NB_EV_APPLY)
+		return NB_OK;
+
+	circuit = nb_running_get_entry(dnode, NULL, true);
+	circuit->disable_threeway_adj = yang_dnode_get_bool(dnode, NULL);
+
+	return NB_OK;
+}
+
+/*
+ * XPath:
+ * /frr-interface:lib/interface/frr-isisd:isis/multi-topology/ipv4-unicast
+ */
+static int lib_interface_isis_multi_topology_common(
+	enum nb_event event, const struct lyd_node *dnode, uint16_t mtid)
+{
+	struct isis_circuit *circuit;
+	bool value;
+
+	switch (event) {
+	case NB_EV_VALIDATE:
+		circuit = nb_running_get_entry(dnode, NULL, false);
+		if (circuit && circuit->area && circuit->area->oldmetric) {
+			flog_warn(
+				EC_LIB_NB_CB_CONFIG_VALIDATE,
+				"Multi topology IS-IS can only be used with wide metrics");
+			return NB_ERR_VALIDATION;
+		}
+		break;
+	case NB_EV_PREPARE:
+	case NB_EV_ABORT:
+		break;
+	case NB_EV_APPLY:
+		circuit = nb_running_get_entry(dnode, NULL, true);
+		value = yang_dnode_get_bool(dnode, NULL);
+		isis_circuit_mt_enabled_set(circuit, mtid, value);
+		break;
+	}
+
+	return NB_OK;
+}
+
+int lib_interface_isis_multi_topology_ipv4_unicast_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	return lib_interface_isis_multi_topology_common(event, dnode,
+							ISIS_MT_IPV4_UNICAST);
+}
+
+/*
+ * XPath:
+ * /frr-interface:lib/interface/frr-isisd:isis/multi-topology/ipv4-multicast
+ */
+int lib_interface_isis_multi_topology_ipv4_multicast_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	return lib_interface_isis_multi_topology_common(event, dnode,
+							ISIS_MT_IPV4_MULTICAST);
+}
+
+/*
+ * XPath:
+ * /frr-interface:lib/interface/frr-isisd:isis/multi-topology/ipv4-management
+ */
+int lib_interface_isis_multi_topology_ipv4_management_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	return lib_interface_isis_multi_topology_common(event, dnode,
+							ISIS_MT_IPV4_MGMT);
+}
+
+/*
+ * XPath:
+ * /frr-interface:lib/interface/frr-isisd:isis/multi-topology/ipv6-unicast
+ */
+int lib_interface_isis_multi_topology_ipv6_unicast_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	return lib_interface_isis_multi_topology_common(event, dnode,
+							ISIS_MT_IPV6_UNICAST);
+}
+
+/*
+ * XPath:
+ * /frr-interface:lib/interface/frr-isisd:isis/multi-topology/ipv6-multicast
+ */
+int lib_interface_isis_multi_topology_ipv6_multicast_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	return lib_interface_isis_multi_topology_common(event, dnode,
+							ISIS_MT_IPV6_MULTICAST);
+}
+
+/*
+ * XPath:
+ * /frr-interface:lib/interface/frr-isisd:isis/multi-topology/ipv6-management
+ */
+int lib_interface_isis_multi_topology_ipv6_management_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	return lib_interface_isis_multi_topology_common(event, dnode,
+							ISIS_MT_IPV6_MGMT);
+}
+
+/*
+ * XPath: /frr-interface:lib/interface/frr-isisd:isis/multi-topology/ipv6-dstsrc
+ */
+int lib_interface_isis_multi_topology_ipv6_dstsrc_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource)
+{
+	return lib_interface_isis_multi_topology_common(event, dnode,
+							ISIS_MT_IPV6_DSTSRC);
+}
diff --git a/isisd/isis_nb_notifications.c b/isisd/isis_nb_notifications.c
new file mode 100644
index 000000000..ea33ec10e
--- /dev/null
+++ b/isisd/isis_nb_notifications.c
@@ -0,0 +1,491 @@
+/*
+ * Copyright (C) 2018        Volta Networks
+ *                           Emanuele Di Pascale
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; see the file COPYING; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <zebra.h>
+
+#include "northbound.h"
+#include "log.h"
+
+#include "isisd/isisd.h"
+#include "isisd/isis_nb.h"
+#include "isisd/isis_adjacency.h"
+#include "isisd/isis_dynhn.h"
+#include "isisd/isis_misc.h"
+
+/*
+ * Helper functions.
+ */
+static void notif_prep_instance_hdr(const char *xpath,
+				    const struct isis_area *area,
+				    const char *routing_instance,
+				    struct list *args)
+{
+	char xpath_arg[XPATH_MAXLEN];
+	struct yang_data *data;
+
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/routing-instance", xpath);
+	data = yang_data_new_string(xpath_arg, routing_instance);
+	listnode_add(args, data);
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/routing-protocol-name",
+		 xpath);
+	data = yang_data_new_string(xpath_arg, area->area_tag);
+	listnode_add(args, data);
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/isis-level", xpath);
+	data = yang_data_new_enum(xpath_arg, area->is_type);
+	listnode_add(args, data);
+}
+
+static void notif_prepr_iface_hdr(const char *xpath,
+				  const struct isis_circuit *circuit,
+				  struct list *args)
+{
+	char xpath_arg[XPATH_MAXLEN];
+	struct yang_data *data;
+
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/interface-name", xpath);
+	data = yang_data_new_string(xpath_arg, circuit->interface->name);
+	listnode_add(args, data);
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/interface-level", xpath);
+	data = yang_data_new_enum(xpath_arg, circuit->is_type);
+	listnode_add(args, data);
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/extended-circuit-id", xpath);
+	/* we do not seem to have the extended version of the circuit_id */
+	data = yang_data_new_uint32(xpath_arg, (uint32_t)circuit->circuit_id);
+	listnode_add(args, data);
+}
+
+/*
+ * XPath: /frr-isisd:database-overload
+ */
+void isis_notif_db_overload(const struct isis_area *area, bool overload)
+{
+	const char *xpath = "/frr-isisd:database-overload";
+	struct list *arguments = yang_data_list_new();
+	char xpath_arg[XPATH_MAXLEN];
+	struct yang_data *data;
+
+	notif_prep_instance_hdr(xpath, area, "default", arguments);
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/overload", xpath);
+	data = yang_data_new_enum(xpath_arg, !!overload);
+	listnode_add(arguments, data);
+
+	nb_notification_send(xpath, arguments);
+}
+
+/*
+ * XPath: /frr-isisd:lsp-too-large
+ */
+void isis_notif_lsp_too_large(const struct isis_circuit *circuit,
+			      uint32_t pdu_size, const char *lsp_id)
+{
+	const char *xpath = "/frr-isisd:lsp-too-large";
+	struct list *arguments = yang_data_list_new();
+	char xpath_arg[XPATH_MAXLEN];
+	struct yang_data *data;
+	struct isis_area *area = circuit->area;
+
+	notif_prep_instance_hdr(xpath, area, "default", arguments);
+	notif_prepr_iface_hdr(xpath, circuit, arguments);
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/pdu-size", xpath);
+	data = yang_data_new_uint32(xpath_arg, pdu_size);
+	listnode_add(arguments, data);
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/lsp-id", xpath);
+	data = yang_data_new_string(xpath_arg, lsp_id);
+	listnode_add(arguments, data);
+
+	nb_notification_send(xpath, arguments);
+}
+
+/*
+ * XPath: /frr-isisd:if-state-change
+ */
+void isis_notif_if_state_change(const struct isis_circuit *circuit, bool down)
+{
+	const char *xpath = "/frr-isisd:if-state-change";
+	struct list *arguments = yang_data_list_new();
+	char xpath_arg[XPATH_MAXLEN];
+	struct yang_data *data;
+	struct isis_area *area = circuit->area;
+
+	notif_prep_instance_hdr(xpath, area, "default", arguments);
+	notif_prepr_iface_hdr(xpath, circuit, arguments);
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/state", xpath);
+	data = yang_data_new_enum(xpath_arg, !!down);
+	listnode_add(arguments, data);
+
+	nb_notification_send(xpath, arguments);
+}
+
+/*
+ * XPath: /frr-isisd:corrupted-lsp-detected
+ */
+void isis_notif_corrupted_lsp(const struct isis_area *area, const char *lsp_id)
+{
+	const char *xpath = "/frr-isisd:corrupted-lsp-detected";
+	struct list *arguments = yang_data_list_new();
+	char xpath_arg[XPATH_MAXLEN];
+	struct yang_data *data;
+
+	notif_prep_instance_hdr(xpath, area, "default", arguments);
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/lsp-id", xpath);
+	data = yang_data_new_string(xpath_arg, lsp_id);
+	listnode_add(arguments, data);
+
+	nb_notification_send(xpath, arguments);
+}
+
+/*
+ * XPath: /frr-isisd:attempt-to-exceed-max-sequence
+ */
+void isis_notif_lsp_exceed_max(const struct isis_area *area, const char *lsp_id)
+{
+	const char *xpath = "/frr-isisd:attempt-to-exceed-max-sequence";
+	struct list *arguments = yang_data_list_new();
+	char xpath_arg[XPATH_MAXLEN];
+	struct yang_data *data;
+
+	notif_prep_instance_hdr(xpath, area, "default", arguments);
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/lsp-id", xpath);
+	data = yang_data_new_string(xpath_arg, lsp_id);
+	listnode_add(arguments, data);
+
+	nb_notification_send(xpath, arguments);
+}
+
+/*
+ * XPath: /frr-isisd:max-area-addresses-mismatch
+ */
+void isis_notif_max_area_addr_mismatch(const struct isis_circuit *circuit,
+				       uint8_t max_area_addrs,
+				       const char *raw_pdu)
+{
+	const char *xpath = "/frr-isisd:max-area-addresses-mismatch";
+	struct list *arguments = yang_data_list_new();
+	char xpath_arg[XPATH_MAXLEN];
+	struct yang_data *data;
+	struct isis_area *area = circuit->area;
+
+	notif_prep_instance_hdr(xpath, area, "default", arguments);
+	notif_prepr_iface_hdr(xpath, circuit, arguments);
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/max-area-addresses", xpath);
+	data = yang_data_new_uint8(xpath_arg, max_area_addrs);
+	listnode_add(arguments, data);
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/raw-pdu", xpath);
+	data = yang_data_new(xpath_arg, raw_pdu);
+	listnode_add(arguments, data);
+
+	nb_notification_send(xpath, arguments);
+}
+
+/*
+ * XPath: /frr-isisd:authentication-type-failure
+ */
+void isis_notif_authentication_type_failure(const struct isis_circuit *circuit,
+					    const char *raw_pdu)
+{
+	const char *xpath = "/frr-isisd:authentication-type-failure";
+	struct list *arguments = yang_data_list_new();
+	char xpath_arg[XPATH_MAXLEN];
+	struct yang_data *data;
+	struct isis_area *area = circuit->area;
+
+	notif_prep_instance_hdr(xpath, area, "default", arguments);
+	notif_prepr_iface_hdr(xpath, circuit, arguments);
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/raw-pdu", xpath);
+	data = yang_data_new(xpath_arg, raw_pdu);
+	listnode_add(arguments, data);
+
+	nb_notification_send(xpath, arguments);
+}
+
+/*
+ * XPath: /frr-isisd:authentication-failure
+ */
+void isis_notif_authentication_failure(const struct isis_circuit *circuit,
+				       const char *raw_pdu)
+{
+	const char *xpath = "/frr-isisd:authentication-failure";
+	struct list *arguments = yang_data_list_new();
+	char xpath_arg[XPATH_MAXLEN];
+	struct yang_data *data;
+	struct isis_area *area = circuit->area;
+
+	notif_prep_instance_hdr(xpath, area, "default", arguments);
+	notif_prepr_iface_hdr(xpath, circuit, arguments);
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/raw-pdu", xpath);
+	data = yang_data_new(xpath_arg, raw_pdu);
+	listnode_add(arguments, data);
+
+	nb_notification_send(xpath, arguments);
+}
+
+/*
+ * XPath: /frr-isisd:adjacency-state-change
+ */
+void isis_notif_adj_state_change(const struct isis_adjacency *adj,
+				 int new_state, const char *reason)
+{
+	const char *xpath = "/frr-isisd:adjacency-state-change";
+	struct list *arguments = yang_data_list_new();
+	char xpath_arg[XPATH_MAXLEN];
+	struct yang_data *data;
+	struct isis_circuit *circuit = adj->circuit;
+	struct isis_area *area = circuit->area;
+	struct isis_dynhn *dyn = dynhn_find_by_id(adj->sysid);
+
+	notif_prep_instance_hdr(xpath, area, "default", arguments);
+	notif_prepr_iface_hdr(xpath, circuit, arguments);
+	if (dyn) {
+		snprintf(xpath_arg, sizeof(xpath_arg), "%s/neighbor", xpath);
+		data = yang_data_new_string(xpath_arg, dyn->hostname);
+		listnode_add(arguments, data);
+	}
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/neighbor-system-id", xpath);
+	data = yang_data_new_string(xpath_arg, sysid_print(adj->sysid));
+	listnode_add(arguments, data);
+
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/state", xpath);
+	data = yang_data_new_string(xpath_arg, isis_adj_yang_state(new_state));
+	listnode_add(arguments, data);
+	if (new_state == ISIS_ADJ_DOWN) {
+		snprintf(xpath_arg, sizeof(xpath_arg), "%s/reason", xpath);
+		data = yang_data_new_string(xpath_arg, reason);
+		listnode_add(arguments, data);
+	}
+
+	nb_notification_send(xpath, arguments);
+}
+
+/*
+ * XPath: /frr-isisd:rejected-adjacency
+ */
+void isis_notif_reject_adjacency(const struct isis_circuit *circuit,
+				 const char *reason, const char *raw_pdu)
+{
+	const char *xpath = "/frr-isisd:rejected-adjacency";
+	struct list *arguments = yang_data_list_new();
+	char xpath_arg[XPATH_MAXLEN];
+	struct yang_data *data;
+	struct isis_area *area = circuit->area;
+
+	notif_prep_instance_hdr(xpath, area, "default", arguments);
+	notif_prepr_iface_hdr(xpath, circuit, arguments);
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/reason", xpath);
+	data = yang_data_new_string(xpath_arg, reason);
+	listnode_add(arguments, data);
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/raw-pdu", xpath);
+	data = yang_data_new(xpath_arg, raw_pdu);
+	listnode_add(arguments, data);
+
+	nb_notification_send(xpath, arguments);
+}
+
+/*
+ * XPath: /frr-isisd:area-mismatch
+ */
+void isis_notif_area_mismatch(const struct isis_circuit *circuit,
+			      const char *raw_pdu)
+{
+	const char *xpath = "/frr-isisd:area-mismatch";
+	struct list *arguments = yang_data_list_new();
+	char xpath_arg[XPATH_MAXLEN];
+	struct yang_data *data;
+	struct isis_area *area = circuit->area;
+
+	notif_prep_instance_hdr(xpath, area, "default", arguments);
+	notif_prepr_iface_hdr(xpath, circuit, arguments);
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/raw-pdu", xpath);
+	data = yang_data_new(xpath_arg, raw_pdu);
+	listnode_add(arguments, data);
+
+	nb_notification_send(xpath, arguments);
+}
+
+/*
+ * XPath: /frr-isisd:lsp-received
+ */
+void isis_notif_lsp_received(const struct isis_circuit *circuit,
+			     const char *lsp_id, uint32_t seqno,
+			     uint32_t timestamp, const char *sys_id)
+{
+	const char *xpath = "/frr-isisd:lsp-received";
+	struct list *arguments = yang_data_list_new();
+	char xpath_arg[XPATH_MAXLEN];
+	struct yang_data *data;
+	struct isis_area *area = circuit->area;
+
+	notif_prep_instance_hdr(xpath, area, "default", arguments);
+	notif_prepr_iface_hdr(xpath, circuit, arguments);
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/lsp-id", xpath);
+	data = yang_data_new_string(xpath_arg, lsp_id);
+	listnode_add(arguments, data);
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/sequence", xpath);
+	data = yang_data_new_uint32(xpath_arg, seqno);
+	listnode_add(arguments, data);
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/received-timestamp", xpath);
+	data = yang_data_new_uint32(xpath_arg, timestamp);
+	listnode_add(arguments, data);
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/neighbor-system-id", xpath);
+	data = yang_data_new_string(xpath_arg, sys_id);
+	listnode_add(arguments, data);
+
+	nb_notification_send(xpath, arguments);
+}
+
+/*
+ * XPath: /frr-isisd:lsp-generation
+ */
+void isis_notif_lsp_gen(const struct isis_area *area, const char *lsp_id,
+			uint32_t seqno, uint32_t timestamp)
+{
+	const char *xpath = "/frr-isisd:lsp-generation";
+	struct list *arguments = yang_data_list_new();
+	char xpath_arg[XPATH_MAXLEN];
+	struct yang_data *data;
+
+	notif_prep_instance_hdr(xpath, area, "default", arguments);
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/lsp-id", xpath);
+	data = yang_data_new_string(xpath_arg, lsp_id);
+	listnode_add(arguments, data);
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/sequence", xpath);
+	data = yang_data_new_uint32(xpath_arg, seqno);
+	listnode_add(arguments, data);
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/send-timestamp", xpath);
+	data = yang_data_new_uint32(xpath_arg, timestamp);
+	listnode_add(arguments, data);
+
+	nb_notification_send(xpath, arguments);
+}
+
+/*
+ * XPath: /frr-isisd:id-len-mismatch
+ */
+void isis_notif_id_len_mismatch(const struct isis_circuit *circuit,
+				uint8_t rcv_id_len, const char *raw_pdu)
+{
+	const char *xpath = "/frr-isisd:id-len-mismatch";
+	struct list *arguments = yang_data_list_new();
+	char xpath_arg[XPATH_MAXLEN];
+	struct yang_data *data;
+	struct isis_area *area = circuit->area;
+
+	notif_prep_instance_hdr(xpath, area, "default", arguments);
+	notif_prepr_iface_hdr(xpath, circuit, arguments);
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/pdu-field-len", xpath);
+	data = yang_data_new_uint8(xpath_arg, rcv_id_len);
+	listnode_add(arguments, data);
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/raw-pdu", xpath);
+	data = yang_data_new(xpath_arg, raw_pdu);
+	listnode_add(arguments, data);
+
+	nb_notification_send(xpath, arguments);
+}
+
+/*
+ * XPath: /frr-isisd:version-skew
+ */
+void isis_notif_version_skew(const struct isis_circuit *circuit,
+			     uint8_t version, const char *raw_pdu)
+{
+	const char *xpath = "/frr-isisd:version-skew";
+	struct list *arguments = yang_data_list_new();
+	char xpath_arg[XPATH_MAXLEN];
+	struct yang_data *data;
+	struct isis_area *area = circuit->area;
+
+	notif_prep_instance_hdr(xpath, area, "default", arguments);
+	notif_prepr_iface_hdr(xpath, circuit, arguments);
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/protocol-version", xpath);
+	data = yang_data_new_uint8(xpath_arg, version);
+	listnode_add(arguments, data);
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/raw-pdu", xpath);
+	data = yang_data_new(xpath_arg, raw_pdu);
+	listnode_add(arguments, data);
+
+	nb_notification_send(xpath, arguments);
+}
+
+/*
+ * XPath: /frr-isisd:lsp-error-detected
+ */
+void isis_notif_lsp_error(const struct isis_circuit *circuit,
+			  const char *lsp_id, const char *raw_pdu,
+			  __attribute__((unused)) uint32_t offset,
+			  __attribute__((unused)) uint8_t tlv_type)
+{
+	const char *xpath = "/frr-isisd:lsp-error-detected";
+	struct list *arguments = yang_data_list_new();
+	char xpath_arg[XPATH_MAXLEN];
+	struct yang_data *data;
+	struct isis_area *area = circuit->area;
+
+	notif_prep_instance_hdr(xpath, area, "default", arguments);
+	notif_prepr_iface_hdr(xpath, circuit, arguments);
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/lsp-id", xpath);
+	data = yang_data_new_string(xpath_arg, lsp_id);
+	listnode_add(arguments, data);
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/raw-pdu", xpath);
+	data = yang_data_new(xpath_arg, raw_pdu);
+	listnode_add(arguments, data);
+	/* ignore offset and tlv_type which cannot be set properly */
+
+	nb_notification_send(xpath, arguments);
+}
+
+/*
+ * XPath: /frr-isisd:sequence-number-skipped
+ */
+void isis_notif_seqno_skipped(const struct isis_circuit *circuit,
+			      const char *lsp_id)
+{
+	const char *xpath = "/frr-isisd:sequence-number-skipped";
+	struct list *arguments = yang_data_list_new();
+	char xpath_arg[XPATH_MAXLEN];
+	struct yang_data *data;
+	struct isis_area *area = circuit->area;
+
+	notif_prep_instance_hdr(xpath, area, "default", arguments);
+	notif_prepr_iface_hdr(xpath, circuit, arguments);
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/lsp-id", xpath);
+	data = yang_data_new_string(xpath_arg, lsp_id);
+	listnode_add(arguments, data);
+
+	nb_notification_send(xpath, arguments);
+}
+
+/*
+ * XPath: /frr-isisd:own-lsp-purge
+ */
+void isis_notif_own_lsp_purge(const struct isis_circuit *circuit,
+			      const char *lsp_id)
+{
+	const char *xpath = "/frr-isisd:own-lsp-purge";
+	struct list *arguments = yang_data_list_new();
+	char xpath_arg[XPATH_MAXLEN];
+	struct yang_data *data;
+	struct isis_area *area = circuit->area;
+
+	notif_prep_instance_hdr(xpath, area, "default", arguments);
+	notif_prepr_iface_hdr(xpath, circuit, arguments);
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/lsp-id", xpath);
+	data = yang_data_new_string(xpath_arg, lsp_id);
+	listnode_add(arguments, data);
+
+	nb_notification_send(xpath, arguments);
+}
diff --git a/isisd/isis_nb_state.c b/isisd/isis_nb_state.c
new file mode 100644
index 000000000..e52d0201d
--- /dev/null
+++ b/isisd/isis_nb_state.c
@@ -0,0 +1,386 @@
+/*
+ * Copyright (C) 2018        Volta Networks
+ *                           Emanuele Di Pascale
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; see the file COPYING; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <zebra.h>
+
+#include "northbound.h"
+#include "linklist.h"
+
+#include "isisd/isisd.h"
+#include "isisd/isis_nb.h"
+#include "isisd/isis_circuit.h"
+#include "isisd/isis_adjacency.h"
+#include "isisd/isis_misc.h"
+
+/*
+ * XPath: /frr-interface:lib/interface/frr-isisd:isis/adjacencies/adjacency
+ */
+const void *
+lib_interface_isis_adjacencies_adjacency_get_next(const void *parent_list_entry,
+						  const void *list_entry)
+{
+	struct interface *ifp;
+	struct isis_circuit *circuit;
+	struct isis_adjacency *adj, *adj_next = NULL;
+	struct list *list;
+	struct listnode *node, *node_next;
+
+	/* Get first adjacency. */
+	if (list_entry == NULL) {
+		ifp = (struct interface *)parent_list_entry;
+		if (!ifp)
+			return NULL;
+
+		circuit = circuit_scan_by_ifp(ifp);
+		if (!circuit)
+			return NULL;
+
+		switch (circuit->circ_type) {
+		case CIRCUIT_T_BROADCAST:
+			for (int level = ISIS_LEVEL1; level <= ISIS_LEVELS;
+			     level++) {
+				adj = listnode_head(
+					circuit->u.bc.adjdb[level - 1]);
+				if (adj)
+					break;
+			}
+			break;
+		case CIRCUIT_T_P2P:
+			adj = circuit->u.p2p.neighbor;
+			break;
+		default:
+			adj = NULL;
+			break;
+		}
+
+		return adj;
+	}
+
+	/* Get next adjacency. */
+	adj = (struct isis_adjacency *)list_entry;
+	circuit = adj->circuit;
+	switch (circuit->circ_type) {
+	case CIRCUIT_T_BROADCAST:
+		list = circuit->u.bc.adjdb[adj->level - 1];
+		node = listnode_lookup(list, adj);
+		node_next = listnextnode(node);
+		if (node_next)
+			adj_next = listgetdata(node_next);
+		else if (adj->level == ISIS_LEVEL1) {
+			/*
+			 * Once we finish the L1 adjacencies, move to the L2
+			 * adjacencies list.
+			 */
+			list = circuit->u.bc.adjdb[ISIS_LEVEL2 - 1];
+			adj_next = listnode_head(list);
+		}
+		break;
+	case CIRCUIT_T_P2P:
+		/* P2P circuits have at most one adjacency. */
+	default:
+		break;
+	}
+
+	return adj_next;
+}
+
+/*
+ * XPath:
+ * /frr-interface:lib/interface/frr-isisd:isis/adjacencies/adjacency/neighbor-sys-type
+ */
+struct yang_data *
+lib_interface_isis_adjacencies_adjacency_neighbor_sys_type_get_elem(
+	const char *xpath, const void *list_entry)
+{
+	const struct isis_adjacency *adj = list_entry;
+
+	return yang_data_new_enum(xpath, adj->level);
+}
+
+/*
+ * XPath:
+ * /frr-interface:lib/interface/frr-isisd:isis/adjacencies/adjacency/neighbor-sysid
+ */
+struct yang_data *
+lib_interface_isis_adjacencies_adjacency_neighbor_sysid_get_elem(
+	const char *xpath, const void *list_entry)
+{
+	const struct isis_adjacency *adj = list_entry;
+
+	return yang_data_new_string(xpath, sysid_print(adj->sysid));
+}
+
+/*
+ * XPath:
+ * /frr-interface:lib/interface/frr-isisd:isis/adjacencies/adjacency/neighbor-extended-circuit-id
+ */
+struct yang_data *
+lib_interface_isis_adjacencies_adjacency_neighbor_extended_circuit_id_get_elem(
+	const char *xpath, const void *list_entry)
+{
+	const struct isis_adjacency *adj = list_entry;
+
+	return yang_data_new_uint32(xpath, adj->circuit->circuit_id);
+}
+
+/*
+ * XPath:
+ * /frr-interface:lib/interface/frr-isisd:isis/adjacencies/adjacency/neighbor-snpa
+ */
+struct yang_data *
+lib_interface_isis_adjacencies_adjacency_neighbor_snpa_get_elem(
+	const char *xpath, const void *list_entry)
+{
+	const struct isis_adjacency *adj = list_entry;
+
+	return yang_data_new_string(xpath, snpa_print(adj->snpa));
+}
+
+/*
+ * XPath:
+ * /frr-interface:lib/interface/frr-isisd:isis/adjacencies/adjacency/hold-timer
+ */
+struct yang_data *lib_interface_isis_adjacencies_adjacency_hold_timer_get_elem(
+	const char *xpath, const void *list_entry)
+{
+	const struct isis_adjacency *adj = list_entry;
+
+	return yang_data_new_uint16(xpath, adj->hold_time);
+}
+
+/*
+ * XPath:
+ * /frr-interface:lib/interface/frr-isisd:isis/adjacencies/adjacency/neighbor-priority
+ */
+struct yang_data *
+lib_interface_isis_adjacencies_adjacency_neighbor_priority_get_elem(
+	const char *xpath, const void *list_entry)
+{
+	const struct isis_adjacency *adj = list_entry;
+
+	return yang_data_new_uint8(xpath, adj->prio[adj->level - 1]);
+}
+
+/*
+ * XPath:
+ * /frr-interface:lib/interface/frr-isisd:isis/adjacencies/adjacency/state
+ */
+struct yang_data *
+lib_interface_isis_adjacencies_adjacency_state_get_elem(const char *xpath,
+							const void *list_entry)
+{
+	const struct isis_adjacency *adj = list_entry;
+
+	return yang_data_new_string(xpath, isis_adj_yang_state(adj->adj_state));
+}
+
+/*
+ * XPath:
+ * /frr-interface:lib/interface/frr-isisd:isis/event-counters/adjacency-changes
+ */
+struct yang_data *lib_interface_isis_event_counters_adjacency_changes_get_elem(
+	const char *xpath, const void *list_entry)
+{
+	struct interface *ifp;
+	struct isis_circuit *circuit;
+
+	ifp = (struct interface *)list_entry;
+	if (!ifp)
+		return NULL;
+
+	circuit = circuit_scan_by_ifp(ifp);
+	if (!circuit)
+		return NULL;
+
+	return yang_data_new_uint32(xpath, circuit->adj_state_changes);
+}
+
+/*
+ * XPath:
+ * /frr-interface:lib/interface/frr-isisd:isis/event-counters/adjacency-number
+ */
+struct yang_data *lib_interface_isis_event_counters_adjacency_number_get_elem(
+	const char *xpath, const void *list_entry)
+{
+	struct interface *ifp;
+	struct isis_circuit *circuit;
+	struct isis_adjacency *adj;
+	struct listnode *node;
+	uint32_t total = 0;
+
+	ifp = (struct interface *)list_entry;
+	if (!ifp)
+		return NULL;
+
+	circuit = circuit_scan_by_ifp(ifp);
+	if (!circuit)
+		return NULL;
+
+	/*
+	 * TODO: keep track of the number of adjacencies instead of calculating
+	 * it on demand.
+	 */
+	switch (circuit->circ_type) {
+	case CIRCUIT_T_BROADCAST:
+		for (int level = ISIS_LEVEL1; level <= ISIS_LEVELS; level++) {
+			for (ALL_LIST_ELEMENTS_RO(
+				     circuit->u.bc.adjdb[level - 1], node, adj))
+				total++;
+		}
+		break;
+	case CIRCUIT_T_P2P:
+		adj = circuit->u.p2p.neighbor;
+		if (adj)
+			total = 1;
+		break;
+	default:
+		break;
+	}
+
+	return yang_data_new_uint32(xpath, total);
+}
+
+/*
+ * XPath: /frr-interface:lib/interface/frr-isisd:isis/event-counters/init-fails
+ */
+struct yang_data *
+lib_interface_isis_event_counters_init_fails_get_elem(const char *xpath,
+						      const void *list_entry)
+{
+	struct interface *ifp;
+	struct isis_circuit *circuit;
+
+	ifp = (struct interface *)list_entry;
+	if (!ifp)
+		return NULL;
+
+	circuit = circuit_scan_by_ifp(ifp);
+	if (!circuit)
+		return NULL;
+
+	return yang_data_new_uint32(xpath, circuit->init_failures);
+}
+
+/*
+ * XPath:
+ * /frr-interface:lib/interface/frr-isisd:isis/event-counters/adjacency-rejects
+ */
+struct yang_data *lib_interface_isis_event_counters_adjacency_rejects_get_elem(
+	const char *xpath, const void *list_entry)
+{
+	struct interface *ifp;
+	struct isis_circuit *circuit;
+
+	ifp = (struct interface *)list_entry;
+	if (!ifp)
+		return NULL;
+
+	circuit = circuit_scan_by_ifp(ifp);
+	if (!circuit)
+		return NULL;
+
+	return yang_data_new_uint32(xpath, circuit->rej_adjacencies);
+}
+
+/*
+ * XPath:
+ * /frr-interface:lib/interface/frr-isisd:isis/event-counters/id-len-mismatch
+ */
+struct yang_data *lib_interface_isis_event_counters_id_len_mismatch_get_elem(
+	const char *xpath, const void *list_entry)
+{
+	struct interface *ifp;
+	struct isis_circuit *circuit;
+
+	ifp = (struct interface *)list_entry;
+	if (!ifp)
+		return NULL;
+
+	circuit = circuit_scan_by_ifp(ifp);
+	if (!circuit)
+		return NULL;
+
+	return yang_data_new_uint32(xpath, circuit->id_len_mismatches);
+}
+
+/*
+ * XPath:
+ * /frr-interface:lib/interface/frr-isisd:isis/event-counters/max-area-addresses-mismatch
+ */
+struct yang_data *
+lib_interface_isis_event_counters_max_area_addresses_mismatch_get_elem(
+	const char *xpath, const void *list_entry)
+{
+	struct interface *ifp;
+	struct isis_circuit *circuit;
+
+	ifp = (struct interface *)list_entry;
+	if (!ifp)
+		return NULL;
+
+	circuit = circuit_scan_by_ifp(ifp);
+	if (!circuit)
+		return NULL;
+
+	return yang_data_new_uint32(xpath, circuit->max_area_addr_mismatches);
+}
+
+/*
+ * XPath:
+ * /frr-interface:lib/interface/frr-isisd:isis/event-counters/authentication-type-fails
+ */
+struct yang_data *
+lib_interface_isis_event_counters_authentication_type_fails_get_elem(
+	const char *xpath, const void *list_entry)
+{
+	struct interface *ifp;
+	struct isis_circuit *circuit;
+
+	ifp = (struct interface *)list_entry;
+	if (!ifp)
+		return NULL;
+
+	circuit = circuit_scan_by_ifp(ifp);
+	if (!circuit)
+		return NULL;
+
+	return yang_data_new_uint32(xpath, circuit->auth_type_failures);
+}
+
+/*
+ * XPath:
+ * /frr-interface:lib/interface/frr-isisd:isis/event-counters/authentication-fails
+ */
+struct yang_data *
+lib_interface_isis_event_counters_authentication_fails_get_elem(
+	const char *xpath, const void *list_entry)
+{
+	struct interface *ifp;
+	struct isis_circuit *circuit;
+
+	ifp = (struct interface *)list_entry;
+	if (!ifp)
+		return NULL;
+
+	circuit = circuit_scan_by_ifp(ifp);
+	if (!circuit)
+		return NULL;
+
+	return yang_data_new_uint32(xpath, circuit->auth_failures);
+}
diff --git a/isisd/isis_northbound.c b/isisd/isis_northbound.c
deleted file mode 100644
index 97b7ae4f7..000000000
--- a/isisd/isis_northbound.c
+++ /dev/null
@@ -1,3932 +0,0 @@
-/*
- * Copyright (C) 2001,2002   Sampo Saaristo
- *                           Tampere University of Technology
- *                           Institute of Communications Engineering
- * Copyright (C) 2018        Volta Networks
- *                           Emanuele Di Pascale
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License as published by the Free
- * Software Foundation; either version 2 of the License, or (at your option)
- * any later version.
- *
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
- * more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; see the file COPYING; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-#include <zebra.h>
-#include "northbound.h"
-#include "libfrr.h"
-#include "linklist.h"
-#include "log.h"
-#include "lib/bfd.h"
-#include "isisd/isis_bfd.h"
-#include "isisd/isis_constants.h"
-#include "isisd/isis_common.h"
-#include "isisd/isis_flags.h"
-#include "isisd/isis_circuit.h"
-#include "isisd/isisd.h"
-#include "isisd/isis_lsp.h"
-#include "isisd/isis_pdu.h"
-#include "isisd/isis_dynhn.h"
-#include "isisd/isis_misc.h"
-#include "isisd/isis_csm.h"
-#include "isisd/isis_adjacency.h"
-#include "isisd/isis_spf.h"
-#include "isisd/isis_te.h"
-#include "isisd/isis_memory.h"
-#include "isisd/isis_mt.h"
-#include "isisd/isis_cli.h"
-#include "isisd/isis_redist.h"
-#include "lib/spf_backoff.h"
-#include "lib/lib_errors.h"
-#include "lib/vrf.h"
-
-/*
- * Helper functions.
- */
-static const char *isis_yang_adj_state(enum isis_adj_state state)
-{
-	switch (state) {
-	case ISIS_ADJ_DOWN:
-		return "down";
-	case ISIS_ADJ_UP:
-		return "up";
-	case ISIS_ADJ_INITIALIZING:
-		return "init";
-	default:
-		return "failed";
-	}
-}
-
-/*
- * XPath: /frr-isisd:isis/instance
- */
-static int isis_instance_create(enum nb_event event,
-				const struct lyd_node *dnode,
-				union nb_resource *resource)
-{
-	struct isis_area *area;
-	const char *area_tag;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	area_tag = yang_dnode_get_string(dnode, "./area-tag");
-	area = isis_area_lookup(area_tag);
-	if (area)
-		return NB_ERR_INCONSISTENCY;
-
-	area = isis_area_create(area_tag);
-	/* save area in dnode to avoid looking it up all the time */
-	nb_running_set_entry(dnode, area);
-
-	return NB_OK;
-}
-
-static int isis_instance_destroy(enum nb_event event,
-				const struct lyd_node *dnode)
-{
-	struct isis_area *area;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	area = nb_running_unset_entry(dnode);
-	isis_area_destroy(area->area_tag);
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/is-type
- */
-static int isis_instance_is_type_modify(enum nb_event event,
-					const struct lyd_node *dnode,
-					union nb_resource *resource)
-{
-	struct isis_area *area;
-	int type;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	area = nb_running_get_entry(dnode, NULL, true);
-	type = yang_dnode_get_enum(dnode, NULL);
-	isis_area_is_type_set(area, type);
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/area-address
- */
-static int isis_instance_area_address_create(enum nb_event event,
-					     const struct lyd_node *dnode,
-					     union nb_resource *resource)
-{
-	struct isis_area *area;
-	struct area_addr addr, *addrr = NULL, *addrp = NULL;
-	struct listnode *node;
-	uint8_t buff[255];
-	const char *net_title = yang_dnode_get_string(dnode, NULL);
-
-	switch (event) {
-	case NB_EV_VALIDATE:
-		addr.addr_len = dotformat2buff(buff, net_title);
-		memcpy(addr.area_addr, buff, addr.addr_len);
-		if (addr.area_addr[addr.addr_len - 1] != 0) {
-			flog_warn(
-				EC_LIB_NB_CB_CONFIG_VALIDATE,
-				"nsel byte (last byte) in area address must be 0");
-			return NB_ERR_VALIDATION;
-		}
-		if (isis->sysid_set) {
-			/* Check that the SystemID portions match */
-			if (memcmp(isis->sysid, GETSYSID((&addr)),
-				   ISIS_SYS_ID_LEN)) {
-				flog_warn(
-					EC_LIB_NB_CB_CONFIG_VALIDATE,
-					"System ID must not change when defining additional area addresses");
-				return NB_ERR_VALIDATION;
-			}
-		}
-		break;
-	case NB_EV_PREPARE:
-		addrr = XMALLOC(MTYPE_ISIS_AREA_ADDR, sizeof(struct area_addr));
-		addrr->addr_len = dotformat2buff(buff, net_title);
-		memcpy(addrr->area_addr, buff, addrr->addr_len);
-		resource->ptr = addrr;
-		break;
-	case NB_EV_ABORT:
-		XFREE(MTYPE_ISIS_AREA_ADDR, resource->ptr);
-		break;
-	case NB_EV_APPLY:
-		area = nb_running_get_entry(dnode, NULL, true);
-		addrr = resource->ptr;
-
-		if (isis->sysid_set == 0) {
-			/*
-			 * First area address - get the SystemID for this router
-			 */
-			memcpy(isis->sysid, GETSYSID(addrr), ISIS_SYS_ID_LEN);
-			isis->sysid_set = 1;
-		} else {
-			/* check that we don't already have this address */
-			for (ALL_LIST_ELEMENTS_RO(area->area_addrs, node,
-						  addrp)) {
-				if ((addrp->addr_len + ISIS_SYS_ID_LEN
-				     + ISIS_NSEL_LEN)
-				    != (addrr->addr_len))
-					continue;
-				if (!memcmp(addrp->area_addr, addrr->area_addr,
-					    addrr->addr_len)) {
-					XFREE(MTYPE_ISIS_AREA_ADDR, addrr);
-					return NB_OK; /* silent fail */
-				}
-			}
-		}
-
-		/*Forget the systemID part of the address */
-		addrr->addr_len -= (ISIS_SYS_ID_LEN + ISIS_NSEL_LEN);
-		assert(area->area_addrs); /* to silence scan-build sillyness */
-		listnode_add(area->area_addrs, addrr);
-
-		/* only now we can safely generate our LSPs for this area */
-		if (listcount(area->area_addrs) > 0) {
-			if (area->is_type & IS_LEVEL_1)
-				lsp_generate(area, IS_LEVEL_1);
-			if (area->is_type & IS_LEVEL_2)
-				lsp_generate(area, IS_LEVEL_2);
-		}
-		break;
-	}
-
-	return NB_OK;
-}
-
-static int isis_instance_area_address_destroy(enum nb_event event,
-					     const struct lyd_node *dnode)
-{
-	struct area_addr addr, *addrp = NULL;
-	struct listnode *node;
-	uint8_t buff[255];
-	struct isis_area *area;
-	const char *net_title;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	net_title = yang_dnode_get_string(dnode, NULL);
-	addr.addr_len = dotformat2buff(buff, net_title);
-	memcpy(addr.area_addr, buff, (int)addr.addr_len);
-	area = nb_running_get_entry(dnode, NULL, true);
-	for (ALL_LIST_ELEMENTS_RO(area->area_addrs, node, addrp)) {
-		if ((addrp->addr_len + ISIS_SYS_ID_LEN + 1) == addr.addr_len
-		    && !memcmp(addrp->area_addr, addr.area_addr, addr.addr_len))
-			break;
-	}
-	if (!addrp)
-		return NB_ERR_INCONSISTENCY;
-
-	listnode_delete(area->area_addrs, addrp);
-	XFREE(MTYPE_ISIS_AREA_ADDR, addrp);
-	/*
-	 * Last area address - reset the SystemID for this router
-	 */
-	if (listcount(area->area_addrs) == 0) {
-		memset(isis->sysid, 0, ISIS_SYS_ID_LEN);
-		isis->sysid_set = 0;
-		if (isis->debugs & DEBUG_EVENTS)
-			zlog_debug("Router has no SystemID");
-	}
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/dynamic-hostname
- */
-static int isis_instance_dynamic_hostname_modify(enum nb_event event,
-						 const struct lyd_node *dnode,
-						 union nb_resource *resource)
-{
-	struct isis_area *area;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	area = nb_running_get_entry(dnode, NULL, true);
-	isis_area_dynhostname_set(area, yang_dnode_get_bool(dnode, NULL));
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/attached
- */
-static int isis_instance_attached_modify(enum nb_event event,
-					 const struct lyd_node *dnode,
-					 union nb_resource *resource)
-{
-	struct isis_area *area;
-	bool attached;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	area = nb_running_get_entry(dnode, NULL, true);
-	attached = yang_dnode_get_bool(dnode, NULL);
-	isis_area_attached_bit_set(area, attached);
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/overload
- */
-static int isis_instance_overload_modify(enum nb_event event,
-					 const struct lyd_node *dnode,
-					 union nb_resource *resource)
-{
-	struct isis_area *area;
-	bool overload;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	area = nb_running_get_entry(dnode, NULL, true);
-	overload = yang_dnode_get_bool(dnode, NULL);
-	isis_area_overload_bit_set(area, overload);
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/metric-style
- */
-static int isis_instance_metric_style_modify(enum nb_event event,
-					     const struct lyd_node *dnode,
-					     union nb_resource *resource)
-{
-	struct isis_area *area;
-	bool old_metric, new_metric;
-	enum isis_metric_style metric_style = yang_dnode_get_enum(dnode, NULL);
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	area = nb_running_get_entry(dnode, NULL, true);
-	old_metric = (metric_style == ISIS_WIDE_METRIC) ? false : true;
-	new_metric = (metric_style == ISIS_NARROW_METRIC) ? false : true;
-	isis_area_metricstyle_set(area, old_metric, new_metric);
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/purge-originator
- */
-static int isis_instance_purge_originator_modify(enum nb_event event,
-						 const struct lyd_node *dnode,
-						 union nb_resource *resource)
-{
-	struct isis_area *area;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	area = nb_running_get_entry(dnode, NULL, true);
-	area->purge_originator = yang_dnode_get_bool(dnode, NULL);
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/lsp/mtu
- */
-static int isis_instance_lsp_mtu_modify(enum nb_event event,
-					const struct lyd_node *dnode,
-					union nb_resource *resource)
-{
-	struct listnode *node;
-	struct isis_circuit *circuit;
-	uint16_t lsp_mtu = yang_dnode_get_uint16(dnode, NULL);
-	struct isis_area *area;
-
-	switch (event) {
-	case NB_EV_VALIDATE:
-		area = nb_running_get_entry(dnode, NULL, false);
-		if (!area)
-			break;
-		for (ALL_LIST_ELEMENTS_RO(area->circuit_list, node, circuit)) {
-			if (circuit->state != C_STATE_INIT
-			    && circuit->state != C_STATE_UP)
-				continue;
-			if (lsp_mtu > isis_circuit_pdu_size(circuit)) {
-				flog_warn(
-					EC_LIB_NB_CB_CONFIG_VALIDATE,
-					"ISIS area contains circuit %s, which has a maximum PDU size of %zu",
-					circuit->interface->name,
-					isis_circuit_pdu_size(circuit));
-				return NB_ERR_VALIDATION;
-			}
-		}
-		break;
-	case NB_EV_PREPARE:
-	case NB_EV_ABORT:
-		break;
-	case NB_EV_APPLY:
-		area = nb_running_get_entry(dnode, NULL, true);
-		isis_area_lsp_mtu_set(area, lsp_mtu);
-		break;
-	}
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/lsp/refresh-interval/level-1
- */
-static int
-isis_instance_lsp_refresh_interval_level_1_modify(enum nb_event event,
-						  const struct lyd_node *dnode,
-						  union nb_resource *resource)
-{
-	struct isis_area *area;
-	uint16_t refr_int;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	refr_int = yang_dnode_get_uint16(dnode, NULL);
-	area = nb_running_get_entry(dnode, NULL, true);
-	isis_area_lsp_refresh_set(area, IS_LEVEL_1, refr_int);
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/lsp/refresh-interval/level-2
- */
-static int
-isis_instance_lsp_refresh_interval_level_2_modify(enum nb_event event,
-						  const struct lyd_node *dnode,
-						  union nb_resource *resource)
-{
-	struct isis_area *area;
-	uint16_t refr_int;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	refr_int = yang_dnode_get_uint16(dnode, NULL);
-	area = nb_running_get_entry(dnode, NULL, true);
-	isis_area_lsp_refresh_set(area, IS_LEVEL_2, refr_int);
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/lsp/maximum-lifetime/level-1
- */
-static int
-isis_instance_lsp_maximum_lifetime_level_1_modify(enum nb_event event,
-						  const struct lyd_node *dnode,
-						  union nb_resource *resource)
-{
-	struct isis_area *area;
-	uint16_t max_lt;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	max_lt = yang_dnode_get_uint16(dnode, NULL);
-	area = nb_running_get_entry(dnode, NULL, true);
-	isis_area_max_lsp_lifetime_set(area, IS_LEVEL_1, max_lt);
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/lsp/maximum-lifetime/level-2
- */
-static int
-isis_instance_lsp_maximum_lifetime_level_2_modify(enum nb_event event,
-						  const struct lyd_node *dnode,
-						  union nb_resource *resource)
-{
-	struct isis_area *area;
-	uint16_t max_lt;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	max_lt = yang_dnode_get_uint16(dnode, NULL);
-	area = nb_running_get_entry(dnode, NULL, true);
-	isis_area_max_lsp_lifetime_set(area, IS_LEVEL_2, max_lt);
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/lsp/generation-interval/level-1
- */
-static int isis_instance_lsp_generation_interval_level_1_modify(
-	enum nb_event event, const struct lyd_node *dnode,
-	union nb_resource *resource)
-{
-	struct isis_area *area;
-	uint16_t gen_int;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	gen_int = yang_dnode_get_uint16(dnode, NULL);
-	area = nb_running_get_entry(dnode, NULL, true);
-	area->lsp_gen_interval[0] = gen_int;
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/lsp/generation-interval/level-2
- */
-static int isis_instance_lsp_generation_interval_level_2_modify(
-	enum nb_event event, const struct lyd_node *dnode,
-	union nb_resource *resource)
-{
-	struct isis_area *area;
-	uint16_t gen_int;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	gen_int = yang_dnode_get_uint16(dnode, NULL);
-	area = nb_running_get_entry(dnode, NULL, true);
-	area->lsp_gen_interval[1] = gen_int;
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/spf/ietf-backoff-delay
- */
-static void ietf_backoff_delay_apply_finish(const struct lyd_node *dnode)
-{
-	long init_delay = yang_dnode_get_uint16(dnode, "./init-delay");
-	long short_delay = yang_dnode_get_uint16(dnode, "./short-delay");
-	long long_delay = yang_dnode_get_uint16(dnode, "./long-delay");
-	long holddown = yang_dnode_get_uint16(dnode, "./hold-down");
-	long timetolearn = yang_dnode_get_uint16(dnode, "./time-to-learn");
-	struct isis_area *area = nb_running_get_entry(dnode, NULL, true);
-	size_t bufsiz = strlen(area->area_tag) + sizeof("IS-IS  Lx");
-	char *buf = XCALLOC(MTYPE_TMP, bufsiz);
-
-	snprintf(buf, bufsiz, "IS-IS %s L1", area->area_tag);
-	spf_backoff_free(area->spf_delay_ietf[0]);
-	area->spf_delay_ietf[0] =
-		spf_backoff_new(master, buf, init_delay, short_delay,
-				long_delay, holddown, timetolearn);
-
-	snprintf(buf, bufsiz, "IS-IS %s L2", area->area_tag);
-	spf_backoff_free(area->spf_delay_ietf[1]);
-	area->spf_delay_ietf[1] =
-		spf_backoff_new(master, buf, init_delay, short_delay,
-				long_delay, holddown, timetolearn);
-
-	XFREE(MTYPE_TMP, buf);
-}
-
-static int
-isis_instance_spf_ietf_backoff_delay_create(enum nb_event event,
-					    const struct lyd_node *dnode,
-					    union nb_resource *resource)
-{
-	/* All the work is done in the apply_finish */
-	return NB_OK;
-}
-
-static int
-isis_instance_spf_ietf_backoff_delay_destroy(enum nb_event event,
-					    const struct lyd_node *dnode)
-{
-	struct isis_area *area;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	area = nb_running_get_entry(dnode, NULL, true);
-	spf_backoff_free(area->spf_delay_ietf[0]);
-	spf_backoff_free(area->spf_delay_ietf[1]);
-	area->spf_delay_ietf[0] = NULL;
-	area->spf_delay_ietf[1] = NULL;
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/spf/ietf-backoff-delay/init-delay
- */
-static int isis_instance_spf_ietf_backoff_delay_init_delay_modify(
-	enum nb_event event, const struct lyd_node *dnode,
-	union nb_resource *resource)
-{
-	/* All the work is done in the apply_finish */
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/spf/ietf-backoff-delay/short-delay
- */
-static int isis_instance_spf_ietf_backoff_delay_short_delay_modify(
-	enum nb_event event, const struct lyd_node *dnode,
-	union nb_resource *resource)
-{
-	/* All the work is done in the apply_finish */
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/spf/ietf-backoff-delay/long-delay
- */
-static int isis_instance_spf_ietf_backoff_delay_long_delay_modify(
-	enum nb_event event, const struct lyd_node *dnode,
-	union nb_resource *resource)
-{
-	/* All the work is done in the apply_finish */
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/spf/ietf-backoff-delay/hold-down
- */
-static int isis_instance_spf_ietf_backoff_delay_hold_down_modify(
-	enum nb_event event, const struct lyd_node *dnode,
-	union nb_resource *resource)
-{
-	/* All the work is done in the apply_finish */
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/spf/ietf-backoff-delay/time-to-learn
- */
-static int isis_instance_spf_ietf_backoff_delay_time_to_learn_modify(
-	enum nb_event event, const struct lyd_node *dnode,
-	union nb_resource *resource)
-{
-	/* All the work is done in the apply_finish */
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/spf/minimum-interval/level-1
- */
-static int
-isis_instance_spf_minimum_interval_level_1_modify(enum nb_event event,
-						  const struct lyd_node *dnode,
-						  union nb_resource *resource)
-{
-	struct isis_area *area;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	area = nb_running_get_entry(dnode, NULL, true);
-	area->min_spf_interval[0] = yang_dnode_get_uint16(dnode, NULL);
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/spf/minimum-interval/level-2
- */
-static int
-isis_instance_spf_minimum_interval_level_2_modify(enum nb_event event,
-						  const struct lyd_node *dnode,
-						  union nb_resource *resource)
-{
-	struct isis_area *area;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	area = nb_running_get_entry(dnode, NULL, true);
-	area->min_spf_interval[1] = yang_dnode_get_uint16(dnode, NULL);
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/area-password
- */
-static void area_password_apply_finish(const struct lyd_node *dnode)
-{
-	const char *password = yang_dnode_get_string(dnode, "./password");
-	struct isis_area *area = nb_running_get_entry(dnode, NULL, true);
-	int pass_type = yang_dnode_get_enum(dnode, "./password-type");
-	uint8_t snp_auth = yang_dnode_get_enum(dnode, "./authenticate-snp");
-
-	switch (pass_type) {
-	case ISIS_PASSWD_TYPE_CLEARTXT:
-		isis_area_passwd_cleartext_set(area, IS_LEVEL_1, password,
-					       snp_auth);
-		break;
-	case ISIS_PASSWD_TYPE_HMAC_MD5:
-		isis_area_passwd_hmac_md5_set(area, IS_LEVEL_1, password,
-					      snp_auth);
-		break;
-	}
-}
-
-static int isis_instance_area_password_create(enum nb_event event,
-					      const struct lyd_node *dnode,
-					      union nb_resource *resource)
-{
-	/* actual setting is done in apply_finish */
-	return NB_OK;
-}
-
-static int isis_instance_area_password_destroy(enum nb_event event,
-					      const struct lyd_node *dnode)
-{
-	struct isis_area *area;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	area = nb_running_get_entry(dnode, NULL, true);
-	isis_area_passwd_unset(area, IS_LEVEL_1);
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/area-password/password
- */
-static int
-isis_instance_area_password_password_modify(enum nb_event event,
-					    const struct lyd_node *dnode,
-					    union nb_resource *resource)
-{
-	/* actual setting is done in apply_finish */
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/area-password/password-type
- */
-static int
-isis_instance_area_password_password_type_modify(enum nb_event event,
-						 const struct lyd_node *dnode,
-						 union nb_resource *resource)
-{
-	/* actual setting is done in apply_finish */
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/area-password/authenticate-snp
- */
-static int isis_instance_area_password_authenticate_snp_modify(
-	enum nb_event event, const struct lyd_node *dnode,
-	union nb_resource *resource)
-{
-	/* actual setting is done in apply_finish */
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/domain-password
- */
-static void domain_password_apply_finish(const struct lyd_node *dnode)
-{
-	const char *password = yang_dnode_get_string(dnode, "./password");
-	struct isis_area *area = nb_running_get_entry(dnode, NULL, true);
-	int pass_type = yang_dnode_get_enum(dnode, "./password-type");
-	uint8_t snp_auth = yang_dnode_get_enum(dnode, "./authenticate-snp");
-
-	switch (pass_type) {
-	case ISIS_PASSWD_TYPE_CLEARTXT:
-		isis_area_passwd_cleartext_set(area, IS_LEVEL_2, password,
-					       snp_auth);
-		break;
-	case ISIS_PASSWD_TYPE_HMAC_MD5:
-		isis_area_passwd_hmac_md5_set(area, IS_LEVEL_2, password,
-					      snp_auth);
-		break;
-	}
-}
-
-static int isis_instance_domain_password_create(enum nb_event event,
-						const struct lyd_node *dnode,
-						union nb_resource *resource)
-{
-	/* actual setting is done in apply_finish */
-	return NB_OK;
-}
-
-static int isis_instance_domain_password_destroy(enum nb_event event,
-						const struct lyd_node *dnode)
-{
-	struct isis_area *area;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	area = nb_running_get_entry(dnode, NULL, true);
-	isis_area_passwd_unset(area, IS_LEVEL_2);
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/domain-password/password
- */
-static int
-isis_instance_domain_password_password_modify(enum nb_event event,
-					      const struct lyd_node *dnode,
-					      union nb_resource *resource)
-{
-	/* actual setting is done in apply_finish */
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/domain-password/password-type
- */
-static int
-isis_instance_domain_password_password_type_modify(enum nb_event event,
-						   const struct lyd_node *dnode,
-						   union nb_resource *resource)
-{
-	/* actual setting is done in apply_finish */
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/domain-password/authenticate-snp
- */
-static int isis_instance_domain_password_authenticate_snp_modify(
-	enum nb_event event, const struct lyd_node *dnode,
-	union nb_resource *resource)
-{
-	/* actual setting is done in apply_finish */
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/default-information-originate/ipv4
- */
-static void default_info_origin_apply_finish(const struct lyd_node *dnode,
-					     int family)
-{
-	int originate_type = DEFAULT_ORIGINATE;
-	unsigned long metric = 0;
-	const char *routemap = NULL;
-	struct isis_area *area = nb_running_get_entry(dnode, NULL, true);
-	int level = yang_dnode_get_enum(dnode, "./level");
-
-	if (yang_dnode_get_bool(dnode, "./always")) {
-		originate_type = DEFAULT_ORIGINATE_ALWAYS;
-	} else if (family == AF_INET6) {
-		zlog_warn(
-			"%s: Zebra doesn't implement default-originate for IPv6 yet, so use with care or use default-originate always.",
-			__func__);
-	}
-
-	if (yang_dnode_exists(dnode, "./metric"))
-		metric = yang_dnode_get_uint32(dnode, "./metric");
-	if (yang_dnode_exists(dnode, "./route-map"))
-		routemap = yang_dnode_get_string(dnode, "./route-map");
-
-	isis_redist_set(area, level, family, DEFAULT_ROUTE, metric, routemap,
-			originate_type);
-}
-
-static void default_info_origin_ipv4_apply_finish(const struct lyd_node *dnode)
-{
-	default_info_origin_apply_finish(dnode, AF_INET);
-}
-
-static void default_info_origin_ipv6_apply_finish(const struct lyd_node *dnode)
-{
-	default_info_origin_apply_finish(dnode, AF_INET6);
-}
-
-static int isis_instance_default_information_originate_ipv4_create(
-	enum nb_event event, const struct lyd_node *dnode,
-	union nb_resource *resource)
-{
-	/* It's all done by default_info_origin_apply_finish */
-	return NB_OK;
-}
-
-static int isis_instance_default_information_originate_ipv4_destroy(
-	enum nb_event event, const struct lyd_node *dnode)
-{
-	struct isis_area *area;
-	int level;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	area = nb_running_get_entry(dnode, NULL, true);
-	level = yang_dnode_get_enum(dnode, "./level");
-	isis_redist_unset(area, level, AF_INET, DEFAULT_ROUTE);
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/default-information-originate/ipv4/always
- */
-static int isis_instance_default_information_originate_ipv4_always_modify(
-	enum nb_event event, const struct lyd_node *dnode,
-	union nb_resource *resource)
-{
-	/* It's all done by default_info_origin_apply_finish */
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/default-information-originate/ipv4/route-map
- */
-static int isis_instance_default_information_originate_ipv4_route_map_modify(
-	enum nb_event event, const struct lyd_node *dnode,
-	union nb_resource *resource)
-{
-	/* It's all done by default_info_origin_apply_finish */
-	return NB_OK;
-}
-
-static int isis_instance_default_information_originate_ipv4_route_map_destroy(
-	enum nb_event event, const struct lyd_node *dnode)
-{
-	/* It's all done by default_info_origin_apply_finish */
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/default-information-originate/ipv4/metric
- */
-static int isis_instance_default_information_originate_ipv4_metric_modify(
-	enum nb_event event, const struct lyd_node *dnode,
-	union nb_resource *resource)
-{
-	/* It's all done by default_info_origin_apply_finish */
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/default-information-originate/ipv6
- */
-static int isis_instance_default_information_originate_ipv6_create(
-	enum nb_event event, const struct lyd_node *dnode,
-	union nb_resource *resource)
-{
-	/* It's all done by default_info_origin_apply_finish */
-	return NB_OK;
-}
-
-static int isis_instance_default_information_originate_ipv6_destroy(
-	enum nb_event event, const struct lyd_node *dnode)
-{
-	struct isis_area *area;
-	int level;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	area = nb_running_get_entry(dnode, NULL, true);
-	level = yang_dnode_get_enum(dnode, "./level");
-	isis_redist_unset(area, level, AF_INET6, DEFAULT_ROUTE);
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/default-information-originate/ipv6/always
- */
-static int isis_instance_default_information_originate_ipv6_always_modify(
-	enum nb_event event, const struct lyd_node *dnode,
-	union nb_resource *resource)
-{
-	/* It's all done by default_info_origin_apply_finish */
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/default-information-originate/ipv6/route-map
- */
-static int isis_instance_default_information_originate_ipv6_route_map_modify(
-	enum nb_event event, const struct lyd_node *dnode,
-	union nb_resource *resource)
-{
-	/* It's all done by default_info_origin_apply_finish */
-	return NB_OK;
-}
-
-static int isis_instance_default_information_originate_ipv6_route_map_destroy(
-	enum nb_event event, const struct lyd_node *dnode)
-{
-	/* It's all done by default_info_origin_apply_finish */
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/default-information-originate/ipv6/metric
- */
-static int isis_instance_default_information_originate_ipv6_metric_modify(
-	enum nb_event event, const struct lyd_node *dnode,
-	union nb_resource *resource)
-{
-	/* It's all done by default_info_origin_apply_finish */
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/redistribute/ipv4
- */
-static void redistribute_apply_finish(const struct lyd_node *dnode, int family)
-{
-	assert(family == AF_INET || family == AF_INET6);
-	int type, level;
-	unsigned long metric = 0;
-	const char *routemap = NULL;
-	struct isis_area *area;
-
-	type = yang_dnode_get_enum(dnode, "./protocol");
-	level = yang_dnode_get_enum(dnode, "./level");
-	area = nb_running_get_entry(dnode, NULL, true);
-
-	if (yang_dnode_exists(dnode, "./metric"))
-		metric = yang_dnode_get_uint32(dnode, "./metric");
-	if (yang_dnode_exists(dnode, "./route-map"))
-		routemap = yang_dnode_get_string(dnode, "./route-map");
-
-	isis_redist_set(area, level, family, type, metric, routemap, 0);
-}
-
-static void redistribute_ipv4_apply_finish(const struct lyd_node *dnode)
-{
-	redistribute_apply_finish(dnode, AF_INET);
-}
-
-static void redistribute_ipv6_apply_finish(const struct lyd_node *dnode)
-{
-	redistribute_apply_finish(dnode, AF_INET6);
-}
-
-static int isis_instance_redistribute_ipv4_create(enum nb_event event,
-						  const struct lyd_node *dnode,
-						  union nb_resource *resource)
-{
-	/* It's all done by redistribute_apply_finish */
-	return NB_OK;
-}
-
-static int isis_instance_redistribute_ipv4_destroy(enum nb_event event,
-						  const struct lyd_node *dnode)
-{
-	struct isis_area *area;
-	int level, type;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	area = nb_running_get_entry(dnode, NULL, true);
-	level = yang_dnode_get_enum(dnode, "./level");
-	type = yang_dnode_get_enum(dnode, "./protocol");
-	isis_redist_unset(area, level, AF_INET, type);
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/redistribute/ipv4/route-map
- */
-static int
-isis_instance_redistribute_ipv4_route_map_modify(enum nb_event event,
-						 const struct lyd_node *dnode,
-						 union nb_resource *resource)
-{
-	/* It's all done by redistribute_apply_finish */
-	return NB_OK;
-}
-
-static int
-isis_instance_redistribute_ipv4_route_map_destroy(enum nb_event event,
-						 const struct lyd_node *dnode)
-{
-	/* It's all done by redistribute_apply_finish */
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/redistribute/ipv4/metric
- */
-static int
-isis_instance_redistribute_ipv4_metric_modify(enum nb_event event,
-					      const struct lyd_node *dnode,
-					      union nb_resource *resource)
-{
-	/* It's all done by redistribute_apply_finish */
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/redistribute/ipv6
- */
-static int isis_instance_redistribute_ipv6_create(enum nb_event event,
-						  const struct lyd_node *dnode,
-						  union nb_resource *resource)
-{
-	/* It's all done by redistribute_apply_finish */
-	return NB_OK;
-}
-
-static int isis_instance_redistribute_ipv6_destroy(enum nb_event event,
-						  const struct lyd_node *dnode)
-{
-	struct isis_area *area;
-	int level, type;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	area = nb_running_get_entry(dnode, NULL, true);
-	level = yang_dnode_get_enum(dnode, "./level");
-	type = yang_dnode_get_enum(dnode, "./protocol");
-	isis_redist_unset(area, level, AF_INET6, type);
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/redistribute/ipv6/route-map
- */
-static int
-isis_instance_redistribute_ipv6_route_map_modify(enum nb_event event,
-						 const struct lyd_node *dnode,
-						 union nb_resource *resource)
-{
-	/* It's all done by redistribute_apply_finish */
-	return NB_OK;
-}
-
-static int
-isis_instance_redistribute_ipv6_route_map_destroy(enum nb_event event,
-						 const struct lyd_node *dnode)
-{
-	/* It's all done by redistribute_apply_finish */
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/redistribute/ipv6/metric
- */
-static int
-isis_instance_redistribute_ipv6_metric_modify(enum nb_event event,
-					      const struct lyd_node *dnode,
-					      union nb_resource *resource)
-{
-	/* It's all done by redistribute_apply_finish */
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/multi-topology/ipv4-multicast
- */
-static int isis_multi_topology_common(enum nb_event event,
-				      const struct lyd_node *dnode,
-				      const char *topology, bool create)
-{
-	struct isis_area *area;
-	struct isis_area_mt_setting *setting;
-	uint16_t mtid = isis_str2mtid(topology);
-
-	switch (event) {
-	case NB_EV_VALIDATE:
-		if (mtid == (uint16_t)-1) {
-			flog_warn(EC_LIB_NB_CB_CONFIG_VALIDATE,
-				  "Unknown topology %s", topology);
-			return NB_ERR_VALIDATION;
-		}
-		break;
-	case NB_EV_PREPARE:
-	case NB_EV_ABORT:
-		break;
-	case NB_EV_APPLY:
-		area = nb_running_get_entry(dnode, NULL, true);
-		setting = area_get_mt_setting(area, mtid);
-		setting->enabled = create;
-		lsp_regenerate_schedule(area, IS_LEVEL_1 | IS_LEVEL_2, 0);
-		break;
-	}
-
-	return NB_OK;
-}
-
-static int isis_multi_topology_overload_common(enum nb_event event,
-					       const struct lyd_node *dnode,
-					       const char *topology)
-{
-	struct isis_area *area;
-	struct isis_area_mt_setting *setting;
-	uint16_t mtid = isis_str2mtid(topology);
-
-	/* validation is done in isis_multi_topology_common */
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	area = nb_running_get_entry(dnode, NULL, true);
-	setting = area_get_mt_setting(area, mtid);
-	setting->overload = yang_dnode_get_bool(dnode, NULL);
-	if (setting->enabled)
-		lsp_regenerate_schedule(area, IS_LEVEL_1 | IS_LEVEL_2, 0);
-
-	return NB_OK;
-}
-
-static int
-isis_instance_multi_topology_ipv4_multicast_create(enum nb_event event,
-						   const struct lyd_node *dnode,
-						   union nb_resource *resource)
-{
-	return isis_multi_topology_common(event, dnode, "ipv4-multicast", true);
-}
-
-static int
-isis_instance_multi_topology_ipv4_multicast_destroy(enum nb_event event,
-						   const struct lyd_node *dnode)
-{
-	return isis_multi_topology_common(event, dnode, "ipv4-multicast",
-					  false);
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/multi-topology/ipv4-multicast/overload
- */
-static int isis_instance_multi_topology_ipv4_multicast_overload_modify(
-	enum nb_event event, const struct lyd_node *dnode,
-	union nb_resource *resource)
-{
-	return isis_multi_topology_overload_common(event, dnode,
-						   "ipv4-multicast");
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/multi-topology/ipv4-management
- */
-static int isis_instance_multi_topology_ipv4_management_create(
-	enum nb_event event, const struct lyd_node *dnode,
-	union nb_resource *resource)
-{
-	return isis_multi_topology_common(event, dnode, "ipv4-mgmt", true);
-}
-
-static int isis_instance_multi_topology_ipv4_management_destroy(
-	enum nb_event event, const struct lyd_node *dnode)
-{
-	return isis_multi_topology_common(event, dnode, "ipv4-mgmt", false);
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/multi-topology/ipv4-management/overload
- */
-static int isis_instance_multi_topology_ipv4_management_overload_modify(
-	enum nb_event event, const struct lyd_node *dnode,
-	union nb_resource *resource)
-{
-	return isis_multi_topology_overload_common(event, dnode, "ipv4-mgmt");
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/multi-topology/ipv6-unicast
- */
-static int
-isis_instance_multi_topology_ipv6_unicast_create(enum nb_event event,
-						 const struct lyd_node *dnode,
-						 union nb_resource *resource)
-{
-	return isis_multi_topology_common(event, dnode, "ipv6-unicast", true);
-}
-
-static int
-isis_instance_multi_topology_ipv6_unicast_destroy(enum nb_event event,
-						 const struct lyd_node *dnode)
-{
-	return isis_multi_topology_common(event, dnode, "ipv6-unicast", false);
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/multi-topology/ipv6-unicast/overload
- */
-static int isis_instance_multi_topology_ipv6_unicast_overload_modify(
-	enum nb_event event, const struct lyd_node *dnode,
-	union nb_resource *resource)
-{
-	return isis_multi_topology_overload_common(event, dnode,
-						   "ipv6-unicast");
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/multi-topology/ipv6-multicast
- */
-static int
-isis_instance_multi_topology_ipv6_multicast_create(enum nb_event event,
-						   const struct lyd_node *dnode,
-						   union nb_resource *resource)
-{
-	return isis_multi_topology_common(event, dnode, "ipv6-multicast", true);
-}
-
-static int
-isis_instance_multi_topology_ipv6_multicast_destroy(enum nb_event event,
-						   const struct lyd_node *dnode)
-{
-	return isis_multi_topology_common(event, dnode, "ipv6-multicast",
-					  false);
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/multi-topology/ipv6-multicast/overload
- */
-static int isis_instance_multi_topology_ipv6_multicast_overload_modify(
-	enum nb_event event, const struct lyd_node *dnode,
-	union nb_resource *resource)
-{
-	return isis_multi_topology_overload_common(event, dnode,
-						   "ipv6-multicast");
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/multi-topology/ipv6-management
- */
-static int isis_instance_multi_topology_ipv6_management_create(
-	enum nb_event event, const struct lyd_node *dnode,
-	union nb_resource *resource)
-{
-	return isis_multi_topology_common(event, dnode, "ipv6-mgmt", true);
-}
-
-static int isis_instance_multi_topology_ipv6_management_destroy(
-	enum nb_event event, const struct lyd_node *dnode)
-{
-	return isis_multi_topology_common(event, dnode, "ipv6-mgmt", false);
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/multi-topology/ipv6-management/overload
- */
-static int isis_instance_multi_topology_ipv6_management_overload_modify(
-	enum nb_event event, const struct lyd_node *dnode,
-	union nb_resource *resource)
-{
-	return isis_multi_topology_overload_common(event, dnode, "ipv6-mgmt");
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/multi-topology/ipv6-dstsrc
- */
-static int
-isis_instance_multi_topology_ipv6_dstsrc_create(enum nb_event event,
-						const struct lyd_node *dnode,
-						union nb_resource *resource)
-{
-	return isis_multi_topology_common(event, dnode, "ipv6-dstsrc", true);
-}
-
-static int
-isis_instance_multi_topology_ipv6_dstsrc_destroy(enum nb_event event,
-						const struct lyd_node *dnode)
-{
-	return isis_multi_topology_common(event, dnode, "ipv6-dstsrc", false);
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/multi-topology/ipv6-dstsrc/overload
- */
-static int isis_instance_multi_topology_ipv6_dstsrc_overload_modify(
-	enum nb_event event, const struct lyd_node *dnode,
-	union nb_resource *resource)
-{
-	return isis_multi_topology_overload_common(event, dnode, "ipv6-dstsrc");
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/log-adjacency-changes
- */
-static int
-isis_instance_log_adjacency_changes_modify(enum nb_event event,
-					   const struct lyd_node *dnode,
-					   union nb_resource *resource)
-{
-	struct isis_area *area;
-	bool log = yang_dnode_get_bool(dnode, NULL);
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	area = nb_running_get_entry(dnode, NULL, true);
-	area->log_adj_changes = log ? 1 : 0;
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/mpls-te
- */
-static int isis_instance_mpls_te_create(enum nb_event event,
-			       const struct lyd_node *dnode,
-			       union nb_resource *resource)
-{
-	struct listnode *node;
-	struct isis_area *area;
-	struct isis_circuit *circuit;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	area = nb_running_get_entry(dnode, NULL, true);
-	if (area->mta == NULL) {
-
-		struct mpls_te_area *new;
-
-		zlog_debug("ISIS-TE(%s): Initialize MPLS Traffic Engineering",
-			area->area_tag);
-
-		new = XCALLOC(MTYPE_ISIS_MPLS_TE, sizeof(struct mpls_te_area));
-
-		/* Initialize MPLS_TE structure */
-		new->status = enable;
-		new->level = 0;
-		new->inter_as = off;
-		new->interas_areaid.s_addr = 0;
-		new->router_id.s_addr = 0;
-
-		area->mta = new;
-	} else {
-		area->mta->status = enable;
-	}
-
-	/* Update Extended TLVs according to Interface link parameters */
-	for (ALL_LIST_ELEMENTS_RO(area->circuit_list, node, circuit))
-		isis_link_params_update(circuit, circuit->interface);
-
-	/* Reoriginate STD_TE & GMPLS circuits */
-	lsp_regenerate_schedule(area, area->is_type, 0);
-
-	return NB_OK;
-}
-
-static int isis_instance_mpls_te_destroy(enum nb_event event,
-			       const struct lyd_node *dnode)
-{
-	struct listnode *node;
-	struct isis_area *area;
-	struct isis_circuit *circuit;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	area = nb_running_get_entry(dnode, NULL, true);
-	if (IS_MPLS_TE(area->mta))
-		area->mta->status = disable;
-	else
-		return NB_OK;
-
-	/* Flush LSP if circuit engage */
-	for (ALL_LIST_ELEMENTS_RO(area->circuit_list, node, circuit)) {
-		if (!IS_EXT_TE(circuit->ext))
-			continue;
-
-		/* disable MPLS_TE Circuit keeping SR one's */
-		if (IS_SUBTLV(circuit->ext, EXT_ADJ_SID))
-			circuit->ext->status = EXT_ADJ_SID;
-		else if (IS_SUBTLV(circuit->ext, EXT_LAN_ADJ_SID))
-			circuit->ext->status = EXT_LAN_ADJ_SID;
-		else
-			circuit->ext->status = 0;
-	}
-
-	/* Reoriginate STD_TE & GMPLS circuits */
-	lsp_regenerate_schedule(area, area->is_type, 0);
-
-	zlog_debug("ISIS-TE(%s): Disabled MPLS Traffic Engineering",
-		   area->area_tag);
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-isisd:isis/instance/mpls-te/router-address
- */
-static int isis_instance_mpls_te_router_address_modify(enum nb_event event,
-					      const struct lyd_node *dnode,
-					      union nb_resource *resource)
-{
-	struct in_addr value;
-	struct isis_area *area;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	area = nb_running_get_entry(dnode, NULL, true);
-	/* only proceed if MPLS-TE is enabled */
-	if (!IS_MPLS_TE(area->mta))
-		return NB_OK;
-
-	/* Update Area Router ID */
-	yang_dnode_get_ipv4(&value, dnode, NULL);
-	area->mta->router_id.s_addr = value.s_addr;
-
-	/* And re-schedule LSP update */
-	lsp_regenerate_schedule(area, area->is_type, 0);
-
-	return NB_OK;
-}
-
-static int isis_instance_mpls_te_router_address_destroy(enum nb_event event,
-					      const struct lyd_node *dnode)
-{
-	struct isis_area *area;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	area = nb_running_get_entry(dnode, NULL, true);
-	/* only proceed if MPLS-TE is enabled */
-	if (!IS_MPLS_TE(area->mta))
-		return NB_OK;
-
-	/* Reset Area Router ID */
-	area->mta->router_id.s_addr = INADDR_ANY;
-
-	/* And re-schedule LSP update */
-	lsp_regenerate_schedule(area, area->is_type, 0);
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-interface:lib/interface/frr-isisd:isis
- */
-static int lib_interface_isis_create(enum nb_event event,
-				     const struct lyd_node *dnode,
-				     union nb_resource *resource)
-{
-	struct isis_area *area;
-	struct interface *ifp;
-	struct isis_circuit *circuit;
-	const char *area_tag = yang_dnode_get_string(dnode, "./area-tag");
-	uint32_t min_mtu, actual_mtu;
-
-	switch (event) {
-	case NB_EV_PREPARE:
-	case NB_EV_ABORT:
-		break;
-	case NB_EV_VALIDATE:
-		/* check if interface mtu is sufficient. If the area has not
-		 * been created yet, assume default MTU for the area
-		 */
-		ifp = nb_running_get_entry(dnode, NULL, false);
-		/* zebra might not know yet about the MTU - nothing we can do */
-		if (!ifp || ifp->mtu == 0)
-			break;
-		actual_mtu =
-			if_is_broadcast(ifp) ? ifp->mtu - LLC_LEN : ifp->mtu;
-		area = isis_area_lookup(area_tag);
-		if (area)
-			min_mtu = area->lsp_mtu;
-		else
-#ifndef FABRICD
-			min_mtu = yang_get_default_uint16(
-				"/frr-isisd:isis/instance/lsp/mtu");
-#else
-			min_mtu = DEFAULT_LSP_MTU;
-#endif /* ifndef FABRICD */
-		if (actual_mtu < min_mtu) {
-			flog_warn(EC_LIB_NB_CB_CONFIG_VALIDATE,
-				  "Interface %s has MTU %" PRIu32
-				  ", minimum MTU for the area is %" PRIu32 "",
-				  ifp->name, actual_mtu, min_mtu);
-			return NB_ERR_VALIDATION;
-		}
-		break;
-	case NB_EV_APPLY:
-		area = isis_area_lookup(area_tag);
-		/* The area should have already be created. We are
-		 * setting the priority of the global isis area creation
-		 * slightly lower, so it should be executed first, but I
-		 * cannot rely on that so here I have to check.
-		 */
-		if (!area) {
-			flog_err(
-				EC_LIB_NB_CB_CONFIG_APPLY,
-				"%s: attempt to create circuit for area %s before the area has been created",
-				__func__, area_tag);
-			abort();
-		}
-
-		ifp = nb_running_get_entry(dnode, NULL, true);
-		circuit = isis_circuit_create(area, ifp);
-		assert(circuit
-		       && (circuit->state == C_STATE_CONF
-			   || circuit->state == C_STATE_UP));
-		nb_running_set_entry(dnode, circuit);
-		break;
-	}
-
-	return NB_OK;
-}
-
-static int lib_interface_isis_destroy(enum nb_event event,
-				     const struct lyd_node *dnode)
-{
-	struct isis_circuit *circuit;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	circuit = nb_running_unset_entry(dnode);
-	if (!circuit)
-		return NB_ERR_INCONSISTENCY;
-	if (circuit->state == C_STATE_UP || circuit->state == C_STATE_CONF)
-		isis_csm_state_change(ISIS_DISABLE, circuit, circuit->area);
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-interface:lib/interface/frr-isisd:isis/area-tag
- */
-static int lib_interface_isis_area_tag_modify(enum nb_event event,
-					      const struct lyd_node *dnode,
-					      union nb_resource *resource)
-{
-	struct isis_circuit *circuit;
-	struct interface *ifp;
-	struct vrf *vrf;
-	const char *area_tag, *ifname, *vrfname;
-
-	if (event == NB_EV_VALIDATE) {
-		/* libyang doesn't like relative paths across module boundaries
-		 */
-		ifname = yang_dnode_get_string(dnode->parent->parent, "./name");
-		vrfname = yang_dnode_get_string(dnode->parent->parent, "./vrf");
-		vrf = vrf_lookup_by_name(vrfname);
-		assert(vrf);
-		ifp = if_lookup_by_name(ifname, vrf->vrf_id);
-		if (!ifp)
-			return NB_OK;
-		circuit = circuit_lookup_by_ifp(ifp, isis->init_circ_list);
-		area_tag = yang_dnode_get_string(dnode, NULL);
-		if (circuit && circuit->area && circuit->area->area_tag
-		    && strcmp(circuit->area->area_tag, area_tag)) {
-			flog_warn(EC_LIB_NB_CB_CONFIG_VALIDATE,
-				  "ISIS circuit is already defined on %s",
-				  circuit->area->area_tag);
-			return NB_ERR_VALIDATION;
-		}
-	}
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-interface:lib/interface/frr-isisd:isis/circuit-type
- */
-static int lib_interface_isis_circuit_type_modify(enum nb_event event,
-						  const struct lyd_node *dnode,
-						  union nb_resource *resource)
-{
-	int circ_type = yang_dnode_get_enum(dnode, NULL);
-	struct isis_circuit *circuit;
-	struct interface *ifp;
-	struct vrf *vrf;
-	const char *ifname, *vrfname;
-
-	switch (event) {
-	case NB_EV_VALIDATE:
-		/* libyang doesn't like relative paths across module boundaries
-		 */
-		ifname = yang_dnode_get_string(dnode->parent->parent, "./name");
-		vrfname = yang_dnode_get_string(dnode->parent->parent, "./vrf");
-		vrf = vrf_lookup_by_name(vrfname);
-		assert(vrf);
-		ifp = if_lookup_by_name(ifname, vrf->vrf_id);
-		if (!ifp)
-			break;
-		circuit = circuit_lookup_by_ifp(ifp, isis->init_circ_list);
-		if (circuit && circuit->state == C_STATE_UP
-		    && circuit->area->is_type != IS_LEVEL_1_AND_2
-		    && circuit->area->is_type != circ_type) {
-			flog_warn(EC_LIB_NB_CB_CONFIG_VALIDATE,
-				  "Invalid circuit level for area %s",
-				  circuit->area->area_tag);
-			return NB_ERR_VALIDATION;
-		}
-		break;
-	case NB_EV_PREPARE:
-	case NB_EV_ABORT:
-		break;
-	case NB_EV_APPLY:
-		circuit = nb_running_get_entry(dnode, NULL, true);
-		isis_circuit_is_type_set(circuit, circ_type);
-		break;
-	}
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-interface:lib/interface/frr-isisd:isis/ipv4-routing
- */
-static int lib_interface_isis_ipv4_routing_modify(enum nb_event event,
-						  const struct lyd_node *dnode,
-						  union nb_resource *resource)
-{
-	bool ipv4, ipv6;
-	struct isis_circuit *circuit;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	circuit = nb_running_get_entry(dnode, NULL, true);
-	ipv4 = yang_dnode_get_bool(dnode, NULL);
-	ipv6 = yang_dnode_get_bool(dnode, "../ipv6-routing");
-	isis_circuit_af_set(circuit, ipv4, ipv6);
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-interface:lib/interface/frr-isisd:isis/ipv6-routing
- */
-static int lib_interface_isis_ipv6_routing_modify(enum nb_event event,
-						  const struct lyd_node *dnode,
-						  union nb_resource *resource)
-{
-	bool ipv4, ipv6;
-	struct isis_circuit *circuit;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	circuit = nb_running_get_entry(dnode, NULL, true);
-	ipv4 = yang_dnode_exists(dnode, "../ipv4-routing");
-	ipv6 = yang_dnode_get_bool(dnode, NULL);
-	isis_circuit_af_set(circuit, ipv4, ipv6);
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-interface:lib/interface/frr-isisd:isis/bfd-monitoring
- */
-static int lib_interface_isis_bfd_monitoring_modify(enum nb_event event,
-						    const struct lyd_node *dnode,
-						    union nb_resource *resource)
-{
-	struct isis_circuit *circuit;
-	bool bfd_monitoring;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	circuit = nb_running_get_entry(dnode, NULL, true);
-	bfd_monitoring = yang_dnode_get_bool(dnode, NULL);
-
-	if (bfd_monitoring) {
-		isis_bfd_circuit_param_set(circuit, BFD_DEF_MIN_RX,
-					   BFD_DEF_MIN_TX, BFD_DEF_DETECT_MULT,
-					   true);
-	} else {
-		isis_bfd_circuit_cmd(circuit, ZEBRA_BFD_DEST_DEREGISTER);
-		bfd_info_free(&circuit->bfd_info);
-	}
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-interface:lib/interface/frr-isisd:isis/csnp-interval/level-1
- */
-static int
-lib_interface_isis_csnp_interval_level_1_modify(enum nb_event event,
-						const struct lyd_node *dnode,
-						union nb_resource *resource)
-{
-	struct isis_circuit *circuit;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	circuit = nb_running_get_entry(dnode, NULL, true);
-	circuit->csnp_interval[0] = yang_dnode_get_uint16(dnode, NULL);
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-interface:lib/interface/frr-isisd:isis/csnp-interval/level-2
- */
-static int
-lib_interface_isis_csnp_interval_level_2_modify(enum nb_event event,
-						const struct lyd_node *dnode,
-						union nb_resource *resource)
-{
-	struct isis_circuit *circuit;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	circuit = nb_running_get_entry(dnode, NULL, true);
-	circuit->csnp_interval[1] = yang_dnode_get_uint16(dnode, NULL);
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-interface:lib/interface/frr-isisd:isis/psnp-interval/level-1
- */
-static int
-lib_interface_isis_psnp_interval_level_1_modify(enum nb_event event,
-						const struct lyd_node *dnode,
-						union nb_resource *resource)
-{
-	struct isis_circuit *circuit;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	circuit = nb_running_get_entry(dnode, NULL, true);
-	circuit->psnp_interval[0] = yang_dnode_get_uint16(dnode, NULL);
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-interface:lib/interface/frr-isisd:isis/psnp-interval/level-2
- */
-static int
-lib_interface_isis_psnp_interval_level_2_modify(enum nb_event event,
-						const struct lyd_node *dnode,
-						union nb_resource *resource)
-{
-	struct isis_circuit *circuit;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	circuit = nb_running_get_entry(dnode, NULL, true);
-	circuit->psnp_interval[1] = yang_dnode_get_uint16(dnode, NULL);
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-interface:lib/interface/frr-isisd:isis/hello/padding
- */
-static int lib_interface_isis_hello_padding_modify(enum nb_event event,
-						   const struct lyd_node *dnode,
-						   union nb_resource *resource)
-{
-	struct isis_circuit *circuit;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	circuit = nb_running_get_entry(dnode, NULL, true);
-	circuit->pad_hellos = yang_dnode_get_bool(dnode, NULL);
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-interface:lib/interface/frr-isisd:isis/hello/interval/level-1
- */
-static int
-lib_interface_isis_hello_interval_level_1_modify(enum nb_event event,
-						 const struct lyd_node *dnode,
-						 union nb_resource *resource)
-{
-	struct isis_circuit *circuit;
-	uint32_t interval;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	circuit = nb_running_get_entry(dnode, NULL, true);
-	interval = yang_dnode_get_uint32(dnode, NULL);
-	circuit->hello_interval[0] = interval;
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-interface:lib/interface/frr-isisd:isis/hello/interval/level-2
- */
-static int
-lib_interface_isis_hello_interval_level_2_modify(enum nb_event event,
-						 const struct lyd_node *dnode,
-						 union nb_resource *resource)
-{
-	struct isis_circuit *circuit;
-	uint32_t interval;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	circuit = nb_running_get_entry(dnode, NULL, true);
-	interval = yang_dnode_get_uint32(dnode, NULL);
-	circuit->hello_interval[1] = interval;
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-interface:lib/interface/frr-isisd:isis/hello/multiplier/level-1
- */
-static int
-lib_interface_isis_hello_multiplier_level_1_modify(enum nb_event event,
-						   const struct lyd_node *dnode,
-						   union nb_resource *resource)
-{
-	struct isis_circuit *circuit;
-	uint16_t multi;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	circuit = nb_running_get_entry(dnode, NULL, true);
-	multi = yang_dnode_get_uint16(dnode, NULL);
-	circuit->hello_multiplier[0] = multi;
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-interface:lib/interface/frr-isisd:isis/hello/multiplier/level-2
- */
-static int
-lib_interface_isis_hello_multiplier_level_2_modify(enum nb_event event,
-						   const struct lyd_node *dnode,
-						   union nb_resource *resource)
-{
-	struct isis_circuit *circuit;
-	uint16_t multi;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	circuit = nb_running_get_entry(dnode, NULL, true);
-	multi = yang_dnode_get_uint16(dnode, NULL);
-	circuit->hello_multiplier[1] = multi;
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-interface:lib/interface/frr-isisd:isis/metric/level-1
- */
-static int
-lib_interface_isis_metric_level_1_modify(enum nb_event event,
-					 const struct lyd_node *dnode,
-					 union nb_resource *resource)
-{
-	struct isis_circuit *circuit;
-	unsigned int met;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	circuit = nb_running_get_entry(dnode, NULL, true);
-	met = yang_dnode_get_uint32(dnode, NULL);
-	isis_circuit_metric_set(circuit, IS_LEVEL_1, met);
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-interface:lib/interface/frr-isisd:isis/metric/level-2
- */
-static int
-lib_interface_isis_metric_level_2_modify(enum nb_event event,
-					 const struct lyd_node *dnode,
-					 union nb_resource *resource)
-{
-	struct isis_circuit *circuit;
-	unsigned int met;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	circuit = nb_running_get_entry(dnode, NULL, true);
-	met = yang_dnode_get_uint32(dnode, NULL);
-	isis_circuit_metric_set(circuit, IS_LEVEL_2, met);
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-interface:lib/interface/frr-isisd:isis/priority/level-1
- */
-static int
-lib_interface_isis_priority_level_1_modify(enum nb_event event,
-					   const struct lyd_node *dnode,
-					   union nb_resource *resource)
-{
-	struct isis_circuit *circuit;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	circuit = nb_running_get_entry(dnode, NULL, true);
-	circuit->priority[0] = yang_dnode_get_uint8(dnode, NULL);
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-interface:lib/interface/frr-isisd:isis/priority/level-2
- */
-static int
-lib_interface_isis_priority_level_2_modify(enum nb_event event,
-					   const struct lyd_node *dnode,
-					   union nb_resource *resource)
-{
-	struct isis_circuit *circuit;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	circuit = nb_running_get_entry(dnode, NULL, true);
-	circuit->priority[1] = yang_dnode_get_uint8(dnode, NULL);
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-interface:lib/interface/frr-isisd:isis/network-type
- */
-static int lib_interface_isis_network_type_modify(enum nb_event event,
-						  const struct lyd_node *dnode,
-						  union nb_resource *resource)
-{
-	struct isis_circuit *circuit;
-	int net_type = yang_dnode_get_enum(dnode, NULL);
-
-	switch (event) {
-	case NB_EV_VALIDATE:
-		circuit = nb_running_get_entry(dnode, NULL, false);
-		if (!circuit)
-			break;
-		if (circuit->circ_type == CIRCUIT_T_LOOPBACK) {
-			flog_warn(
-				EC_LIB_NB_CB_CONFIG_VALIDATE,
-				"Cannot change network type on loopback interface");
-			return NB_ERR_VALIDATION;
-		}
-		if (net_type == CIRCUIT_T_BROADCAST
-		    && circuit->state == C_STATE_UP
-		    && !if_is_broadcast(circuit->interface)) {
-			flog_warn(
-				EC_LIB_NB_CB_CONFIG_VALIDATE,
-				"Cannot configure non-broadcast interface for broadcast operation");
-			return NB_ERR_VALIDATION;
-		}
-		break;
-	case NB_EV_PREPARE:
-	case NB_EV_ABORT:
-		break;
-	case NB_EV_APPLY:
-		circuit = nb_running_get_entry(dnode, NULL, true);
-		isis_circuit_circ_type_set(circuit, net_type);
-		break;
-	}
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-interface:lib/interface/frr-isisd:isis/passive
- */
-static int lib_interface_isis_passive_modify(enum nb_event event,
-					     const struct lyd_node *dnode,
-					     union nb_resource *resource)
-{
-	struct isis_circuit *circuit;
-	struct isis_area *area;
-	struct interface *ifp;
-	bool passive = yang_dnode_get_bool(dnode, NULL);
-
-	/* validation only applies if we are setting passive to false */
-	if (!passive && event == NB_EV_VALIDATE) {
-		circuit = nb_running_get_entry(dnode, NULL, false);
-		if (!circuit)
-			return NB_OK;
-		ifp = circuit->interface;
-		if (!ifp)
-			return NB_OK;
-		if (if_is_loopback(ifp)) {
-			flog_warn(EC_LIB_NB_CB_CONFIG_VALIDATE,
-				  "Loopback is always passive");
-			return NB_ERR_VALIDATION;
-		}
-	}
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	circuit = nb_running_get_entry(dnode, NULL, true);
-	if (circuit->state != C_STATE_UP) {
-		circuit->is_passive = passive;
-	} else {
-		area = circuit->area;
-		isis_csm_state_change(ISIS_DISABLE, circuit, area);
-		circuit->is_passive = passive;
-		isis_csm_state_change(ISIS_ENABLE, circuit, area);
-	}
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-interface:lib/interface/frr-isisd:isis/password
- */
-static int lib_interface_isis_password_create(enum nb_event event,
-					      const struct lyd_node *dnode,
-					      union nb_resource *resource)
-{
-	return NB_OK;
-}
-
-static int lib_interface_isis_password_destroy(enum nb_event event,
-					      const struct lyd_node *dnode)
-{
-	struct isis_circuit *circuit;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	circuit = nb_running_get_entry(dnode, NULL, true);
-	isis_circuit_passwd_unset(circuit);
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-interface:lib/interface/frr-isisd:isis/password/password
- */
-static int
-lib_interface_isis_password_password_modify(enum nb_event event,
-					    const struct lyd_node *dnode,
-					    union nb_resource *resource)
-{
-	struct isis_circuit *circuit;
-	const char *password;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	password = yang_dnode_get_string(dnode, NULL);
-	circuit = nb_running_get_entry(dnode, NULL, true);
-
-	isis_circuit_passwd_set(circuit, circuit->passwd.type, password);
-
-	return NB_OK;
-}
-
-/*
- * XPath: /frr-interface:lib/interface/frr-isisd:isis/password/password-type
- */
-static int
-lib_interface_isis_password_password_type_modify(enum nb_event event,
-						 const struct lyd_node *dnode,
-						 union nb_resource *resource)
-{
-	struct isis_circuit *circuit;
-	uint8_t pass_type;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	pass_type = yang_dnode_get_enum(dnode, NULL);
-	circuit = nb_running_get_entry(dnode, NULL, true);
-	circuit->passwd.type = pass_type;
-
-	return NB_OK;
-}
-
-/*
- * XPath:
- * /frr-interface:lib/interface/frr-isisd:isis/disable-three-way-handshake
- */
-static int lib_interface_isis_disable_three_way_handshake_modify(
-	enum nb_event event, const struct lyd_node *dnode,
-	union nb_resource *resource)
-{
-	struct isis_circuit *circuit;
-
-	if (event != NB_EV_APPLY)
-		return NB_OK;
-
-	circuit = nb_running_get_entry(dnode, NULL, true);
-	circuit->disable_threeway_adj = yang_dnode_get_bool(dnode, NULL);
-
-	return NB_OK;
-}
-
-/*
- * XPath:
- * /frr-interface:lib/interface/frr-isisd:isis/multi-topology/ipv4-unicast
- */
-static int lib_interface_isis_multi_topology_common(
-	enum nb_event event, const struct lyd_node *dnode, uint16_t mtid)
-{
-	struct isis_circuit *circuit;
-	bool value;
-
-	switch (event) {
-	case NB_EV_VALIDATE:
-		circuit = nb_running_get_entry(dnode, NULL, false);
-		if (circuit && circuit->area && circuit->area->oldmetric) {
-			flog_warn(
-				EC_LIB_NB_CB_CONFIG_VALIDATE,
-				"Multi topology IS-IS can only be used with wide metrics");
-			return NB_ERR_VALIDATION;
-		}
-		break;
-	case NB_EV_PREPARE:
-	case NB_EV_ABORT:
-		break;
-	case NB_EV_APPLY:
-		circuit = nb_running_get_entry(dnode, NULL, true);
-		value = yang_dnode_get_bool(dnode, NULL);
-		isis_circuit_mt_enabled_set(circuit, mtid, value);
-		break;
-	}
-
-	return NB_OK;
-}
-
-static int lib_interface_isis_multi_topology_ipv4_unicast_modify(
-	enum nb_event event, const struct lyd_node *dnode,
-	union nb_resource *resource)
-{
-	return lib_interface_isis_multi_topology_common(event, dnode,
-							ISIS_MT_IPV4_UNICAST);
-}
-
-/*
- * XPath:
- * /frr-interface:lib/interface/frr-isisd:isis/multi-topology/ipv4-multicast
- */
-static int lib_interface_isis_multi_topology_ipv4_multicast_modify(
-	enum nb_event event, const struct lyd_node *dnode,
-	union nb_resource *resource)
-{
-	return lib_interface_isis_multi_topology_common(event, dnode,
-							ISIS_MT_IPV4_MULTICAST);
-}
-
-/*
- * XPath:
- * /frr-interface:lib/interface/frr-isisd:isis/multi-topology/ipv4-management
- */
-static int lib_interface_isis_multi_topology_ipv4_management_modify(
-	enum nb_event event, const struct lyd_node *dnode,
-	union nb_resource *resource)
-{
-	return lib_interface_isis_multi_topology_common(event, dnode,
-							ISIS_MT_IPV4_MGMT);
-}
-
-/*
- * XPath:
- * /frr-interface:lib/interface/frr-isisd:isis/multi-topology/ipv6-unicast
- */
-static int lib_interface_isis_multi_topology_ipv6_unicast_modify(
-	enum nb_event event, const struct lyd_node *dnode,
-	union nb_resource *resource)
-{
-	return lib_interface_isis_multi_topology_common(event, dnode,
-							ISIS_MT_IPV6_UNICAST);
-}
-
-/*
- * XPath:
- * /frr-interface:lib/interface/frr-isisd:isis/multi-topology/ipv6-multicast
- */
-static int lib_interface_isis_multi_topology_ipv6_multicast_modify(
-	enum nb_event event, const struct lyd_node *dnode,
-	union nb_resource *resource)
-{
-	return lib_interface_isis_multi_topology_common(event, dnode,
-							ISIS_MT_IPV6_MULTICAST);
-}
-
-/*
- * XPath:
- * /frr-interface:lib/interface/frr-isisd:isis/multi-topology/ipv6-management
- */
-static int lib_interface_isis_multi_topology_ipv6_management_modify(
-	enum nb_event event, const struct lyd_node *dnode,
-	union nb_resource *resource)
-{
-	return lib_interface_isis_multi_topology_common(event, dnode,
-							ISIS_MT_IPV6_MGMT);
-}
-
-/*
- * XPath: /frr-interface:lib/interface/frr-isisd:isis/multi-topology/ipv6-dstsrc
- */
-static int lib_interface_isis_multi_topology_ipv6_dstsrc_modify(
-	enum nb_event event, const struct lyd_node *dnode,
-	union nb_resource *resource)
-{
-	return lib_interface_isis_multi_topology_common(event, dnode,
-							ISIS_MT_IPV6_DSTSRC);
-}
-
-/*
- * XPath: /frr-interface:lib/interface/frr-isisd:isis/adjacencies/adjacency
- */
-static const void *
-lib_interface_isis_adjacencies_adjacency_get_next(const void *parent_list_entry,
-						  const void *list_entry)
-{
-	struct interface *ifp;
-	struct isis_circuit *circuit;
-	struct isis_adjacency *adj, *adj_next = NULL;
-	struct list *list;
-	struct listnode *node, *node_next;
-
-	/* Get first adjacency. */
-	if (list_entry == NULL) {
-		ifp = (struct interface *)parent_list_entry;
-		if (!ifp)
-			return NULL;
-
-		circuit = circuit_scan_by_ifp(ifp);
-		if (!circuit)
-			return NULL;
-
-		switch (circuit->circ_type) {
-		case CIRCUIT_T_BROADCAST:
-			for (int level = ISIS_LEVEL1; level <= ISIS_LEVELS;
-			     level++) {
-				adj = listnode_head(
-					circuit->u.bc.adjdb[level - 1]);
-				if (adj)
-					break;
-			}
-			break;
-		case CIRCUIT_T_P2P:
-			adj = circuit->u.p2p.neighbor;
-			break;
-		default:
-			adj = NULL;
-			break;
-		}
-
-		return adj;
-	}
-
-	/* Get next adjacency. */
-	adj = (struct isis_adjacency *)list_entry;
-	circuit = adj->circuit;
-	switch (circuit->circ_type) {
-	case CIRCUIT_T_BROADCAST:
-		list = circuit->u.bc.adjdb[adj->level - 1];
-		node = listnode_lookup(list, adj);
-		node_next = listnextnode(node);
-		if (node_next)
-			adj_next = listgetdata(node_next);
-		else if (adj->level == ISIS_LEVEL1) {
-			/*
-			 * Once we finish the L1 adjacencies, move to the L2
-			 * adjacencies list.
-			 */
-			list = circuit->u.bc.adjdb[ISIS_LEVEL2 - 1];
-			adj_next = listnode_head(list);
-		}
-		break;
-	case CIRCUIT_T_P2P:
-		/* P2P circuits have at most one adjacency. */
-	default:
-		break;
-	}
-
-	return adj_next;
-}
-
-/*
- * XPath:
- * /frr-interface:lib/interface/frr-isisd:isis/adjacencies/adjacency/neighbor-sys-type
- */
-static struct yang_data *
-lib_interface_isis_adjacencies_adjacency_neighbor_sys_type_get_elem(
-	const char *xpath, const void *list_entry)
-{
-	const struct isis_adjacency *adj = list_entry;
-
-	return yang_data_new_enum(xpath, adj->level);
-}
-
-/*
- * XPath:
- * /frr-interface:lib/interface/frr-isisd:isis/adjacencies/adjacency/neighbor-sysid
- */
-static struct yang_data *
-lib_interface_isis_adjacencies_adjacency_neighbor_sysid_get_elem(
-	const char *xpath, const void *list_entry)
-{
-	const struct isis_adjacency *adj = list_entry;
-
-	return yang_data_new_string(xpath, sysid_print(adj->sysid));
-}
-
-/*
- * XPath:
- * /frr-interface:lib/interface/frr-isisd:isis/adjacencies/adjacency/neighbor-extended-circuit-id
- */
-static struct yang_data *
-lib_interface_isis_adjacencies_adjacency_neighbor_extended_circuit_id_get_elem(
-	const char *xpath, const void *list_entry)
-{
-	const struct isis_adjacency *adj = list_entry;
-
-	return yang_data_new_uint32(xpath, adj->circuit->circuit_id);
-}
-
-/*
- * XPath:
- * /frr-interface:lib/interface/frr-isisd:isis/adjacencies/adjacency/neighbor-snpa
- */
-static struct yang_data *
-lib_interface_isis_adjacencies_adjacency_neighbor_snpa_get_elem(
-	const char *xpath, const void *list_entry)
-{
-	const struct isis_adjacency *adj = list_entry;
-
-	return yang_data_new_string(xpath, snpa_print(adj->snpa));
-}
-
-/*
- * XPath:
- * /frr-interface:lib/interface/frr-isisd:isis/adjacencies/adjacency/hold-timer
- */
-static struct yang_data *
-lib_interface_isis_adjacencies_adjacency_hold_timer_get_elem(
-	const char *xpath, const void *list_entry)
-{
-	const struct isis_adjacency *adj = list_entry;
-
-	return yang_data_new_uint16(xpath, adj->hold_time);
-}
-
-/*
- * XPath:
- * /frr-interface:lib/interface/frr-isisd:isis/adjacencies/adjacency/neighbor-priority
- */
-static struct yang_data *
-lib_interface_isis_adjacencies_adjacency_neighbor_priority_get_elem(
-	const char *xpath, const void *list_entry)
-{
-	const struct isis_adjacency *adj = list_entry;
-
-	return yang_data_new_uint8(xpath, adj->prio[adj->level - 1]);
-}
-
-/*
- * XPath:
- * /frr-interface:lib/interface/frr-isisd:isis/adjacencies/adjacency/state
- */
-static struct yang_data *
-lib_interface_isis_adjacencies_adjacency_state_get_elem(const char *xpath,
-							const void *list_entry)
-{
-	const struct isis_adjacency *adj = list_entry;
-
-	return yang_data_new_string(xpath, isis_yang_adj_state(adj->adj_state));
-}
-
-/*
- * XPath:
- * /frr-interface:lib/interface/frr-isisd:isis/event-counters/adjacency-changes
- */
-static struct yang_data *
-lib_interface_isis_event_counters_adjacency_changes_get_elem(
-	const char *xpath, const void *list_entry)
-{
-	struct interface *ifp;
-	struct isis_circuit *circuit;
-
-	ifp = (struct interface *)list_entry;
-	if (!ifp)
-		return NULL;
-
-	circuit = circuit_scan_by_ifp(ifp);
-	if (!circuit)
-		return NULL;
-
-	return yang_data_new_uint32(xpath, circuit->adj_state_changes);
-}
-
-/*
- * XPath:
- * /frr-interface:lib/interface/frr-isisd:isis/event-counters/adjacency-number
- */
-static struct yang_data *
-lib_interface_isis_event_counters_adjacency_number_get_elem(
-	const char *xpath, const void *list_entry)
-{
-	struct interface *ifp;
-	struct isis_circuit *circuit;
-	struct isis_adjacency *adj;
-	struct listnode *node;
-	uint32_t total = 0;
-
-	ifp = (struct interface *)list_entry;
-	if (!ifp)
-		return NULL;
-
-	circuit = circuit_scan_by_ifp(ifp);
-	if (!circuit)
-		return NULL;
-
-	/*
-	 * TODO: keep track of the number of adjacencies instead of calculating
-	 * it on demand.
-	 */
-	switch (circuit->circ_type) {
-	case CIRCUIT_T_BROADCAST:
-		for (int level = ISIS_LEVEL1; level <= ISIS_LEVELS; level++) {
-			for (ALL_LIST_ELEMENTS_RO(
-				     circuit->u.bc.adjdb[level - 1], node, adj))
-				total++;
-		}
-		break;
-	case CIRCUIT_T_P2P:
-		adj = circuit->u.p2p.neighbor;
-		if (adj)
-			total = 1;
-		break;
-	default:
-		break;
-	}
-
-	return yang_data_new_uint32(xpath, total);
-}
-
-/*
- * XPath: /frr-interface:lib/interface/frr-isisd:isis/event-counters/init-fails
- */
-static struct yang_data *
-lib_interface_isis_event_counters_init_fails_get_elem(const char *xpath,
-						      const void *list_entry)
-{
-	struct interface *ifp;
-	struct isis_circuit *circuit;
-
-	ifp = (struct interface *)list_entry;
-	if (!ifp)
-		return NULL;
-
-	circuit = circuit_scan_by_ifp(ifp);
-	if (!circuit)
-		return NULL;
-
-	return yang_data_new_uint32(xpath, circuit->init_failures);
-}
-
-/*
- * XPath:
- * /frr-interface:lib/interface/frr-isisd:isis/event-counters/adjacency-rejects
- */
-static struct yang_data *
-lib_interface_isis_event_counters_adjacency_rejects_get_elem(
-	const char *xpath, const void *list_entry)
-{
-	struct interface *ifp;
-	struct isis_circuit *circuit;
-
-	ifp = (struct interface *)list_entry;
-	if (!ifp)
-		return NULL;
-
-	circuit = circuit_scan_by_ifp(ifp);
-	if (!circuit)
-		return NULL;
-
-	return yang_data_new_uint32(xpath, circuit->rej_adjacencies);
-}
-
-/*
- * XPath:
- * /frr-interface:lib/interface/frr-isisd:isis/event-counters/id-len-mismatch
- */
-static struct yang_data *
-lib_interface_isis_event_counters_id_len_mismatch_get_elem(
-	const char *xpath, const void *list_entry)
-{
-	struct interface *ifp;
-	struct isis_circuit *circuit;
-
-	ifp = (struct interface *)list_entry;
-	if (!ifp)
-		return NULL;
-
-	circuit = circuit_scan_by_ifp(ifp);
-	if (!circuit)
-		return NULL;
-
-	return yang_data_new_uint32(xpath, circuit->id_len_mismatches);
-}
-
-/*
- * XPath:
- * /frr-interface:lib/interface/frr-isisd:isis/event-counters/max-area-addresses-mismatch
- */
-static struct yang_data *
-lib_interface_isis_event_counters_max_area_addresses_mismatch_get_elem(
-	const char *xpath, const void *list_entry)
-{
-	struct interface *ifp;
-	struct isis_circuit *circuit;
-
-	ifp = (struct interface *)list_entry;
-	if (!ifp)
-		return NULL;
-
-	circuit = circuit_scan_by_ifp(ifp);
-	if (!circuit)
-		return NULL;
-
-	return yang_data_new_uint32(xpath, circuit->max_area_addr_mismatches);
-}
-
-/*
- * XPath:
- * /frr-interface:lib/interface/frr-isisd:isis/event-counters/authentication-type-fails
- */
-static struct yang_data *
-lib_interface_isis_event_counters_authentication_type_fails_get_elem(
-	const char *xpath, const void *list_entry)
-{
-	struct interface *ifp;
-	struct isis_circuit *circuit;
-
-	ifp = (struct interface *)list_entry;
-	if (!ifp)
-		return NULL;
-
-	circuit = circuit_scan_by_ifp(ifp);
-	if (!circuit)
-		return NULL;
-
-	return yang_data_new_uint32(xpath, circuit->auth_type_failures);
-}
-
-/*
- * XPath:
- * /frr-interface:lib/interface/frr-isisd:isis/event-counters/authentication-fails
- */
-static struct yang_data *
-lib_interface_isis_event_counters_authentication_fails_get_elem(
-	const char *xpath, const void *list_entry)
-{
-	struct interface *ifp;
-	struct isis_circuit *circuit;
-
-	ifp = (struct interface *)list_entry;
-	if (!ifp)
-		return NULL;
-
-	circuit = circuit_scan_by_ifp(ifp);
-	if (!circuit)
-		return NULL;
-
-	return yang_data_new_uint32(xpath, circuit->auth_failures);
-}
-
-/*
- * NOTIFICATIONS
- */
-static void notif_prep_instance_hdr(const char *xpath,
-				    const struct isis_area *area,
-				    const char *routing_instance,
-				    struct list *args)
-{
-	char xpath_arg[XPATH_MAXLEN];
-	struct yang_data *data;
-
-	snprintf(xpath_arg, sizeof(xpath_arg), "%s/routing-instance", xpath);
-	data = yang_data_new_string(xpath_arg, routing_instance);
-	listnode_add(args, data);
-	snprintf(xpath_arg, sizeof(xpath_arg), "%s/routing-protocol-name",
-		 xpath);
-	data = yang_data_new_string(xpath_arg, area->area_tag);
-	listnode_add(args, data);
-	snprintf(xpath_arg, sizeof(xpath_arg), "%s/isis-level", xpath);
-	data = yang_data_new_enum(xpath_arg, area->is_type);
-	listnode_add(args, data);
-}
-
-static void notif_prepr_iface_hdr(const char *xpath,
-				  const struct isis_circuit *circuit,
-				  struct list *args)
-{
-	char xpath_arg[XPATH_MAXLEN];
-	struct yang_data *data;
-
-	snprintf(xpath_arg, sizeof(xpath_arg), "%s/interface-name", xpath);
-	data = yang_data_new_string(xpath_arg, circuit->interface->name);
-	listnode_add(args, data);
-	snprintf(xpath_arg, sizeof(xpath_arg), "%s/interface-level", xpath);
-	data = yang_data_new_enum(xpath_arg, circuit->is_type);
-	listnode_add(args, data);
-	snprintf(xpath_arg, sizeof(xpath_arg), "%s/extended-circuit-id", xpath);
-	/* we do not seem to have the extended version of the circuit_id */
-	data = yang_data_new_uint32(xpath_arg, (uint32_t)circuit->circuit_id);
-	listnode_add(args, data);
-}
-
-/*
- * XPath:
- * /frr-isisd:database-overload
- */
-void isis_notif_db_overload(const struct isis_area *area, bool overload)
-{
-	const char *xpath = "/frr-isisd:database-overload";
-	struct list *arguments = yang_data_list_new();
-	char xpath_arg[XPATH_MAXLEN];
-	struct yang_data *data;
-
-	notif_prep_instance_hdr(xpath, area, "default", arguments);
-	snprintf(xpath_arg, sizeof(xpath_arg), "%s/overload", xpath);
-	data = yang_data_new_enum(xpath_arg, !!overload);
-	listnode_add(arguments, data);
-
-	nb_notification_send(xpath, arguments);
-}
-
-/*
- * XPath:
- * /frr-isisd:lsp-too-large
- */
-void isis_notif_lsp_too_large(const struct isis_circuit *circuit,
-			      uint32_t pdu_size, const char *lsp_id)
-{
-	const char *xpath = "/frr-isisd:lsp-too-large";
-	struct list *arguments = yang_data_list_new();
-	char xpath_arg[XPATH_MAXLEN];
-	struct yang_data *data;
-	struct isis_area *area = circuit->area;
-
-	notif_prep_instance_hdr(xpath, area, "default", arguments);
-	notif_prepr_iface_hdr(xpath, circuit, arguments);
-	snprintf(xpath_arg, sizeof(xpath_arg), "%s/pdu-size", xpath);
-	data = yang_data_new_uint32(xpath_arg, pdu_size);
-	listnode_add(arguments, data);
-	snprintf(xpath_arg, sizeof(xpath_arg), "%s/lsp-id", xpath);
-	data = yang_data_new_string(xpath_arg, lsp_id);
-	listnode_add(arguments, data);
-
-	nb_notification_send(xpath, arguments);
-}
-
-/*
- * XPath:
- * /frr-isisd:if-state-change
- */
-void isis_notif_if_state_change(const struct isis_circuit *circuit, bool down)
-{
-	const char *xpath = "/frr-isisd:if-state-change";
-	struct list *arguments = yang_data_list_new();
-	char xpath_arg[XPATH_MAXLEN];
-	struct yang_data *data;
-	struct isis_area *area = circuit->area;
-
-	notif_prep_instance_hdr(xpath, area, "default", arguments);
-	notif_prepr_iface_hdr(xpath, circuit, arguments);
-	snprintf(xpath_arg, sizeof(xpath_arg), "%s/state", xpath);
-	data = yang_data_new_enum(xpath_arg, !!down);
-	listnode_add(arguments, data);
-
-	nb_notification_send(xpath, arguments);
-}
-
-/*
- * XPath:
- * /frr-isisd:corrupted-lsp-detected
- */
-void isis_notif_corrupted_lsp(const struct isis_area *area, const char *lsp_id)
-{
-	const char *xpath = "/frr-isisd:corrupted-lsp-detected";
-	struct list *arguments = yang_data_list_new();
-	char xpath_arg[XPATH_MAXLEN];
-	struct yang_data *data;
-
-	notif_prep_instance_hdr(xpath, area, "default", arguments);
-	snprintf(xpath_arg, sizeof(xpath_arg), "%s/lsp-id", xpath);
-	data = yang_data_new_string(xpath_arg, lsp_id);
-	listnode_add(arguments, data);
-
-	nb_notification_send(xpath, arguments);
-}
-
-/*
- * XPath:
- * /frr-isisd:attempt-to-exceed-max-sequence
- */
-void isis_notif_lsp_exceed_max(const struct isis_area *area, const char *lsp_id)
-{
-	const char *xpath = "/frr-isisd:attempt-to-exceed-max-sequence";
-	struct list *arguments = yang_data_list_new();
-	char xpath_arg[XPATH_MAXLEN];
-	struct yang_data *data;
-
-	notif_prep_instance_hdr(xpath, area, "default", arguments);
-	snprintf(xpath_arg, sizeof(xpath_arg), "%s/lsp-id", xpath);
-	data = yang_data_new_string(xpath_arg, lsp_id);
-	listnode_add(arguments, data);
-
-	nb_notification_send(xpath, arguments);
-}
-
-/*
- * XPath:
- * /frr-isisd:max-area-addresses-mismatch
- */
-void isis_notif_max_area_addr_mismatch(const struct isis_circuit *circuit,
-				       uint8_t max_area_addrs,
-				       const char *raw_pdu)
-{
-	const char *xpath = "/frr-isisd:max-area-addresses-mismatch";
-	struct list *arguments = yang_data_list_new();
-	char xpath_arg[XPATH_MAXLEN];
-	struct yang_data *data;
-	struct isis_area *area = circuit->area;
-
-	notif_prep_instance_hdr(xpath, area, "default", arguments);
-	notif_prepr_iface_hdr(xpath, circuit, arguments);
-	snprintf(xpath_arg, sizeof(xpath_arg), "%s/max-area-addresses", xpath);
-	data = yang_data_new_uint8(xpath_arg, max_area_addrs);
-	listnode_add(arguments, data);
-	snprintf(xpath_arg, sizeof(xpath_arg), "%s/raw-pdu", xpath);
-	data = yang_data_new(xpath_arg, raw_pdu);
-	listnode_add(arguments, data);
-
-	nb_notification_send(xpath, arguments);
-}
-
-/*
- * XPath:
- * /frr-isisd:authentication-type-failure
- */
-void isis_notif_authentication_type_failure(const struct isis_circuit *circuit,
-					    const char *raw_pdu)
-{
-	const char *xpath = "/frr-isisd:authentication-type-failure";
-	struct list *arguments = yang_data_list_new();
-	char xpath_arg[XPATH_MAXLEN];
-	struct yang_data *data;
-	struct isis_area *area = circuit->area;
-
-	notif_prep_instance_hdr(xpath, area, "default", arguments);
-	notif_prepr_iface_hdr(xpath, circuit, arguments);
-	snprintf(xpath_arg, sizeof(xpath_arg), "%s/raw-pdu", xpath);
-	data = yang_data_new(xpath_arg, raw_pdu);
-	listnode_add(arguments, data);
-
-	nb_notification_send(xpath, arguments);
-}
-
-/*
- * XPath:
- * /frr-isisd:authentication-failure
- */
-void isis_notif_authentication_failure(const struct isis_circuit *circuit,
-				       const char *raw_pdu)
-{
-	const char *xpath = "/frr-isisd:authentication-failure";
-	struct list *arguments = yang_data_list_new();
-	char xpath_arg[XPATH_MAXLEN];
-	struct yang_data *data;
-	struct isis_area *area = circuit->area;
-
-	notif_prep_instance_hdr(xpath, area, "default", arguments);
-	notif_prepr_iface_hdr(xpath, circuit, arguments);
-	snprintf(xpath_arg, sizeof(xpath_arg), "%s/raw-pdu", xpath);
-	data = yang_data_new(xpath_arg, raw_pdu);
-	listnode_add(arguments, data);
-
-	nb_notification_send(xpath, arguments);
-}
-
-/*
- * XPath:
- * /frr-isisd:adjacency-state-change
- */
-void isis_notif_adj_state_change(const struct isis_adjacency *adj,
-				 int new_state, const char *reason)
-{
-	const char *xpath = "/frr-isisd:adjacency-state-change";
-	struct list *arguments = yang_data_list_new();
-	char xpath_arg[XPATH_MAXLEN];
-	struct yang_data *data;
-	struct isis_circuit *circuit = adj->circuit;
-	struct isis_area *area = circuit->area;
-	struct isis_dynhn *dyn = dynhn_find_by_id(adj->sysid);
-
-	notif_prep_instance_hdr(xpath, area, "default", arguments);
-	notif_prepr_iface_hdr(xpath, circuit, arguments);
-	if (dyn) {
-		snprintf(xpath_arg, sizeof(xpath_arg), "%s/neighbor", xpath);
-		data = yang_data_new_string(xpath_arg, dyn->hostname);
-		listnode_add(arguments, data);
-	}
-	snprintf(xpath_arg, sizeof(xpath_arg), "%s/neighbor-system-id", xpath);
-	data = yang_data_new_string(xpath_arg, sysid_print(adj->sysid));
-	listnode_add(arguments, data);
-
-	snprintf(xpath_arg, sizeof(xpath_arg), "%s/state", xpath);
-	data = yang_data_new_string(xpath_arg, isis_yang_adj_state(new_state));
-	listnode_add(arguments, data);
-	if (new_state == ISIS_ADJ_DOWN) {
-		snprintf(xpath_arg, sizeof(xpath_arg), "%s/reason", xpath);
-		data = yang_data_new_string(xpath_arg, reason);
-		listnode_add(arguments, data);
-	}
-
-	nb_notification_send(xpath, arguments);
-}
-
-/*
- * XPath:
- * /frr-isisd:rejected-adjacency
- */
-void isis_notif_reject_adjacency(const struct isis_circuit *circuit,
-				 const char *reason, const char *raw_pdu)
-{
-	const char *xpath = "/frr-isisd:rejected-adjacency";
-	struct list *arguments = yang_data_list_new();
-	char xpath_arg[XPATH_MAXLEN];
-	struct yang_data *data;
-	struct isis_area *area = circuit->area;
-
-	notif_prep_instance_hdr(xpath, area, "default", arguments);
-	notif_prepr_iface_hdr(xpath, circuit, arguments);
-	snprintf(xpath_arg, sizeof(xpath_arg), "%s/reason", xpath);
-	data = yang_data_new_string(xpath_arg, reason);
-	listnode_add(arguments, data);
-	snprintf(xpath_arg, sizeof(xpath_arg), "%s/raw-pdu", xpath);
-	data = yang_data_new(xpath_arg, raw_pdu);
-	listnode_add(arguments, data);
-
-	nb_notification_send(xpath, arguments);
-}
-
-/*
- * XPath:
- * /frr-isisd:area-mismatch
- */
-void isis_notif_area_mismatch(const struct isis_circuit *circuit,
-			      const char *raw_pdu)
-{
-	const char *xpath = "/frr-isisd:area-mismatch";
-	struct list *arguments = yang_data_list_new();
-	char xpath_arg[XPATH_MAXLEN];
-	struct yang_data *data;
-	struct isis_area *area = circuit->area;
-
-	notif_prep_instance_hdr(xpath, area, "default", arguments);
-	notif_prepr_iface_hdr(xpath, circuit, arguments);
-	snprintf(xpath_arg, sizeof(xpath_arg), "%s/raw-pdu", xpath);
-	data = yang_data_new(xpath_arg, raw_pdu);
-	listnode_add(arguments, data);
-
-	nb_notification_send(xpath, arguments);
-}
-
-/*
- * XPath:
- * /frr-isisd:lsp-received
- */
-void isis_notif_lsp_received(const struct isis_circuit *circuit,
-			     const char *lsp_id, uint32_t seqno,
-			     uint32_t timestamp, const char *sys_id)
-{
-	const char *xpath = "/frr-isisd:lsp-received";
-	struct list *arguments = yang_data_list_new();
-	char xpath_arg[XPATH_MAXLEN];
-	struct yang_data *data;
-	struct isis_area *area = circuit->area;
-
-	notif_prep_instance_hdr(xpath, area, "default", arguments);
-	notif_prepr_iface_hdr(xpath, circuit, arguments);
-	snprintf(xpath_arg, sizeof(xpath_arg), "%s/lsp-id", xpath);
-	data = yang_data_new_string(xpath_arg, lsp_id);
-	listnode_add(arguments, data);
-	snprintf(xpath_arg, sizeof(xpath_arg), "%s/sequence", xpath);
-	data = yang_data_new_uint32(xpath_arg, seqno);
-	listnode_add(arguments, data);
-	snprintf(xpath_arg, sizeof(xpath_arg), "%s/received-timestamp", xpath);
-	data = yang_data_new_uint32(xpath_arg, timestamp);
-	listnode_add(arguments, data);
-	snprintf(xpath_arg, sizeof(xpath_arg), "%s/neighbor-system-id", xpath);
-	data = yang_data_new_string(xpath_arg, sys_id);
-	listnode_add(arguments, data);
-
-	nb_notification_send(xpath, arguments);
-}
-
-/*
- * XPath:
- * /frr-isisd:lsp-generation
- */
-void isis_notif_lsp_gen(const struct isis_area *area, const char *lsp_id,
-			uint32_t seqno, uint32_t timestamp)
-{
-	const char *xpath = "/frr-isisd:lsp-generation";
-	struct list *arguments = yang_data_list_new();
-	char xpath_arg[XPATH_MAXLEN];
-	struct yang_data *data;
-
-	notif_prep_instance_hdr(xpath, area, "default", arguments);
-	snprintf(xpath_arg, sizeof(xpath_arg), "%s/lsp-id", xpath);
-	data = yang_data_new_string(xpath_arg, lsp_id);
-	listnode_add(arguments, data);
-	snprintf(xpath_arg, sizeof(xpath_arg), "%s/sequence", xpath);
-	data = yang_data_new_uint32(xpath_arg, seqno);
-	listnode_add(arguments, data);
-	snprintf(xpath_arg, sizeof(xpath_arg), "%s/send-timestamp", xpath);
-	data = yang_data_new_uint32(xpath_arg, timestamp);
-	listnode_add(arguments, data);
-
-	nb_notification_send(xpath, arguments);
-}
-
-/*
- * XPath:
- * /frr-isisd:id-len-mismatch
- */
-void isis_notif_id_len_mismatch(const struct isis_circuit *circuit,
-				uint8_t rcv_id_len, const char *raw_pdu)
-{
-	const char *xpath = "/frr-isisd:id-len-mismatch";
-	struct list *arguments = yang_data_list_new();
-	char xpath_arg[XPATH_MAXLEN];
-	struct yang_data *data;
-	struct isis_area *area = circuit->area;
-
-	notif_prep_instance_hdr(xpath, area, "default", arguments);
-	notif_prepr_iface_hdr(xpath, circuit, arguments);
-	snprintf(xpath_arg, sizeof(xpath_arg), "%s/pdu-field-len", xpath);
-	data = yang_data_new_uint8(xpath_arg, rcv_id_len);
-	listnode_add(arguments, data);
-	snprintf(xpath_arg, sizeof(xpath_arg), "%s/raw-pdu", xpath);
-	data = yang_data_new(xpath_arg, raw_pdu);
-	listnode_add(arguments, data);
-
-	nb_notification_send(xpath, arguments);
-}
-
-/*
- * XPath:
- * /frr-isisd:version-skew
- */
-void isis_notif_version_skew(const struct isis_circuit *circuit,
-			     uint8_t version, const char *raw_pdu)
-{
-	const char *xpath = "/frr-isisd:version-skew";
-	struct list *arguments = yang_data_list_new();
-	char xpath_arg[XPATH_MAXLEN];
-	struct yang_data *data;
-	struct isis_area *area = circuit->area;
-
-	notif_prep_instance_hdr(xpath, area, "default", arguments);
-	notif_prepr_iface_hdr(xpath, circuit, arguments);
-	snprintf(xpath_arg, sizeof(xpath_arg), "%s/protocol-version", xpath);
-	data = yang_data_new_uint8(xpath_arg, version);
-	listnode_add(arguments, data);
-	snprintf(xpath_arg, sizeof(xpath_arg), "%s/raw-pdu", xpath);
-	data = yang_data_new(xpath_arg, raw_pdu);
-	listnode_add(arguments, data);
-
-	nb_notification_send(xpath, arguments);
-}
-
-/*
- * XPath:
- * /frr-isisd:lsp-error-detected
- */
-void isis_notif_lsp_error(const struct isis_circuit *circuit,
-			  const char *lsp_id, const char *raw_pdu,
-			  __attribute__((unused)) uint32_t offset,
-			  __attribute__((unused)) uint8_t tlv_type)
-{
-	const char *xpath = "/frr-isisd:lsp-error-detected";
-	struct list *arguments = yang_data_list_new();
-	char xpath_arg[XPATH_MAXLEN];
-	struct yang_data *data;
-	struct isis_area *area = circuit->area;
-
-	notif_prep_instance_hdr(xpath, area, "default", arguments);
-	notif_prepr_iface_hdr(xpath, circuit, arguments);
-	snprintf(xpath_arg, sizeof(xpath_arg), "%s/lsp-id", xpath);
-	data = yang_data_new_string(xpath_arg, lsp_id);
-	listnode_add(arguments, data);
-	snprintf(xpath_arg, sizeof(xpath_arg), "%s/raw-pdu", xpath);
-	data = yang_data_new(xpath_arg, raw_pdu);
-	listnode_add(arguments, data);
-	/* ignore offset and tlv_type which cannot be set properly */
-
-	nb_notification_send(xpath, arguments);
-}
-
-/*
- * XPath:
- * /frr-isisd:sequence-number-skipped
- */
-void isis_notif_seqno_skipped(const struct isis_circuit *circuit,
-			      const char *lsp_id)
-{
-	const char *xpath = "/frr-isisd:sequence-number-skipped";
-	struct list *arguments = yang_data_list_new();
-	char xpath_arg[XPATH_MAXLEN];
-	struct yang_data *data;
-	struct isis_area *area = circuit->area;
-
-	notif_prep_instance_hdr(xpath, area, "default", arguments);
-	notif_prepr_iface_hdr(xpath, circuit, arguments);
-	snprintf(xpath_arg, sizeof(xpath_arg), "%s/lsp-id", xpath);
-	data = yang_data_new_string(xpath_arg, lsp_id);
-	listnode_add(arguments, data);
-
-	nb_notification_send(xpath, arguments);
-}
-
-/*
- * XPath:
- * /frr-isisd:own-lsp-purge
- */
-void isis_notif_own_lsp_purge(const struct isis_circuit *circuit,
-			      const char *lsp_id)
-{
-	const char *xpath = "/frr-isisd:own-lsp-purge";
-	struct list *arguments = yang_data_list_new();
-	char xpath_arg[XPATH_MAXLEN];
-	struct yang_data *data;
-	struct isis_area *area = circuit->area;
-
-	notif_prep_instance_hdr(xpath, area, "default", arguments);
-	notif_prepr_iface_hdr(xpath, circuit, arguments);
-	snprintf(xpath_arg, sizeof(xpath_arg), "%s/lsp-id", xpath);
-	data = yang_data_new_string(xpath_arg, lsp_id);
-	listnode_add(arguments, data);
-
-	nb_notification_send(xpath, arguments);
-}
-
-/* clang-format off */
-const struct frr_yang_module_info frr_isisd_info = {
-	.name = "frr-isisd",
-	.nodes = {
-		{
-			.xpath = "/frr-isisd:isis/instance",
-			.cbs = {
-				.cli_show = cli_show_router_isis,
-				.create = isis_instance_create,
-				.destroy = isis_instance_destroy,
-			},
-			.priority = NB_DFLT_PRIORITY - 1,
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/is-type",
-			.cbs = {
-				.cli_show = cli_show_isis_is_type,
-				.modify = isis_instance_is_type_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/area-address",
-			.cbs = {
-				.cli_show = cli_show_isis_area_address,
-				.create = isis_instance_area_address_create,
-				.destroy = isis_instance_area_address_destroy,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/dynamic-hostname",
-			.cbs = {
-				.cli_show = cli_show_isis_dynamic_hostname,
-				.modify = isis_instance_dynamic_hostname_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/attached",
-			.cbs = {
-				.cli_show = cli_show_isis_attached,
-				.modify = isis_instance_attached_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/overload",
-			.cbs = {
-				.cli_show = cli_show_isis_overload,
-				.modify = isis_instance_overload_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/metric-style",
-			.cbs = {
-				.cli_show = cli_show_isis_metric_style,
-				.modify = isis_instance_metric_style_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/purge-originator",
-			.cbs = {
-				.cli_show = cli_show_isis_purge_origin,
-				.modify = isis_instance_purge_originator_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/lsp/mtu",
-			.cbs = {
-				.cli_show = cli_show_isis_lsp_mtu,
-				.modify = isis_instance_lsp_mtu_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/lsp/refresh-interval",
-			.cbs = {
-				.cli_show = cli_show_isis_lsp_ref_interval,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/lsp/refresh-interval/level-1",
-			.cbs = {
-				.modify = isis_instance_lsp_refresh_interval_level_1_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/lsp/refresh-interval/level-2",
-			.cbs = {
-				.modify = isis_instance_lsp_refresh_interval_level_2_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/lsp/maximum-lifetime",
-			.cbs = {
-				.cli_show = cli_show_isis_lsp_max_lifetime,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/lsp/maximum-lifetime/level-1",
-			.cbs = {
-				.modify = isis_instance_lsp_maximum_lifetime_level_1_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/lsp/maximum-lifetime/level-2",
-			.cbs = {
-				.modify = isis_instance_lsp_maximum_lifetime_level_2_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/lsp/generation-interval",
-			.cbs = {
-				.cli_show = cli_show_isis_lsp_gen_interval,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/lsp/generation-interval/level-1",
-			.cbs = {
-				.modify = isis_instance_lsp_generation_interval_level_1_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/lsp/generation-interval/level-2",
-			.cbs = {
-				.modify = isis_instance_lsp_generation_interval_level_2_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/spf/ietf-backoff-delay",
-			.cbs = {
-				.apply_finish = ietf_backoff_delay_apply_finish,
-				.cli_show = cli_show_isis_spf_ietf_backoff,
-				.create = isis_instance_spf_ietf_backoff_delay_create,
-				.destroy = isis_instance_spf_ietf_backoff_delay_destroy,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/spf/ietf-backoff-delay/init-delay",
-			.cbs = {
-				.modify = isis_instance_spf_ietf_backoff_delay_init_delay_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/spf/ietf-backoff-delay/short-delay",
-			.cbs = {
-				.modify = isis_instance_spf_ietf_backoff_delay_short_delay_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/spf/ietf-backoff-delay/long-delay",
-			.cbs = {
-				.modify = isis_instance_spf_ietf_backoff_delay_long_delay_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/spf/ietf-backoff-delay/hold-down",
-			.cbs = {
-				.modify = isis_instance_spf_ietf_backoff_delay_hold_down_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/spf/ietf-backoff-delay/time-to-learn",
-			.cbs = {
-				.modify = isis_instance_spf_ietf_backoff_delay_time_to_learn_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/spf/minimum-interval",
-			.cbs = {
-				.cli_show = cli_show_isis_spf_min_interval,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/spf/minimum-interval/level-1",
-			.cbs = {
-				.modify = isis_instance_spf_minimum_interval_level_1_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/spf/minimum-interval/level-2",
-			.cbs = {
-				.modify = isis_instance_spf_minimum_interval_level_2_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/area-password",
-			.cbs = {
-				.apply_finish = area_password_apply_finish,
-				.cli_show = cli_show_isis_area_pwd,
-				.create = isis_instance_area_password_create,
-				.destroy = isis_instance_area_password_destroy,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/area-password/password",
-			.cbs = {
-				.modify = isis_instance_area_password_password_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/area-password/password-type",
-			.cbs = {
-				.modify = isis_instance_area_password_password_type_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/area-password/authenticate-snp",
-			.cbs = {
-				.modify = isis_instance_area_password_authenticate_snp_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/domain-password",
-			.cbs = {
-				.apply_finish = domain_password_apply_finish,
-				.cli_show = cli_show_isis_domain_pwd,
-				.create = isis_instance_domain_password_create,
-				.destroy = isis_instance_domain_password_destroy,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/domain-password/password",
-			.cbs = {
-				.modify = isis_instance_domain_password_password_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/domain-password/password-type",
-			.cbs = {
-				.modify = isis_instance_domain_password_password_type_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/domain-password/authenticate-snp",
-			.cbs = {
-				.modify = isis_instance_domain_password_authenticate_snp_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/default-information-originate/ipv4",
-			.cbs = {
-				.apply_finish = default_info_origin_ipv4_apply_finish,
-				.cli_show = cli_show_isis_def_origin_ipv4,
-				.create = isis_instance_default_information_originate_ipv4_create,
-				.destroy = isis_instance_default_information_originate_ipv4_destroy,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/default-information-originate/ipv4/always",
-			.cbs = {
-				.modify = isis_instance_default_information_originate_ipv4_always_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/default-information-originate/ipv4/route-map",
-			.cbs = {
-				.destroy = isis_instance_default_information_originate_ipv4_route_map_destroy,
-				.modify = isis_instance_default_information_originate_ipv4_route_map_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/default-information-originate/ipv4/metric",
-			.cbs = {
-				.modify = isis_instance_default_information_originate_ipv4_metric_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/default-information-originate/ipv6",
-			.cbs = {
-				.apply_finish = default_info_origin_ipv6_apply_finish,
-				.cli_show = cli_show_isis_def_origin_ipv6,
-				.create = isis_instance_default_information_originate_ipv6_create,
-				.destroy = isis_instance_default_information_originate_ipv6_destroy,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/default-information-originate/ipv6/always",
-			.cbs = {
-				.modify = isis_instance_default_information_originate_ipv6_always_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/default-information-originate/ipv6/route-map",
-			.cbs = {
-				.destroy = isis_instance_default_information_originate_ipv6_route_map_destroy,
-				.modify = isis_instance_default_information_originate_ipv6_route_map_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/default-information-originate/ipv6/metric",
-			.cbs = {
-				.modify = isis_instance_default_information_originate_ipv6_metric_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/redistribute/ipv4",
-			.cbs = {
-				.apply_finish = redistribute_ipv4_apply_finish,
-				.cli_show = cli_show_isis_redistribute_ipv4,
-				.create = isis_instance_redistribute_ipv4_create,
-				.destroy = isis_instance_redistribute_ipv4_destroy,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/redistribute/ipv4/route-map",
-			.cbs = {
-				.destroy = isis_instance_redistribute_ipv4_route_map_destroy,
-				.modify = isis_instance_redistribute_ipv4_route_map_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/redistribute/ipv4/metric",
-			.cbs = {
-				.modify = isis_instance_redistribute_ipv4_metric_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/redistribute/ipv6",
-			.cbs = {
-				.apply_finish = redistribute_ipv6_apply_finish,
-				.cli_show = cli_show_isis_redistribute_ipv6,
-				.create = isis_instance_redistribute_ipv6_create,
-				.destroy = isis_instance_redistribute_ipv6_destroy,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/redistribute/ipv6/route-map",
-			.cbs = {
-				.destroy = isis_instance_redistribute_ipv6_route_map_destroy,
-				.modify = isis_instance_redistribute_ipv6_route_map_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/redistribute/ipv6/metric",
-			.cbs = {
-				.modify = isis_instance_redistribute_ipv6_metric_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/multi-topology/ipv4-multicast",
-			.cbs = {
-				.cli_show = cli_show_isis_mt_ipv4_multicast,
-				.create = isis_instance_multi_topology_ipv4_multicast_create,
-				.destroy = isis_instance_multi_topology_ipv4_multicast_destroy,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/multi-topology/ipv4-multicast/overload",
-			.cbs = {
-				.modify = isis_instance_multi_topology_ipv4_multicast_overload_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/multi-topology/ipv4-management",
-			.cbs = {
-				.cli_show = cli_show_isis_mt_ipv4_mgmt,
-				.create = isis_instance_multi_topology_ipv4_management_create,
-				.destroy = isis_instance_multi_topology_ipv4_management_destroy,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/multi-topology/ipv4-management/overload",
-			.cbs = {
-				.modify = isis_instance_multi_topology_ipv4_management_overload_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/multi-topology/ipv6-unicast",
-			.cbs = {
-				.cli_show = cli_show_isis_mt_ipv6_unicast,
-				.create = isis_instance_multi_topology_ipv6_unicast_create,
-				.destroy = isis_instance_multi_topology_ipv6_unicast_destroy,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/multi-topology/ipv6-unicast/overload",
-			.cbs = {
-				.modify = isis_instance_multi_topology_ipv6_unicast_overload_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/multi-topology/ipv6-multicast",
-			.cbs = {
-				.cli_show = cli_show_isis_mt_ipv6_multicast,
-				.create = isis_instance_multi_topology_ipv6_multicast_create,
-				.destroy = isis_instance_multi_topology_ipv6_multicast_destroy,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/multi-topology/ipv6-multicast/overload",
-			.cbs = {
-				.modify = isis_instance_multi_topology_ipv6_multicast_overload_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/multi-topology/ipv6-management",
-			.cbs = {
-				.cli_show = cli_show_isis_mt_ipv6_mgmt,
-				.create = isis_instance_multi_topology_ipv6_management_create,
-				.destroy = isis_instance_multi_topology_ipv6_management_destroy,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/multi-topology/ipv6-management/overload",
-			.cbs = {
-				.modify = isis_instance_multi_topology_ipv6_management_overload_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/multi-topology/ipv6-dstsrc",
-			.cbs = {
-				.cli_show = cli_show_isis_mt_ipv6_dstsrc,
-				.create = isis_instance_multi_topology_ipv6_dstsrc_create,
-				.destroy = isis_instance_multi_topology_ipv6_dstsrc_destroy,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/multi-topology/ipv6-dstsrc/overload",
-			.cbs = {
-				.modify = isis_instance_multi_topology_ipv6_dstsrc_overload_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/log-adjacency-changes",
-			.cbs = {
-				.cli_show = cli_show_isis_log_adjacency,
-				.modify = isis_instance_log_adjacency_changes_modify,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/mpls-te",
-			.cbs = {
-				.cli_show = cli_show_isis_mpls_te,
-				.create = isis_instance_mpls_te_create,
-				.destroy = isis_instance_mpls_te_destroy,
-			},
-		},
-		{
-			.xpath = "/frr-isisd:isis/instance/mpls-te/router-address",
-			.cbs = {
-				.cli_show = cli_show_isis_mpls_te_router_addr,
-				.destroy = isis_instance_mpls_te_router_address_destroy,
-				.modify = isis_instance_mpls_te_router_address_modify,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis",
-			.cbs = {
-				.create = lib_interface_isis_create,
-				.destroy = lib_interface_isis_destroy,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/area-tag",
-			.cbs = {
-				.modify = lib_interface_isis_area_tag_modify,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/circuit-type",
-			.cbs = {
-				.cli_show = cli_show_ip_isis_circ_type,
-				.modify = lib_interface_isis_circuit_type_modify,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/ipv4-routing",
-			.cbs = {
-				.cli_show = cli_show_ip_isis_ipv4,
-				.modify = lib_interface_isis_ipv4_routing_modify,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/ipv6-routing",
-			.cbs = {
-				.cli_show = cli_show_ip_isis_ipv6,
-				.modify = lib_interface_isis_ipv6_routing_modify,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/bfd-monitoring",
-			.cbs = {
-				.modify = lib_interface_isis_bfd_monitoring_modify,
-				.cli_show = cli_show_ip_isis_bfd_monitoring,
-			}
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/csnp-interval",
-			.cbs = {
-				.cli_show = cli_show_ip_isis_csnp_interval,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/csnp-interval/level-1",
-			.cbs = {
-				.modify = lib_interface_isis_csnp_interval_level_1_modify,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/csnp-interval/level-2",
-			.cbs = {
-				.modify = lib_interface_isis_csnp_interval_level_2_modify,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/psnp-interval",
-			.cbs = {
-				.cli_show = cli_show_ip_isis_psnp_interval,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/psnp-interval/level-1",
-			.cbs = {
-				.modify = lib_interface_isis_psnp_interval_level_1_modify,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/psnp-interval/level-2",
-			.cbs = {
-				.modify = lib_interface_isis_psnp_interval_level_2_modify,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/hello/padding",
-			.cbs = {
-				.cli_show = cli_show_ip_isis_hello_padding,
-				.modify = lib_interface_isis_hello_padding_modify,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/hello/interval",
-			.cbs = {
-				.cli_show = cli_show_ip_isis_hello_interval,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/hello/interval/level-1",
-			.cbs = {
-				.modify = lib_interface_isis_hello_interval_level_1_modify,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/hello/interval/level-2",
-			.cbs = {
-				.modify = lib_interface_isis_hello_interval_level_2_modify,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/hello/multiplier",
-			.cbs = {
-				.cli_show = cli_show_ip_isis_hello_multi,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/hello/multiplier/level-1",
-			.cbs = {
-				.modify = lib_interface_isis_hello_multiplier_level_1_modify,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/hello/multiplier/level-2",
-			.cbs = {
-				.modify = lib_interface_isis_hello_multiplier_level_2_modify,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/metric",
-			.cbs = {
-				.cli_show = cli_show_ip_isis_metric,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/metric/level-1",
-			.cbs = {
-				.modify = lib_interface_isis_metric_level_1_modify,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/metric/level-2",
-			.cbs = {
-				.modify = lib_interface_isis_metric_level_2_modify,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/priority",
-			.cbs = {
-				.cli_show = cli_show_ip_isis_priority,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/priority/level-1",
-			.cbs = {
-				.modify = lib_interface_isis_priority_level_1_modify,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/priority/level-2",
-			.cbs = {
-				.modify = lib_interface_isis_priority_level_2_modify,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/network-type",
-			.cbs = {
-				.cli_show = cli_show_ip_isis_network_type,
-				.modify = lib_interface_isis_network_type_modify,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/passive",
-			.cbs = {
-				.cli_show = cli_show_ip_isis_passive,
-				.modify = lib_interface_isis_passive_modify,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/password",
-			.cbs = {
-				.cli_show = cli_show_ip_isis_password,
-				.create = lib_interface_isis_password_create,
-				.destroy = lib_interface_isis_password_destroy,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/password/password",
-			.cbs = {
-				.modify = lib_interface_isis_password_password_modify,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/password/password-type",
-			.cbs = {
-				.modify = lib_interface_isis_password_password_type_modify,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/disable-three-way-handshake",
-			.cbs = {
-				.cli_show = cli_show_ip_isis_threeway_shake,
-				.modify = lib_interface_isis_disable_three_way_handshake_modify,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/multi-topology/ipv4-unicast",
-			.cbs = {
-				.cli_show = cli_show_ip_isis_mt_ipv4_unicast,
-				.modify = lib_interface_isis_multi_topology_ipv4_unicast_modify,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/multi-topology/ipv4-multicast",
-			.cbs = {
-				.cli_show = cli_show_ip_isis_mt_ipv4_multicast,
-				.modify = lib_interface_isis_multi_topology_ipv4_multicast_modify,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/multi-topology/ipv4-management",
-			.cbs = {
-				.cli_show = cli_show_ip_isis_mt_ipv4_mgmt,
-				.modify = lib_interface_isis_multi_topology_ipv4_management_modify,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/multi-topology/ipv6-unicast",
-			.cbs = {
-				.cli_show = cli_show_ip_isis_mt_ipv6_unicast,
-				.modify = lib_interface_isis_multi_topology_ipv6_unicast_modify,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/multi-topology/ipv6-multicast",
-			.cbs = {
-				.cli_show = cli_show_ip_isis_mt_ipv6_multicast,
-				.modify = lib_interface_isis_multi_topology_ipv6_multicast_modify,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/multi-topology/ipv6-management",
-			.cbs = {
-				.cli_show = cli_show_ip_isis_mt_ipv6_mgmt,
-				.modify = lib_interface_isis_multi_topology_ipv6_management_modify,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/multi-topology/ipv6-dstsrc",
-			.cbs = {
-				.cli_show = cli_show_ip_isis_mt_ipv6_dstsrc,
-				.modify = lib_interface_isis_multi_topology_ipv6_dstsrc_modify,
-			},
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/adjacencies/adjacency",
-			.cbs = {
-				.get_next = lib_interface_isis_adjacencies_adjacency_get_next,
-			}
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/adjacencies/adjacency/neighbor-sys-type",
-			.cbs = {
-				.get_elem = lib_interface_isis_adjacencies_adjacency_neighbor_sys_type_get_elem,
-			}
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/adjacencies/adjacency/neighbor-sysid",
-			.cbs = {
-				.get_elem = lib_interface_isis_adjacencies_adjacency_neighbor_sysid_get_elem,
-			}
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/adjacencies/adjacency/neighbor-extended-circuit-id",
-			.cbs = {
-				.get_elem = lib_interface_isis_adjacencies_adjacency_neighbor_extended_circuit_id_get_elem,
-			}
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/adjacencies/adjacency/neighbor-snpa",
-			.cbs = {
-				.get_elem = lib_interface_isis_adjacencies_adjacency_neighbor_snpa_get_elem,
-			}
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/adjacencies/adjacency/hold-timer",
-			.cbs = {
-				.get_elem = lib_interface_isis_adjacencies_adjacency_hold_timer_get_elem,
-			}
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/adjacencies/adjacency/neighbor-priority",
-			.cbs = {
-				.get_elem = lib_interface_isis_adjacencies_adjacency_neighbor_priority_get_elem,
-			}
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/adjacencies/adjacency/state",
-			.cbs = {
-				.get_elem = lib_interface_isis_adjacencies_adjacency_state_get_elem,
-			}
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/event-counters/adjacency-changes",
-			.cbs = {
-				.get_elem = lib_interface_isis_event_counters_adjacency_changes_get_elem,
-			}
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/event-counters/adjacency-number",
-			.cbs = {
-				.get_elem = lib_interface_isis_event_counters_adjacency_number_get_elem,
-			}
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/event-counters/init-fails",
-			.cbs = {
-				.get_elem = lib_interface_isis_event_counters_init_fails_get_elem,
-			}
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/event-counters/adjacency-rejects",
-			.cbs = {
-				.get_elem = lib_interface_isis_event_counters_adjacency_rejects_get_elem,
-			}
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/event-counters/id-len-mismatch",
-			.cbs = {
-				.get_elem = lib_interface_isis_event_counters_id_len_mismatch_get_elem,
-			}
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/event-counters/max-area-addresses-mismatch",
-			.cbs = {
-				.get_elem = lib_interface_isis_event_counters_max_area_addresses_mismatch_get_elem,
-			}
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/event-counters/authentication-type-fails",
-			.cbs = {
-				.get_elem = lib_interface_isis_event_counters_authentication_type_fails_get_elem,
-			}
-		},
-		{
-			.xpath = "/frr-interface:lib/interface/frr-isisd:isis/event-counters/authentication-fails",
-			.cbs = {
-				.get_elem = lib_interface_isis_event_counters_authentication_fails_get_elem,
-			}
-		},
-		{
-			.xpath = NULL,
-		},
-	}
-};
diff --git a/isisd/isis_pdu.c b/isisd/isis_pdu.c
index a637ff003..71249cf65 100644
--- a/isisd/isis_pdu.c
+++ b/isisd/isis_pdu.c
@@ -58,6 +58,7 @@
 #include "isisd/fabricd.h"
 #include "isisd/isis_tx_queue.h"
 #include "isisd/isis_pdu_counter.h"
+#include "isisd/isis_nb.h"
 
 static int ack_lsp(struct isis_lsp_hdr *hdr, struct isis_circuit *circuit,
 		   int level)
diff --git a/isisd/isisd.c b/isisd/isisd.c
index 029a9e068..f15d7a9c7 100644
--- a/isisd/isisd.c
+++ b/isisd/isisd.c
@@ -57,6 +57,7 @@
 #include "isisd/isis_te.h"
 #include "isisd/isis_mt.h"
 #include "isisd/fabricd.h"
+#include "isisd/isis_nb.h"
 
 struct isis *isis = NULL;
 
diff --git a/isisd/isisd.h b/isisd/isisd.h
index f825b6ecb..052cc1092 100644
--- a/isisd/isisd.h
+++ b/isisd/isisd.h
@@ -219,52 +219,6 @@ int isis_area_passwd_cleartext_set(struct isis_area *area, int level,
 int isis_area_passwd_hmac_md5_set(struct isis_area *area, int level,
 				  const char *passwd, uint8_t snp_auth);
 
-extern const struct frr_yang_module_info frr_isisd_info;
-extern void isis_northbound_init(void);
-
-/* YANG northbound notifications */
-extern void isis_notif_db_overload(const struct isis_area *area, bool overload);
-extern void isis_notif_lsp_too_large(const struct isis_circuit *circuit,
-				     uint32_t pdu_size, const char *lsp_id);
-extern void isis_notif_if_state_change(const struct isis_circuit *circuit,
-				       bool down);
-extern void isis_notif_corrupted_lsp(const struct isis_area *area,
-				     const char *lsp_id); /* currently unused */
-extern void isis_notif_lsp_exceed_max(const struct isis_area *area,
-				      const char *lsp_id);
-extern void
-isis_notif_max_area_addr_mismatch(const struct isis_circuit *circuit,
-				  uint8_t max_area_addrs, const char *raw_pdu);
-extern void
-isis_notif_authentication_type_failure(const struct isis_circuit *circuit,
-				       const char *raw_pdu);
-extern void
-isis_notif_authentication_failure(const struct isis_circuit *circuit,
-				  const char *raw_pdu);
-extern void isis_notif_adj_state_change(const struct isis_adjacency *adj,
-					int new_state, const char *reason);
-extern void isis_notif_reject_adjacency(const struct isis_circuit *circuit,
-					const char *reason,
-					const char *raw_pdu);
-extern void isis_notif_area_mismatch(const struct isis_circuit *circuit,
-				     const char *raw_pdu);
-extern void isis_notif_lsp_received(const struct isis_circuit *circuit,
-				    const char *lsp_id, uint32_t seqno,
-				    uint32_t timestamp, const char *sys_id);
-extern void isis_notif_lsp_gen(const struct isis_area *area, const char *lsp_id,
-			       uint32_t seqno, uint32_t timestamp);
-extern void isis_notif_id_len_mismatch(const struct isis_circuit *circuit,
-				       uint8_t rcv_id_len, const char *raw_pdu);
-extern void isis_notif_version_skew(const struct isis_circuit *circuit,
-				    uint8_t version, const char *raw_pdu);
-extern void isis_notif_lsp_error(const struct isis_circuit *circuit,
-				 const char *lsp_id, const char *raw_pdu,
-				 uint32_t offset, uint8_t tlv_type);
-extern void isis_notif_seqno_skipped(const struct isis_circuit *circuit,
-				     const char *lsp_id);
-extern void isis_notif_own_lsp_purge(const struct isis_circuit *circuit,
-				     const char *lsp_id);
-
 /* Master of threads. */
 extern struct thread_master *master;
 
diff --git a/isisd/subdir.am b/isisd/subdir.am
index 24f24022a..e77fef41d 100644
--- a/isisd/subdir.am
+++ b/isisd/subdir.am
@@ -39,6 +39,7 @@ noinst_HEADERS += \
 	isisd/isis_memory.h \
 	isisd/isis_misc.h \
 	isisd/isis_mt.h \
+	isisd/isis_nb.h \
 	isisd/isis_network.h \
 	isisd/isis_pdu.h \
 	isisd/isis_pdu_counter.h \
@@ -54,7 +55,6 @@ noinst_HEADERS += \
 	isisd/isisd.h \
 	isisd/iso_checksum.h \
 	isisd/fabricd.h \
-	isisd/isis_cli.h \
 	# end
 
 LIBISIS_SOURCES = \
@@ -99,7 +99,10 @@ ISIS_LDADD_COMMON = lib/libfrr.la $(LIBCAP)
 
 isisd_libisis_a_SOURCES = \
 	$(LIBISIS_SOURCES) \
-	isisd/isis_northbound.c \
+	isisd/isis_nb.c \
+	isisd/isis_nb_config.c \
+	isisd/isis_nb_notifications.c \
+	isisd/isis_nb_state.c \
 	isisd/isis_cli.c \
 	#end