Merge pull request #8561 from opensourcerouting/msdp-refactor-v2

pimd: rework MSDP mesh groups

25 files changed, 1103 insertions, 796 deletions

diff --git a/pimd/pim_cmd.c b/pimd/pim_cmd.c
index f6072b177..b3d444465 100644
--- a/pimd/pim_cmd.c
+++ b/pimd/pim_cmd.c
@@ -3853,6 +3853,54 @@ static const char *pim_cli_get_vrf_name(struct vty *vty)
 	return yang_dnode_get_string(vrf_node, "./name");
 }
 
+/**
+ * Compatibility function to keep the legacy mesh group CLI behavior:
+ * Delete group when there are no more configurations in it.
+ *
+ * NOTE:
+ * Don't forget to call `nb_cli_apply_changes` after this.
+ */
+static void pim_cli_legacy_mesh_group_behavior(struct vty *vty,
+					       const char *gname)
+{
+	const char *vrfname;
+	char xpath_value[XPATH_MAXLEN];
+	char xpath_member_value[XPATH_MAXLEN];
+	const struct lyd_node *member_dnode;
+
+	vrfname = pim_cli_get_vrf_name(vty);
+	if (vrfname == NULL)
+		return;
+
+	/* Get mesh group base XPath. */
+	snprintf(xpath_value, sizeof(xpath_value),
+		 FRR_PIM_AF_XPATH "/msdp-mesh-groups[name='%s']",
+		 "frr-pim:pimd", "pim", vrfname, "frr-routing:ipv4", gname);
+	/* Group must exists, otherwise just quit. */
+	if (!yang_dnode_exists(vty->candidate_config->dnode, xpath_value))
+		return;
+
+	/* Group members check: */
+	strlcpy(xpath_member_value, xpath_value, sizeof(xpath_member_value));
+	strlcat(xpath_member_value, "/members", sizeof(xpath_member_value));
+	if (yang_dnode_exists(vty->candidate_config->dnode,
+			      xpath_member_value)) {
+		member_dnode = yang_dnode_get(vty->candidate_config->dnode,
+					      xpath_member_value);
+		if (!yang_is_last_list_dnode(member_dnode))
+			return;
+	}
+
+	/* Source address check: */
+	strlcpy(xpath_member_value, xpath_value, sizeof(xpath_member_value));
+	strlcat(xpath_member_value, "/source", sizeof(xpath_member_value));
+	if (yang_dnode_exists(vty->candidate_config->dnode, xpath_member_value))
+		return;
+
+	/* No configurations found: delete it. */
+	nb_cli_enqueue_change(vty, xpath_value, NB_OP_DESTROY, NULL);
+}
+
 DEFUN (clear_ip_interfaces,
        clear_ip_interfaces_cmd,
        "clear ip interfaces [vrf NAME]",
@@ -9685,305 +9733,199 @@ DEFUN (no_ip_msdp_peer,
 	return nb_cli_apply_changes(vty, NULL);
 }
 
-DEFUN (ip_msdp_mesh_group_member,
-       ip_msdp_mesh_group_member_cmd,
-       "ip msdp mesh-group WORD member A.B.C.D",
-       IP_STR
-       CFG_MSDP_STR
-       "Configure MSDP mesh-group\n"
-       "mesh group name\n"
-       "mesh group member\n"
-       "peer ip address\n")
+DEFPY(ip_msdp_mesh_group_member,
+      ip_msdp_mesh_group_member_cmd,
+      "ip msdp mesh-group WORD$gname member A.B.C.D$maddr",
+      IP_STR
+      CFG_MSDP_STR
+      "Configure MSDP mesh-group\n"
+      "Mesh group name\n"
+      "Mesh group member\n"
+      "Peer IP address\n")
 {
 	const char *vrfname;
-	char msdp_mesh_group_name_xpath[XPATH_MAXLEN];
-	char msdp_mesh_group_member_xpath[XPATH_MAXLEN];
+	char xpath_value[XPATH_MAXLEN];
 
 	vrfname = pim_cli_get_vrf_name(vty);
 	if (vrfname == NULL)
 		return CMD_WARNING_CONFIG_FAILED;
 
-	snprintf(msdp_mesh_group_name_xpath, sizeof(msdp_mesh_group_name_xpath),
-		 FRR_PIM_AF_XPATH,
-		 "frr-pim:pimd", "pim", vrfname, "frr-routing:ipv4");
-	strlcat(msdp_mesh_group_name_xpath, "/msdp-mesh-group/mesh-group-name",
-		sizeof(msdp_mesh_group_name_xpath));
-	snprintf(msdp_mesh_group_member_xpath,
-		 sizeof(msdp_mesh_group_member_xpath),
-		 FRR_PIM_AF_XPATH,
-		 "frr-pim:pimd", "pim", vrfname, "frr-routing:ipv4");
-	strlcat(msdp_mesh_group_member_xpath, "/msdp-mesh-group/member-ip",
-		sizeof(msdp_mesh_group_member_xpath));
+	/* Create mesh group. */
+	snprintf(xpath_value, sizeof(xpath_value),
+		 FRR_PIM_AF_XPATH "/msdp-mesh-groups[name='%s']",
+		 "frr-pim:pimd", "pim", vrfname, "frr-routing:ipv4", gname);
+	nb_cli_enqueue_change(vty, xpath_value, NB_OP_CREATE, NULL);
 
-	nb_cli_enqueue_change(vty, msdp_mesh_group_name_xpath, NB_OP_MODIFY,
-			      argv[3]->arg);
-	nb_cli_enqueue_change(vty, msdp_mesh_group_member_xpath, NB_OP_CREATE,
-			      argv[5]->arg);
+	/* Create mesh group member. */
+	strlcat(xpath_value, "/members[address='", sizeof(xpath_value));
+	strlcat(xpath_value, maddr_str, sizeof(xpath_value));
+	strlcat(xpath_value, "']", sizeof(xpath_value));
+	nb_cli_enqueue_change(vty, xpath_value, NB_OP_CREATE, NULL);
 
 	return nb_cli_apply_changes(vty, NULL);
 }
 
-DEFUN (no_ip_msdp_mesh_group_member,
-       no_ip_msdp_mesh_group_member_cmd,
-       "no ip msdp mesh-group WORD member A.B.C.D",
-       NO_STR
-       IP_STR
-       CFG_MSDP_STR
-       "Delete MSDP mesh-group member\n"
-       "mesh group name\n"
-       "mesh group member\n"
-       "peer ip address\n")
+DEFPY(no_ip_msdp_mesh_group_member,
+      no_ip_msdp_mesh_group_member_cmd,
+      "no ip msdp mesh-group WORD$gname member A.B.C.D$maddr",
+      NO_STR
+      IP_STR
+      CFG_MSDP_STR
+      "Delete MSDP mesh-group member\n"
+      "Mesh group name\n"
+      "Mesh group member\n"
+      "Peer IP address\n")
 {
 	const char *vrfname;
-	char pim_af_xpath[XPATH_MAXLEN];
-	char mesh_group_xpath[XPATH_MAXLEN + 32];
-	char group_member_list_xpath[XPATH_MAXLEN + 64];
-	char group_member_xpath[XPATH_MAXLEN + 128];
-	char source_xpath[XPATH_MAXLEN + 64];
-	char mesh_group_name_xpath[XPATH_MAXLEN + 64];
-	const char *mesh_group_name;
-	const struct lyd_node *member_dnode;
+	char xpath_value[XPATH_MAXLEN];
+	char xpath_member_value[XPATH_MAXLEN];
 
 	vrfname = pim_cli_get_vrf_name(vty);
 	if (vrfname == NULL)
 		return CMD_WARNING_CONFIG_FAILED;
 
-	snprintf(pim_af_xpath, sizeof(pim_af_xpath), FRR_PIM_AF_XPATH,
-		 "frr-pim:pimd", "pim", vrfname, "frr-routing:ipv4");
+	/* Get mesh group base XPath. */
+	snprintf(xpath_value, sizeof(xpath_value),
+		 FRR_PIM_AF_XPATH "/msdp-mesh-groups[name='%s']",
+		 "frr-pim:pimd", "pim", vrfname, "frr-routing:ipv4", gname);
 
-	snprintf(mesh_group_xpath, sizeof(mesh_group_xpath),
-		 "%s/msdp-mesh-group", pim_af_xpath);
-
-	snprintf(group_member_list_xpath, sizeof(group_member_list_xpath),
-		 "%s/msdp-mesh-group/member-ip", pim_af_xpath);
-
-	snprintf(group_member_xpath, sizeof(group_member_xpath), "%s[.='%s']",
-		 group_member_list_xpath, argv[6]->arg);
-
-	snprintf(source_xpath, sizeof(source_xpath),
-		 "%s/msdp-mesh-group/source-ip", pim_af_xpath);
-
-	snprintf(mesh_group_name_xpath, sizeof(mesh_group_name_xpath),
-		 "%s/msdp-mesh-group/mesh-group-name", pim_af_xpath);
-
-	if (yang_dnode_exists(running_config->dnode, mesh_group_name_xpath)
-	    == true) {
-		mesh_group_name = yang_dnode_get_string(running_config->dnode,
-							mesh_group_name_xpath);
-		if (strcmp(mesh_group_name, argv[4]->arg)) {
-			vty_out(vty, "%% mesh-group does not exist\n");
-			return CMD_WARNING_CONFIG_FAILED;
-		}
+	if (!yang_dnode_exists(vty->candidate_config->dnode, xpath_value)) {
+		vty_out(vty, "%% mesh-group does not exist\n");
+		return CMD_WARNING_CONFIG_FAILED;
 	}
 
-	if (yang_dnode_exists(vty->candidate_config->dnode,
-			      group_member_xpath)) {
-		if (!yang_dnode_exists(vty->candidate_config->dnode,
-				       source_xpath)) {
-			member_dnode = yang_dnode_get(
-				vty->candidate_config->dnode,
-				group_member_xpath);
-			if (yang_is_last_list_dnode(member_dnode)) {
-				nb_cli_enqueue_change(vty, mesh_group_xpath,
-						      NB_OP_DESTROY, NULL);
-				return nb_cli_apply_changes(vty, NULL);
-			}
-			nb_cli_enqueue_change(vty, group_member_list_xpath,
-					      NB_OP_DESTROY, argv[6]->arg);
-			return nb_cli_apply_changes(vty, NULL);
-		}
-		nb_cli_enqueue_change(vty, group_member_list_xpath,
-				      NB_OP_DESTROY, argv[6]->arg);
-		return nb_cli_apply_changes(vty, NULL);
+	/* Remove mesh group member. */
+	strlcpy(xpath_member_value, xpath_value, sizeof(xpath_member_value));
+	strlcat(xpath_member_value, "/members[address='",
+		sizeof(xpath_member_value));
+	strlcat(xpath_member_value, maddr_str, sizeof(xpath_member_value));
+	strlcat(xpath_member_value, "']", sizeof(xpath_member_value));
+	if (!yang_dnode_exists(vty->candidate_config->dnode,
+			       xpath_member_value)) {
+		vty_out(vty, "%% mesh-group member does not exist\n");
+		return CMD_WARNING_CONFIG_FAILED;
 	}
 
-	vty_out(vty, "%% mesh-group member does not exist\n");
+	nb_cli_enqueue_change(vty, xpath_value, NB_OP_DESTROY, NULL);
 
-	return CMD_SUCCESS;
+	/*
+	 * If this is the last member, then we must remove the group altogether
+	 * to not break legacy CLI behaviour.
+	 */
+	pim_cli_legacy_mesh_group_behavior(vty, gname);
+
+	return nb_cli_apply_changes(vty, NULL);
 }
 
-DEFUN (ip_msdp_mesh_group_source,
-       ip_msdp_mesh_group_source_cmd,
-       "ip msdp mesh-group WORD source A.B.C.D",
-       IP_STR
-       CFG_MSDP_STR
-       "Configure MSDP mesh-group\n"
-       "mesh group name\n"
-       "mesh group local address\n"
-       "source ip address for the TCP connection\n")
+DEFPY(ip_msdp_mesh_group_source,
+      ip_msdp_mesh_group_source_cmd,
+      "ip msdp mesh-group WORD$gname source A.B.C.D$saddr",
+      IP_STR
+      CFG_MSDP_STR
+      "Configure MSDP mesh-group\n"
+      "Mesh group name\n"
+      "Mesh group local address\n"
+      "Source IP address for the TCP connection\n")
 {
 	const char *vrfname;
-	char msdp_mesh_source_ip_xpath[XPATH_MAXLEN];
-	char msdp_mesh_group_name_xpath[XPATH_MAXLEN];
+	char xpath_value[XPATH_MAXLEN];
 
 	vrfname = pim_cli_get_vrf_name(vty);
 	if (vrfname == NULL)
 		return CMD_WARNING_CONFIG_FAILED;
 
-	snprintf(msdp_mesh_group_name_xpath, sizeof(msdp_mesh_group_name_xpath),
-		 FRR_PIM_AF_XPATH,
-		 "frr-pim:pimd", "pim", vrfname, "frr-routing:ipv4");
-	strlcat(msdp_mesh_group_name_xpath, "/msdp-mesh-group/mesh-group-name",
-		sizeof(msdp_mesh_group_name_xpath));
-
-	snprintf(msdp_mesh_source_ip_xpath, sizeof(msdp_mesh_source_ip_xpath),
-		 FRR_PIM_AF_XPATH,
-		 "frr-pim:pimd", "pim", vrfname, "frr-routing:ipv4");
-	strlcat(msdp_mesh_source_ip_xpath, "/msdp-mesh-group/source-ip",
-		sizeof(msdp_mesh_source_ip_xpath));
+	/* Create mesh group. */
+	snprintf(xpath_value, sizeof(xpath_value),
+		 FRR_PIM_AF_XPATH "/msdp-mesh-groups[name='%s']",
+		 "frr-pim:pimd", "pim", vrfname, "frr-routing:ipv4", gname);
+	nb_cli_enqueue_change(vty, xpath_value, NB_OP_CREATE, NULL);
 
-	nb_cli_enqueue_change(vty, msdp_mesh_group_name_xpath, NB_OP_MODIFY,
-			      argv[3]->arg);
-	nb_cli_enqueue_change(vty, msdp_mesh_source_ip_xpath, NB_OP_MODIFY,
-			      argv[5]->arg);
+	/* Create mesh group member. */
+	strlcat(xpath_value, "/source", sizeof(xpath_value));
+	nb_cli_enqueue_change(vty, xpath_value, NB_OP_MODIFY, saddr_str);
 
 	return nb_cli_apply_changes(vty, NULL);
 }
 
-DEFUN (no_ip_msdp_mesh_group_source,
-       no_ip_msdp_mesh_group_source_cmd,
-       "no ip msdp mesh-group WORD source [A.B.C.D]",
-       NO_STR
-       IP_STR
-       CFG_MSDP_STR
-       "Delete MSDP mesh-group source\n"
-       "mesh group name\n"
-       "mesh group source\n"
-       "mesh group local address\n")
+DEFPY(no_ip_msdp_mesh_group_source,
+      no_ip_msdp_mesh_group_source_cmd,
+      "no ip msdp mesh-group WORD$gname source [A.B.C.D]",
+      NO_STR
+      IP_STR
+      CFG_MSDP_STR
+      "Delete MSDP mesh-group source\n"
+      "Mesh group name\n"
+      "Mesh group source\n"
+      "Mesh group local address\n")
 {
 	const char *vrfname;
-	char msdp_mesh_xpath[XPATH_MAXLEN];
-	char source_xpath[XPATH_MAXLEN];
-	char group_member_xpath[XPATH_MAXLEN];
-	char mesh_group_name_xpath[XPATH_MAXLEN];
-	const char *mesh_group_name;
+	char xpath_value[XPATH_MAXLEN];
 
 	vrfname = pim_cli_get_vrf_name(vty);
 	if (vrfname == NULL)
 		return CMD_WARNING_CONFIG_FAILED;
 
-	snprintf(msdp_mesh_xpath, sizeof(msdp_mesh_xpath),
-		 FRR_PIM_AF_XPATH,
-		 "frr-pim:pimd", "pim", vrfname, "frr-routing:ipv4");
-	strlcat(msdp_mesh_xpath, "/msdp-mesh-group", sizeof(msdp_mesh_xpath));
+	/* Get mesh group base XPath. */
+	snprintf(xpath_value, sizeof(xpath_value),
+		 FRR_PIM_AF_XPATH "/msdp-mesh-groups[name='%s']",
+		 "frr-pim:pimd", "pim", vrfname, "frr-routing:ipv4", gname);
+	nb_cli_enqueue_change(vty, xpath_value, NB_OP_CREATE, NULL);
 
-	snprintf(source_xpath, sizeof(source_xpath),
-		 FRR_PIM_AF_XPATH,
-		 "frr-pim:pimd", "pim", vrfname, "frr-routing:ipv4");
-	strlcat(source_xpath, "/msdp-mesh-group/source-ip",
-		sizeof(source_xpath));
+	/* Create mesh group member. */
+	strlcat(xpath_value, "/source", sizeof(xpath_value));
+	nb_cli_enqueue_change(vty, xpath_value, NB_OP_DESTROY, NULL);
 
-	snprintf(group_member_xpath,
-		 sizeof(group_member_xpath),
-		 FRR_PIM_AF_XPATH,
-		 "frr-pim:pimd", "pim", vrfname, "frr-routing:ipv4");
-	strlcat(group_member_xpath, "/msdp-mesh-group/member-ip",
-		sizeof(group_member_xpath));
+	/*
+	 * If this is the last member, then we must remove the group altogether
+	 * to not break legacy CLI behaviour.
+	 */
+	pim_cli_legacy_mesh_group_behavior(vty, gname);
 
-	snprintf(mesh_group_name_xpath, sizeof(mesh_group_name_xpath),
-		 FRR_PIM_AF_XPATH,
-		 "frr-pim:pimd", "pim", vrfname, "frr-routing:ipv4");
-	strlcat(mesh_group_name_xpath, "/msdp-mesh-group/mesh-group-name",
-		sizeof(mesh_group_name_xpath));
-
-	if (yang_dnode_exists(running_config->dnode, mesh_group_name_xpath)
-	    == true) {
-		mesh_group_name = yang_dnode_get_string(running_config->dnode,
-							mesh_group_name_xpath);
-		if (strcmp(mesh_group_name, argv[4]->arg)) {
-			vty_out(vty, "%% mesh-group does not exist\n");
-			return CMD_WARNING_CONFIG_FAILED;
-		}
-	}
-
-	if (!yang_dnode_exists(vty->candidate_config->dnode,
-			       group_member_xpath)) {
-		nb_cli_enqueue_change(vty, msdp_mesh_xpath, NB_OP_DESTROY,
-				      NULL);
-		return nb_cli_apply_changes(vty, NULL);
-	}
-	nb_cli_enqueue_change(vty, source_xpath, NB_OP_DESTROY, NULL);
 	return nb_cli_apply_changes(vty, NULL);
 }
 
-DEFUN (no_ip_msdp_mesh_group,
-       no_ip_msdp_mesh_group_cmd,
-       "no ip msdp mesh-group [WORD]",
-       NO_STR
-       IP_STR
-       CFG_MSDP_STR
-       "Delete MSDP mesh-group\n"
-       "mesh group name")
+DEFPY(no_ip_msdp_mesh_group,
+      no_ip_msdp_mesh_group_cmd,
+      "no ip msdp mesh-group WORD$gname",
+      NO_STR
+      IP_STR
+      CFG_MSDP_STR
+      "Delete MSDP mesh-group\n"
+      "Mesh group name")
 {
 	const char *vrfname;
-	const char *mesh_group_name;
-	char xpath[XPATH_MAXLEN];
-	char msdp_mesh_xpath[XPATH_MAXLEN];
+	char xpath_value[XPATH_MAXLEN];
 
 	vrfname = pim_cli_get_vrf_name(vty);
 	if (vrfname == NULL)
 		return CMD_WARNING_CONFIG_FAILED;
 
-	if (argc == 5) {
-		snprintf(xpath, sizeof(xpath), FRR_PIM_AF_XPATH, "frr-pim:pimd",
-			 "pim", vrfname, "frr-routing:ipv4");
-		strlcat(xpath, "/msdp-mesh-group/mesh-group-name",
-			sizeof(xpath));
-
-		if (yang_dnode_exists(running_config->dnode, xpath) == true) {
-			mesh_group_name =
-				yang_dnode_get_string(running_config->dnode,
-						      xpath);
-
-			if (strcmp(mesh_group_name, argv[4]->arg)) {
-				vty_out(vty, "%% mesh-group does not exist\n");
-				return CMD_WARNING_CONFIG_FAILED;
-			}
-		}
-	}
-
-	snprintf(msdp_mesh_xpath, sizeof(msdp_mesh_xpath),
-		 FRR_PIM_AF_XPATH,
-		 "frr-pim:pimd", "pim", vrfname, "frr-routing:ipv4");
-	strlcat(msdp_mesh_xpath, "/msdp-mesh-group", sizeof(msdp_mesh_xpath));
+	/* Get mesh group base XPath. */
+	snprintf(xpath_value, sizeof(xpath_value),
+		 FRR_PIM_AF_XPATH "/msdp-mesh-groups[name='%s']",
+		 "frr-pim:pimd", "pim", vrfname, "frr-routing:ipv4", gname);
+	if (!yang_dnode_exists(vty->candidate_config->dnode, xpath_value))
+		return CMD_SUCCESS;
 
-	nb_cli_enqueue_change(vty, msdp_mesh_xpath, NB_OP_DESTROY, NULL);
+	nb_cli_enqueue_change(vty, xpath_value, NB_OP_DESTROY, NULL);
 	return nb_cli_apply_changes(vty, NULL);
 }
 
-static void print_empty_json_obj(struct vty *vty)
-{
-	json_object *json;
-	json = json_object_new_object();
-	vty_out(vty, "%s\n",
-		json_object_to_json_string_ext(json, JSON_C_TO_STRING_PRETTY));
-	json_object_free(json);
-}
-
-static void ip_msdp_show_mesh_group(struct pim_instance *pim, struct vty *vty,
-				    bool uj)
+static void ip_msdp_show_mesh_group(struct vty *vty, struct pim_msdp_mg *mg,
+				    struct json_object *json)
 {
 	struct listnode *mbrnode;
 	struct pim_msdp_mg_mbr *mbr;
-	struct pim_msdp_mg *mg = pim->msdp.mg;
 	char mbr_str[INET_ADDRSTRLEN];
 	char src_str[INET_ADDRSTRLEN];
 	char state_str[PIM_MSDP_STATE_STRLEN];
 	enum pim_msdp_peer_state state;
-	json_object *json = NULL;
 	json_object *json_mg_row = NULL;
 	json_object *json_members = NULL;
 	json_object *json_row = NULL;
 
-	if (!mg) {
-		if (uj)
-			print_empty_json_obj(vty);
-		return;
-	}
-
 	pim_inet4_dump("<source?>", mg->src_ip, src_str, sizeof(src_str));
-	if (uj) {
-		json = json_object_new_object();
+	if (json) {
 		/* currently there is only one mesh group but we should still
 		 * make
 		 * it a dict with mg-name as key */
@@ -10005,7 +9947,7 @@ static void ip_msdp_show_mesh_group(struct pim_instance *pim, struct vty *vty,
 			state = PIM_MSDP_DISABLED;
 		}
 		pim_msdp_state_dump(state, state_str, sizeof(state_str));
-		if (uj) {
+		if (json) {
 			json_row = json_object_new_object();
 			json_object_string_add(json_row, "member", mbr_str);
 			json_object_string_add(json_row, "state", state_str);
@@ -10020,12 +9962,8 @@ static void ip_msdp_show_mesh_group(struct pim_instance *pim, struct vty *vty,
 		}
 	}
 
-	if (uj) {
+	if (json)
 		json_object_object_add(json, mg->mesh_group_name, json_mg_row);
-		vty_out(vty, "%s\n", json_object_to_json_string_ext(
-				json, JSON_C_TO_STRING_PRETTY));
-		json_object_free(json);
-	}
 }
 
 DEFUN (show_ip_msdp_mesh_group,
@@ -10040,12 +9978,34 @@ DEFUN (show_ip_msdp_mesh_group,
 {
 	bool uj = use_json(argc, argv);
 	int idx = 2;
+	struct pim_msdp_mg *mg;
 	struct vrf *vrf = pim_cmd_lookup_vrf(vty, argv, argc, &idx);
+	struct pim_instance *pim = vrf->info;
+	struct json_object *json = NULL;
 
 	if (!vrf)
 		return CMD_WARNING;
 
-	ip_msdp_show_mesh_group(vrf->info, vty, uj);
+	/* Quick case: list is empty. */
+	if (SLIST_EMPTY(&pim->msdp.mglist)) {
+		if (uj)
+			vty_out(vty, "{}\n");
+
+		return CMD_SUCCESS;
+	}
+
+	if (uj)
+		json = json_object_new_object();
+
+	SLIST_FOREACH (mg, &pim->msdp.mglist, mg_entry)
+		ip_msdp_show_mesh_group(vty, mg, json);
+
+	if (uj) {
+		vty_out(vty, "%s\n",
+			json_object_to_json_string_ext(
+				json, JSON_C_TO_STRING_PRETTY));
+		json_object_free(json);
+	}
 
 	return CMD_SUCCESS;
 }
@@ -10061,23 +10021,32 @@ DEFUN (show_ip_msdp_mesh_group_vrf_all,
        JSON_STR)
 {
 	bool uj = use_json(argc, argv);
+	struct json_object *json = NULL, *vrf_json = NULL;
+	struct pim_instance *pim;
+	struct pim_msdp_mg *mg;
 	struct vrf *vrf;
-	bool first = true;
 
 	if (uj)
-		vty_out(vty, "{ ");
+		json = json_object_new_object();
+
 	RB_FOREACH (vrf, vrf_name_head, &vrfs_by_name) {
 		if (uj) {
-			if (!first)
-				vty_out(vty, ", ");
-			vty_out(vty, " \"%s\": ", vrf->name);
-			first = false;
+			vrf_json = json_object_new_object();
+			json_object_object_add(json, vrf->name, vrf_json);
 		} else
 			vty_out(vty, "VRF: %s\n", vrf->name);
-		ip_msdp_show_mesh_group(vrf->info, vty, uj);
+
+		pim = vrf->info;
+		SLIST_FOREACH (mg, &pim->msdp.mglist, mg_entry)
+			ip_msdp_show_mesh_group(vty, mg, vrf_json);
+	}
+
+	if (uj) {
+		vty_out(vty, "%s\n",
+			json_object_to_json_string_ext(
+				json, JSON_C_TO_STRING_PRETTY));
+		json_object_free(json);
 	}
-	if (uj)
-		vty_out(vty, "}\n");
 
 	return CMD_SUCCESS;
 }
diff --git a/pimd/pim_msdp.c b/pimd/pim_msdp.c
index 9cf73c38c..095c6de54 100644
--- a/pimd/pim_msdp.c
+++ b/pimd/pim_msdp.c
@@ -58,8 +58,6 @@ static void pim_msdp_sa_deref(struct pim_msdp_sa *sa,
 			      enum pim_msdp_sa_flags flags);
 static int pim_msdp_mg_mbr_comp(const void *p1, const void *p2);
 static void pim_msdp_mg_mbr_free(struct pim_msdp_mg_mbr *mbr);
-static void pim_msdp_mg_mbr_do_del(struct pim_msdp_mg *mg,
-				   struct pim_msdp_mg_mbr *mbr);
 
 /************************ SA cache management ******************************/
 static void pim_msdp_sa_timer_expiry_log(struct pim_msdp_sa *sa,
@@ -1252,27 +1250,33 @@ static int pim_msdp_peer_comp(const void *p1, const void *p2)
 }
 
 /************************** Mesh group management **************************/
-static void pim_msdp_mg_free(struct pim_instance *pim)
+void pim_msdp_mg_free(struct pim_instance *pim, struct pim_msdp_mg **mgp)
 {
-	struct pim_msdp_mg *mg = pim->msdp.mg;
+	struct pim_msdp_mg_mbr *mbr;
+	struct listnode *n, *nn;
 
-	/* If the mesh-group has valid member or src_ip don't delete it */
-	if (!mg || mg->mbr_cnt || (mg->src_ip.s_addr != INADDR_ANY)) {
+	if (*mgp == NULL)
 		return;
-	}
+
+	/* SIP is being removed - tear down all active peer sessions */
+	for (ALL_LIST_ELEMENTS((*mgp)->mbr_list, n, nn, mbr))
+		pim_msdp_mg_mbr_del((*mgp), mbr);
 
 	if (PIM_DEBUG_MSDP_EVENTS) {
-		zlog_debug("MSDP mesh-group %s deleted", mg->mesh_group_name);
+		zlog_debug("MSDP mesh-group %s deleted",
+			   (*mgp)->mesh_group_name);
 	}
-	XFREE(MTYPE_PIM_MSDP_MG_NAME, mg->mesh_group_name);
 
-	if (mg->mbr_list)
-		list_delete(&mg->mbr_list);
+	XFREE(MTYPE_PIM_MSDP_MG_NAME, (*mgp)->mesh_group_name);
+
+	if ((*mgp)->mbr_list)
+		list_delete(&(*mgp)->mbr_list);
 
-	XFREE(MTYPE_PIM_MSDP_MG, pim->msdp.mg);
+	XFREE(MTYPE_PIM_MSDP_MG, (*mgp));
 }
 
-static struct pim_msdp_mg *pim_msdp_mg_new(const char *mesh_group_name)
+struct pim_msdp_mg *pim_msdp_mg_new(struct pim_instance *pim,
+				    const char *mesh_group_name)
 {
 	struct pim_msdp_mg *mg;
 
@@ -1286,52 +1290,10 @@ static struct pim_msdp_mg *pim_msdp_mg_new(const char *mesh_group_name)
 	if (PIM_DEBUG_MSDP_EVENTS) {
 		zlog_debug("MSDP mesh-group %s created", mg->mesh_group_name);
 	}
-	return mg;
-}
-
-enum pim_msdp_err pim_msdp_mg_del(struct pim_instance *pim,
-				  const char *mesh_group_name)
-{
-	struct pim_msdp_mg *mg = pim->msdp.mg;
-	struct pim_msdp_mg_mbr *mbr;
-
-	if (!mg
-	    || (mesh_group_name
-		&& strcmp(mg->mesh_group_name, mesh_group_name))) {
-		return PIM_MSDP_ERR_NO_MG;
-	}
-
-	/* delete all the mesh-group members */
-	while (!list_isempty(mg->mbr_list)) {
-		mbr = listnode_head(mg->mbr_list);
-		pim_msdp_mg_mbr_do_del(mg, mbr);
-	}
-
-	/* clear src ip */
-	mg->src_ip.s_addr = INADDR_ANY;
-
-	/* free up the mesh-group */
-	pim_msdp_mg_free(pim);
-	return PIM_MSDP_ERR_NONE;
-}
-
-static enum pim_msdp_err pim_msdp_mg_add(struct pim_instance *pim,
-					 const char *mesh_group_name)
-{
-	if (pim->msdp.mg) {
-		if (!strcmp(pim->msdp.mg->mesh_group_name, mesh_group_name)) {
-			return PIM_MSDP_ERR_NONE;
-		}
-		/* currently only one mesh-group can exist at a time */
-		return PIM_MSDP_ERR_MAX_MESH_GROUPS;
-	}
 
-	pim->msdp.mg = pim_msdp_mg_new(mesh_group_name);
-	if (!pim->msdp.mg) {
-		return PIM_MSDP_ERR_OOM;
-	}
+	SLIST_INSERT_HEAD(&pim->msdp.mglist, mg, mg_entry);
 
-	return PIM_MSDP_ERR_NONE;
+	return mg;
 }
 
 static int pim_msdp_mg_mbr_comp(const void *p1, const void *p2)
@@ -1353,66 +1315,7 @@ static void pim_msdp_mg_mbr_free(struct pim_msdp_mg_mbr *mbr)
 	XFREE(MTYPE_PIM_MSDP_MG_MBR, mbr);
 }
 
-static struct pim_msdp_mg_mbr *pim_msdp_mg_mbr_find(struct pim_instance *pim,
-						    struct in_addr mbr_ip)
-{
-	struct pim_msdp_mg_mbr *mbr;
-	struct listnode *mbr_node;
-
-	if (!pim->msdp.mg) {
-		return NULL;
-	}
-	/* we can move this to a hash but considering that number of peers in
-	 * a mesh-group that seems like bit of an overkill */
-	for (ALL_LIST_ELEMENTS_RO(pim->msdp.mg->mbr_list, mbr_node, mbr)) {
-		if (mbr->mbr_ip.s_addr == mbr_ip.s_addr) {
-			return mbr;
-		}
-	}
-	return mbr;
-}
-
-enum pim_msdp_err pim_msdp_mg_mbr_add(struct pim_instance *pim,
-				      const char *mesh_group_name,
-				      struct in_addr mbr_ip)
-{
-	int rc;
-	struct pim_msdp_mg_mbr *mbr;
-	struct pim_msdp_mg *mg;
-
-	rc = pim_msdp_mg_add(pim, mesh_group_name);
-	if (rc != PIM_MSDP_ERR_NONE) {
-		return rc;
-	}
-
-	mg = pim->msdp.mg;
-	mbr = pim_msdp_mg_mbr_find(pim, mbr_ip);
-	if (mbr) {
-		return PIM_MSDP_ERR_MG_MBR_EXISTS;
-	}
-
-	mbr = XCALLOC(MTYPE_PIM_MSDP_MG_MBR, sizeof(*mbr));
-	mbr->mbr_ip = mbr_ip;
-	listnode_add_sort(mg->mbr_list, mbr);
-
-	/* if valid SIP has been configured add peer session */
-	if (mg->src_ip.s_addr != INADDR_ANY) {
-		pim_msdp_peer_add(pim, mbr_ip, mg->src_ip, mesh_group_name,
-				  &mbr->mp);
-	}
-
-	if (PIM_DEBUG_MSDP_EVENTS) {
-		char ip_str[INET_ADDRSTRLEN];
-		pim_inet4_dump("<mbr?>", mbr->mbr_ip, ip_str, sizeof(ip_str));
-		zlog_debug("MSDP mesh-group %s mbr %s created",
-			   mg->mesh_group_name, ip_str);
-	}
-	++mg->mbr_cnt;
-	return PIM_MSDP_ERR_NONE;
-}
-
-static void pim_msdp_mg_mbr_do_del(struct pim_msdp_mg *mg,
-				   struct pim_msdp_mg_mbr *mbr)
+void pim_msdp_mg_mbr_del(struct pim_msdp_mg *mg, struct pim_msdp_mg_mbr *mbr)
 {
 	/* Delete active peer session if any */
 	if (mbr->mp) {
@@ -1432,34 +1335,10 @@ static void pim_msdp_mg_mbr_do_del(struct pim_msdp_mg *mg,
 	}
 }
 
-enum pim_msdp_err pim_msdp_mg_mbr_del(struct pim_instance *pim,
-				      const char *mesh_group_name,
-				      struct in_addr mbr_ip)
-{
-	struct pim_msdp_mg_mbr *mbr;
-	struct pim_msdp_mg *mg = pim->msdp.mg;
-
-	if (!mg || strcmp(mg->mesh_group_name, mesh_group_name)) {
-		return PIM_MSDP_ERR_NO_MG;
-	}
-
-	mbr = pim_msdp_mg_mbr_find(pim, mbr_ip);
-	if (!mbr) {
-		return PIM_MSDP_ERR_NO_MG_MBR;
-	}
-
-	pim_msdp_mg_mbr_do_del(mg, mbr);
-	/* if there are no references to the mg free it */
-	pim_msdp_mg_free(pim);
-
-	return PIM_MSDP_ERR_NONE;
-}
-
-static void pim_msdp_mg_src_do_del(struct pim_instance *pim)
+static void pim_msdp_src_del(struct pim_msdp_mg *mg)
 {
 	struct pim_msdp_mg_mbr *mbr;
 	struct listnode *mbr_node;
-	struct pim_msdp_mg *mg = pim->msdp.mg;
 
 	/* SIP is being removed - tear down all active peer sessions */
 	for (ALL_LIST_ELEMENTS_RO(mg->mbr_list, mbr_node, mbr)) {
@@ -1474,91 +1353,38 @@ static void pim_msdp_mg_src_do_del(struct pim_instance *pim)
 	}
 }
 
-enum pim_msdp_err pim_msdp_mg_src_del(struct pim_instance *pim,
-				      const char *mesh_group_name)
-{
-	struct pim_msdp_mg *mg = pim->msdp.mg;
-
-	if (!mg || strcmp(mg->mesh_group_name, mesh_group_name)) {
-		return PIM_MSDP_ERR_NO_MG;
-	}
-
-	if (mg->src_ip.s_addr != INADDR_ANY) {
-		mg->src_ip.s_addr = INADDR_ANY;
-		pim_msdp_mg_src_do_del(pim);
-		/* if there are no references to the mg free it */
-		pim_msdp_mg_free(pim);
-	}
-	return PIM_MSDP_ERR_NONE;
-}
-
-enum pim_msdp_err pim_msdp_mg_src_add(struct pim_instance *pim,
-				      const char *mesh_group_name,
-				      struct in_addr src_ip)
-{
-	int rc;
-	struct pim_msdp_mg_mbr *mbr;
-	struct listnode *mbr_node;
-	struct pim_msdp_mg *mg;
-
-	if (src_ip.s_addr == INADDR_ANY) {
-		pim_msdp_mg_src_del(pim, mesh_group_name);
-		return PIM_MSDP_ERR_NONE;
-	}
-
-	rc = pim_msdp_mg_add(pim, mesh_group_name);
-	if (rc != PIM_MSDP_ERR_NONE) {
-		return rc;
-	}
-
-	mg = pim->msdp.mg;
-	if (mg->src_ip.s_addr != INADDR_ANY) {
-		pim_msdp_mg_src_do_del(pim);
-	}
-	mg->src_ip = src_ip;
-
-	for (ALL_LIST_ELEMENTS_RO(mg->mbr_list, mbr_node, mbr)) {
-		pim_msdp_peer_add(pim, mbr->mbr_ip, mg->src_ip, mesh_group_name,
-				  &mbr->mp);
-	}
-
-	if (PIM_DEBUG_MSDP_EVENTS) {
-		char ip_str[INET_ADDRSTRLEN];
-		pim_inet4_dump("<src?>", mg->src_ip, ip_str, sizeof(ip_str));
-		zlog_debug("MSDP mesh-group %s src %s set", mg->mesh_group_name,
-			   ip_str);
-	}
-	return PIM_MSDP_ERR_NONE;
-}
-
 /*********************** MSDP feature APIs *********************************/
 int pim_msdp_config_write(struct pim_instance *pim, struct vty *vty,
 			  const char *spaces)
 {
+	struct pim_msdp_mg *mg;
 	struct listnode *mbrnode;
 	struct pim_msdp_mg_mbr *mbr;
-	struct pim_msdp_mg *mg = pim->msdp.mg;
 	char mbr_str[INET_ADDRSTRLEN];
 	char src_str[INET_ADDRSTRLEN];
 	int count = 0;
 
-	if (!mg) {
+	if (SLIST_EMPTY(&pim->msdp.mglist))
 		return count;
-	}
 
-	if (mg->src_ip.s_addr != INADDR_ANY) {
-		pim_inet4_dump("<src?>", mg->src_ip, src_str, sizeof(src_str));
-		vty_out(vty, "%sip msdp mesh-group %s source %s\n", spaces,
-			mg->mesh_group_name, src_str);
-		++count;
-	}
+	SLIST_FOREACH (mg, &pim->msdp.mglist, mg_entry) {
+		if (mg->src_ip.s_addr != INADDR_ANY) {
+			pim_inet4_dump("<src?>", mg->src_ip, src_str,
+				       sizeof(src_str));
+			vty_out(vty, "%sip msdp mesh-group %s source %s\n",
+				spaces, mg->mesh_group_name, src_str);
+			++count;
+		}
 
-	for (ALL_LIST_ELEMENTS_RO(mg->mbr_list, mbrnode, mbr)) {
-		pim_inet4_dump("<mbr?>", mbr->mbr_ip, mbr_str, sizeof(mbr_str));
-		vty_out(vty, "%sip msdp mesh-group %s member %s\n", spaces,
-			mg->mesh_group_name, mbr_str);
-		++count;
+		for (ALL_LIST_ELEMENTS_RO(mg->mbr_list, mbrnode, mbr)) {
+			pim_inet4_dump("<mbr?>", mbr->mbr_ip, mbr_str,
+				       sizeof(mbr_str));
+			vty_out(vty, "%sip msdp mesh-group %s member %s\n",
+				spaces, mg->mesh_group_name, mbr_str);
+			++count;
+		}
 	}
+
 	return count;
 }
 
@@ -1623,11 +1449,13 @@ void pim_msdp_init(struct pim_instance *pim, struct thread_master *master)
 /* counterpart to MSDP init; XXX: unused currently */
 void pim_msdp_exit(struct pim_instance *pim)
 {
-	pim_msdp_sa_adv_timer_setup(pim, false);
+	struct pim_msdp_mg *mg;
 
-	/* XXX: stop listener and delete all peer sessions */
+	pim_msdp_sa_adv_timer_setup(pim, false);
 
-	pim_msdp_mg_free(pim);
+	/* Stop listener and delete all peer sessions */
+	while ((mg = SLIST_FIRST(&pim->msdp.mglist)) != NULL)
+		pim_msdp_mg_free(pim, &mg);
 
 	if (pim->msdp.peer_hash) {
 		hash_clean(pim->msdp.peer_hash, NULL);
@@ -1653,3 +1481,57 @@ void pim_msdp_exit(struct pim_instance *pim)
 		stream_free(pim->msdp.work_obuf);
 	pim->msdp.work_obuf = NULL;
 }
+
+void pim_msdp_mg_src_add(struct pim_instance *pim, struct pim_msdp_mg *mg,
+			 struct in_addr *ai)
+{
+	struct pim_msdp_mg_mbr *mbr;
+	struct listnode *mbr_node;
+
+	/* Stop all connections and remove data structures. */
+	pim_msdp_src_del(mg);
+
+	/* Set new address. */
+	mg->src_ip = *ai;
+
+	/* No new address, disable everyone. */
+	if (ai->s_addr == INADDR_ANY) {
+		if (PIM_DEBUG_MSDP_EVENTS)
+			zlog_debug("MSDP mesh-group %s src unset",
+				   mg->mesh_group_name);
+		return;
+	}
+
+	/* Create data structures and start TCP connection. */
+	for (ALL_LIST_ELEMENTS_RO(mg->mbr_list, mbr_node, mbr))
+		pim_msdp_peer_add(pim, mbr->mbr_ip, mg->src_ip,
+				  mg->mesh_group_name, &mbr->mp);
+
+	if (PIM_DEBUG_MSDP_EVENTS)
+		zlog_debug("MSDP mesh-group %s src %pI4 set",
+			   mg->mesh_group_name, &mg->src_ip);
+}
+
+struct pim_msdp_mg_mbr *pim_msdp_mg_mbr_add(struct pim_instance *pim,
+					    struct pim_msdp_mg *mg,
+					    struct in_addr *ia)
+{
+	struct pim_msdp_mg_mbr *mbr;
+
+	mbr = XCALLOC(MTYPE_PIM_MSDP_MG_MBR, sizeof(*mbr));
+	mbr->mbr_ip = *ia;
+	listnode_add_sort(mg->mbr_list, mbr);
+
+	/* if valid SIP has been configured add peer session */
+	if (mg->src_ip.s_addr != INADDR_ANY)
+		pim_msdp_peer_add(pim, mbr->mbr_ip, mg->src_ip,
+				  mg->mesh_group_name, &mbr->mp);
+
+	if (PIM_DEBUG_MSDP_EVENTS)
+		zlog_debug("MSDP mesh-group %s mbr %pI4 created",
+			   mg->mesh_group_name, &mbr->mbr_ip);
+
+	++mg->mbr_cnt;
+
+	return mbr;
+}
diff --git a/pimd/pim_msdp.h b/pimd/pim_msdp.h
index 4d01880fb..bb7ee01ad 100644
--- a/pimd/pim_msdp.h
+++ b/pimd/pim_msdp.h
@@ -19,6 +19,8 @@
 #ifndef PIM_MSDP_H
 #define PIM_MSDP_H
 
+#include "lib/openbsd-queue.h"
+
 enum pim_msdp_peer_state {
 	PIM_MSDP_DISABLED,
 	PIM_MSDP_INACTIVE,
@@ -160,8 +162,13 @@ struct pim_msdp_mg {
 	struct in_addr src_ip;
 	uint32_t mbr_cnt;
 	struct list *mbr_list;
+
+	/** Belongs to PIM instance list. */
+	SLIST_ENTRY(pim_msdp_mg) mg_entry;
 };
 
+SLIST_HEAD(pim_mesh_group_list, pim_msdp_mg);
+
 enum pim_msdp_flags {
 	PIM_MSDPF_NONE = 0,
 	PIM_MSDPF_ENABLE = (1 << 0),
@@ -196,8 +203,8 @@ struct pim_msdp {
 
 	struct in_addr originator_id;
 
-	/* currently only one mesh-group is supported - so just stash it here */
-	struct pim_msdp_mg *mg;
+	/** List of mesh groups. */
+	struct pim_mesh_group_list mglist;
 };
 
 #define PIM_MSDP_PEER_READ_ON(mp)                                              \
@@ -246,17 +253,39 @@ bool pim_msdp_peer_rpf_check(struct pim_msdp_peer *mp, struct in_addr rp);
 void pim_msdp_up_join_state_changed(struct pim_instance *pim,
 				    struct pim_upstream *xg_up);
 void pim_msdp_up_del(struct pim_instance *pim, struct prefix_sg *sg);
-enum pim_msdp_err pim_msdp_mg_mbr_add(struct pim_instance *pim,
-				      const char *mesh_group_name,
-				      struct in_addr mbr_ip);
-enum pim_msdp_err pim_msdp_mg_mbr_del(struct pim_instance *pim,
-				      const char *mesh_group_name,
-				      struct in_addr mbr_ip);
-enum pim_msdp_err pim_msdp_mg_src_del(struct pim_instance *pim,
-				      const char *mesh_group_name);
-enum pim_msdp_err pim_msdp_mg_src_add(struct pim_instance *pim,
-				      const char *mesh_group_name,
-				      struct in_addr src_ip);
 enum pim_msdp_err pim_msdp_mg_del(struct pim_instance *pim,
 				  const char *mesh_group_name);
+
+/**
+ * Allocates a new mesh group data structure under PIM instance.
+ */
+struct pim_msdp_mg *pim_msdp_mg_new(struct pim_instance *pim,
+				    const char *mesh_group_name);
+/**
+ * Deallocates mesh group data structure under PIM instance.
+ */
+void pim_msdp_mg_free(struct pim_instance *pim, struct pim_msdp_mg **mgp);
+
+/**
+ * Change the source address of a mesh group peers. It will do the following:
+ * - Close all peers TCP connections
+ * - Recreate peers data structure
+ * - Start TCP connections with new local address.
+ */
+void pim_msdp_mg_src_add(struct pim_instance *pim, struct pim_msdp_mg *mg,
+			 struct in_addr *ai);
+
+/**
+ * Add new peer to mesh group and starts the connection if source address is
+ * configured.
+ */
+struct pim_msdp_mg_mbr *pim_msdp_mg_mbr_add(struct pim_instance *pim,
+					    struct pim_msdp_mg *mg,
+					    struct in_addr *ia);
+
+/**
+ * Stops the connection and removes the peer data structures.
+ */
+void pim_msdp_mg_mbr_del(struct pim_msdp_mg *mg, struct pim_msdp_mg_mbr *mbr);
+
 #endif
diff --git a/pimd/pim_nb.c b/pimd/pim_nb.c
index 37c539883..ea53f1ef1 100644
--- a/pimd/pim_nb.c
+++ b/pimd/pim_nb.c
@@ -118,31 +118,24 @@ const struct frr_yang_module_info frr_pim_info = {
 			}
 		},
 		{
-			.xpath = "/frr-routing:routing/control-plane-protocols/control-plane-protocol/frr-pim:pim/address-family/msdp-mesh-group",
+			.xpath = "/frr-routing:routing/control-plane-protocols/control-plane-protocol/frr-pim:pim/address-family/msdp-mesh-groups",
 			.cbs = {
-				.create = routing_control_plane_protocols_control_plane_protocol_pim_address_family_msdp_mesh_group_create,
-				.destroy = routing_control_plane_protocols_control_plane_protocol_pim_address_family_msdp_mesh_group_destroy,
+				.create = pim_msdp_mesh_group_create,
+				.destroy = pim_msdp_mesh_group_destroy,
 			}
 		},
 		{
-			.xpath = "/frr-routing:routing/control-plane-protocols/control-plane-protocol/frr-pim:pim/address-family/msdp-mesh-group/mesh-group-name",
+			.xpath = "/frr-routing:routing/control-plane-protocols/control-plane-protocol/frr-pim:pim/address-family/msdp-mesh-groups/source",
 			.cbs = {
-				.modify = routing_control_plane_protocols_control_plane_protocol_pim_address_family_msdp_mesh_group_mesh_group_name_modify,
-				.destroy = routing_control_plane_protocols_control_plane_protocol_pim_address_family_msdp_mesh_group_mesh_group_name_destroy,
+				.modify = pim_msdp_mesh_group_source_modify,
+				.destroy = pim_msdp_mesh_group_source_destroy,
 			}
 		},
 		{
-			.xpath = "/frr-routing:routing/control-plane-protocols/control-plane-protocol/frr-pim:pim/address-family/msdp-mesh-group/member-ip",
+			.xpath = "/frr-routing:routing/control-plane-protocols/control-plane-protocol/frr-pim:pim/address-family/msdp-mesh-groups/members",
 			.cbs = {
-				.create = routing_control_plane_protocols_control_plane_protocol_pim_address_family_msdp_mesh_group_member_ip_create,
-				.destroy = routing_control_plane_protocols_control_plane_protocol_pim_address_family_msdp_mesh_group_member_ip_destroy,
-			}
-		},
-		{
-			.xpath = "/frr-routing:routing/control-plane-protocols/control-plane-protocol/frr-pim:pim/address-family/msdp-mesh-group/source-ip",
-			.cbs = {
-				.modify = routing_control_plane_protocols_control_plane_protocol_pim_address_family_msdp_mesh_group_source_ip_modify,
-				.destroy = routing_control_plane_protocols_control_plane_protocol_pim_address_family_msdp_mesh_group_source_ip_destroy,
+				.create = pim_msdp_mesh_group_members_create,
+				.destroy = pim_msdp_mesh_group_members_destroy,
 			}
 		},
 		{
diff --git a/pimd/pim_nb.h b/pimd/pim_nb.h
index 440384e45..1959b403f 100644
--- a/pimd/pim_nb.h
+++ b/pimd/pim_nb.h
@@ -60,22 +60,12 @@ int routing_control_plane_protocols_control_plane_protocol_pim_address_family_ss
 	struct nb_cb_create_args *args);
 int routing_control_plane_protocols_control_plane_protocol_pim_address_family_ssm_pingd_source_ip_destroy(
 	struct nb_cb_destroy_args *args);
-int routing_control_plane_protocols_control_plane_protocol_pim_address_family_msdp_mesh_group_create(
-	struct nb_cb_create_args *args);
-int routing_control_plane_protocols_control_plane_protocol_pim_address_family_msdp_mesh_group_destroy(
-	struct nb_cb_destroy_args *args);
-int routing_control_plane_protocols_control_plane_protocol_pim_address_family_msdp_mesh_group_mesh_group_name_modify(
-	struct nb_cb_modify_args *args);
-int routing_control_plane_protocols_control_plane_protocol_pim_address_family_msdp_mesh_group_mesh_group_name_destroy(
-	struct nb_cb_destroy_args *args);
-int routing_control_plane_protocols_control_plane_protocol_pim_address_family_msdp_mesh_group_member_ip_create(
-	struct nb_cb_create_args *args);
-int routing_control_plane_protocols_control_plane_protocol_pim_address_family_msdp_mesh_group_member_ip_destroy(
-	struct nb_cb_destroy_args *args);
-int routing_control_plane_protocols_control_plane_protocol_pim_address_family_msdp_mesh_group_source_ip_modify(
-	struct nb_cb_modify_args *args);
-int routing_control_plane_protocols_control_plane_protocol_pim_address_family_msdp_mesh_group_source_ip_destroy(
-	struct nb_cb_destroy_args *args);
+int pim_msdp_mesh_group_create(struct nb_cb_create_args *args);
+int pim_msdp_mesh_group_destroy(struct nb_cb_destroy_args *args);
+int pim_msdp_mesh_group_members_create(struct nb_cb_create_args *args);
+int pim_msdp_mesh_group_members_destroy(struct nb_cb_destroy_args *args);
+int pim_msdp_mesh_group_source_modify(struct nb_cb_modify_args *args);
+int pim_msdp_mesh_group_source_destroy(struct nb_cb_destroy_args *args);
 int routing_control_plane_protocols_control_plane_protocol_pim_address_family_msdp_peer_create(
 	struct nb_cb_create_args *args);
 int routing_control_plane_protocols_control_plane_protocol_pim_address_family_msdp_peer_destroy(
diff --git a/pimd/pim_nb_config.c b/pimd/pim_nb_config.c
index 11e8da3b8..b70656ea7 100644
--- a/pimd/pim_nb_config.c
+++ b/pimd/pim_nb_config.c
@@ -243,147 +243,6 @@ static int pim_ssm_cmd_worker(struct pim_instance *pim, const char *plist,
 	return ret;
 }
 
-static int ip_no_msdp_mesh_group_cmd_worker(struct pim_instance *pim,
-		const char *mg,
-		char *errmsg, size_t errmsg_len)
-{
-	enum pim_msdp_err result;
-
-	result = pim_msdp_mg_del(pim, mg);
-
-	switch (result) {
-	case PIM_MSDP_ERR_NONE:
-		break;
-	case PIM_MSDP_ERR_NO_MG:
-		snprintf(errmsg, errmsg_len,
-			 "%% mesh-group does not exist");
-		break;
-	default:
-		snprintf(errmsg, errmsg_len,
-			 "mesh-group source del failed");
-	}
-
-	return result ? NB_ERR : NB_OK;
-}
-
-static int ip_msdp_mesh_group_member_cmd_worker(struct pim_instance *pim,
-		const char *mg,
-		struct in_addr mbr_ip,
-		char *errmsg, size_t errmsg_len)
-{
-	enum pim_msdp_err result;
-	int ret = NB_OK;
-
-	result = pim_msdp_mg_mbr_add(pim, mg, mbr_ip);
-
-	switch (result) {
-	case PIM_MSDP_ERR_NONE:
-		break;
-	case PIM_MSDP_ERR_OOM:
-		ret = NB_ERR;
-		snprintf(errmsg, errmsg_len,
-			 "%% Out of memory");
-		break;
-	case PIM_MSDP_ERR_MG_MBR_EXISTS:
-		ret = NB_ERR;
-		snprintf(errmsg, errmsg_len,
-			 "%% mesh-group member exists");
-		break;
-	case PIM_MSDP_ERR_MAX_MESH_GROUPS:
-		ret = NB_ERR;
-		snprintf(errmsg, errmsg_len,
-			 "%% Only one mesh-group allowed currently");
-		break;
-	default:
-		ret = NB_ERR;
-		snprintf(errmsg, errmsg_len,
-			 "%% member add failed");
-	}
-
-	return ret;
-}
-
-static int ip_no_msdp_mesh_group_member_cmd_worker(struct pim_instance *pim,
-		const char *mg,
-		struct in_addr mbr_ip,
-		char *errmsg,
-		size_t errmsg_len)
-{
-	enum pim_msdp_err result;
-
-	result = pim_msdp_mg_mbr_del(pim, mg, mbr_ip);
-
-	switch (result) {
-	case PIM_MSDP_ERR_NONE:
-		break;
-	case PIM_MSDP_ERR_NO_MG:
-		snprintf(errmsg, errmsg_len,
-			 "%% mesh-group does not exist");
-		break;
-	case PIM_MSDP_ERR_NO_MG_MBR:
-		snprintf(errmsg, errmsg_len,
-			 "%% mesh-group member does not exist");
-		break;
-	default:
-		snprintf(errmsg, errmsg_len,
-			 "%% mesh-group member del failed");
-	}
-
-	return result ? NB_ERR : NB_OK;
-}
-
-static int ip_msdp_mesh_group_source_cmd_worker(struct pim_instance *pim,
-		const char *mg,
-		struct in_addr src_ip,
-		char *errmsg, size_t errmsg_len)
-{
-	enum pim_msdp_err result;
-
-	result = pim_msdp_mg_src_add(pim, mg, src_ip);
-
-	switch (result) {
-	case PIM_MSDP_ERR_NONE:
-		break;
-	case PIM_MSDP_ERR_OOM:
-		snprintf(errmsg, errmsg_len,
-			 "%% Out of memory");
-		break;
-	case PIM_MSDP_ERR_MAX_MESH_GROUPS:
-		snprintf(errmsg, errmsg_len,
-			 "%% Only one mesh-group allowed currently");
-		break;
-	default:
-		snprintf(errmsg, errmsg_len,
-			 "%% source add failed");
-	}
-
-	return result ? NB_ERR : NB_OK;
-}
-
-static int ip_no_msdp_mesh_group_source_cmd_worker(struct pim_instance *pim,
-		const char *mg,
-		char *errmsg,
-		size_t errmsg_len)
-{
-	enum pim_msdp_err result;
-
-	result = pim_msdp_mg_src_del(pim, mg);
-
-	switch (result) {
-	case PIM_MSDP_ERR_NONE:
-		break;
-	case PIM_MSDP_ERR_NO_MG:
-		snprintf(errmsg, errmsg_len,
-			 "%% mesh-group does not exist");
-		break;
-	default:
-		snprintf(errmsg, errmsg_len,
-			 "%% mesh-group source del failed");
-	}
-
-	return result ? NB_ERR : NB_OK;
-}
-
 static int ip_msdp_peer_cmd_worker(struct pim_instance *pim,
 		struct in_addr peer_addr,
 		struct in_addr local_addr,
@@ -1146,29 +1005,13 @@ int routing_control_plane_protocols_control_plane_protocol_pim_address_family_ss
 }
 
 /*
- * XPath: /frr-routing:routing/control-plane-protocols/control-plane-protocol/frr-pim:pim/address-family/msdp-mesh-group
+ * XPath:
+ * /frr-routing:routing/control-plane-protocols/control-plane-protocol/frr-pim:pim/address-family/msdp-mesh-groups
  */
-int routing_control_plane_protocols_control_plane_protocol_pim_address_family_msdp_mesh_group_create(
-	struct nb_cb_create_args *args)
-{
-	switch (args->event) {
-	case NB_EV_VALIDATE:
-	case NB_EV_PREPARE:
-	case NB_EV_ABORT:
-	case NB_EV_APPLY:
-		break;
-	}
-
-	return NB_OK;
-}
-
-int routing_control_plane_protocols_control_plane_protocol_pim_address_family_msdp_mesh_group_destroy(
-	struct nb_cb_destroy_args *args)
+int pim_msdp_mesh_group_create(struct nb_cb_create_args *args)
 {
+	struct pim_msdp_mg *mg;
 	struct vrf *vrf;
-	struct pim_instance *pim;
-	const char *mesh_group_name;
-	int result;
 
 	switch (args->event) {
 	case NB_EV_VALIDATE:
@@ -1177,67 +1020,29 @@ int routing_control_plane_protocols_control_plane_protocol_pim_address_family_ms
 		break;
 	case NB_EV_APPLY:
 		vrf = nb_running_get_entry(args->dnode, NULL, true);
-		pim = vrf->info;
-		mesh_group_name = yang_dnode_get_string(args->dnode, "mesh-group-name");
-
-		result = ip_no_msdp_mesh_group_cmd_worker(pim, mesh_group_name,
-				args->errmsg,
-				args->errmsg_len);
-
-		if (result != PIM_MSDP_ERR_NONE)
-			return NB_ERR_INCONSISTENCY;
-
+		mg = pim_msdp_mg_new(vrf->info, yang_dnode_get_string(
+							args->dnode, "./name"));
+		nb_running_set_entry(args->dnode, mg);
 		break;
 	}
 
 	return NB_OK;
 }
 
-/*
- * XPath: /frr-routing:routing/control-plane-protocols/control-plane-protocol/frr-pim:pim/address-family/msdp-mesh-group/mesh-group-name
- */
-int routing_control_plane_protocols_control_plane_protocol_pim_address_family_msdp_mesh_group_mesh_group_name_modify(
-	struct nb_cb_modify_args *args)
+int pim_msdp_mesh_group_destroy(struct nb_cb_destroy_args *args)
 {
-	const char *mesh_group_name;
-	const char *mesh_group_name_old;
-	char xpath[XPATH_MAXLEN];
+	struct pim_msdp_mg *mg;
+	struct vrf *vrf;
 
 	switch (args->event) {
 	case NB_EV_VALIDATE:
-		mesh_group_name = yang_dnode_get_string(args->dnode, ".");
-		yang_dnode_get_path(args->dnode, xpath, sizeof(xpath));
-
-		if (yang_dnode_exists(running_config->dnode, xpath) == false)
-			break;
-
-		mesh_group_name_old = yang_dnode_get_string(
-					running_config->dnode,
-					xpath);
-		if (strcmp(mesh_group_name, mesh_group_name_old)) {
-			/* currently only one mesh-group can exist at a time */
-			snprintf(args->errmsg, args->errmsg_len,
-				 "Only one mesh-group allowed currently");
-			return NB_ERR_VALIDATION;
-		}
-		break;
 	case NB_EV_PREPARE:
 	case NB_EV_ABORT:
-	case NB_EV_APPLY:
 		break;
-	}
-
-	return NB_OK;
-}
-
-int routing_control_plane_protocols_control_plane_protocol_pim_address_family_msdp_mesh_group_mesh_group_name_destroy(
-	struct nb_cb_destroy_args *args)
-{
-	switch (args->event) {
-	case NB_EV_VALIDATE:
-	case NB_EV_PREPARE:
-	case NB_EV_ABORT:
 	case NB_EV_APPLY:
+		mg = nb_running_unset_entry(args->dnode);
+		vrf = nb_running_get_entry(args->dnode, NULL, true);
+		pim_msdp_mg_free(vrf->info, &mg);
 		break;
 	}
 
@@ -1245,16 +1050,15 @@ int routing_control_plane_protocols_control_plane_protocol_pim_address_family_ms
 }
 
 /*
- * XPath: /frr-routing:routing/control-plane-protocols/control-plane-protocol/frr-pim:pim/address-family/msdp-mesh-group/member-ip
+ * XPath:
+ * /frr-routing:routing/control-plane-protocols/control-plane-protocol/frr-pim:pim/address-family/msdp-mesh-groups/source
  */
-int routing_control_plane_protocols_control_plane_protocol_pim_address_family_msdp_mesh_group_member_ip_create(
-	struct nb_cb_create_args *args)
+int pim_msdp_mesh_group_source_modify(struct nb_cb_modify_args *args)
 {
+	const struct lyd_node *vrf_dnode;
+	struct pim_msdp_mg *mg;
 	struct vrf *vrf;
-	struct pim_instance *pim;
-	const char *mesh_group_name;
-	struct ipaddr mbr_ip;
-	enum pim_msdp_err result;
+	struct ipaddr ip;
 
 	switch (args->event) {
 	case NB_EV_VALIDATE:
@@ -1262,33 +1066,24 @@ int routing_control_plane_protocols_control_plane_protocol_pim_address_family_ms
 	case NB_EV_ABORT:
 		break;
 	case NB_EV_APPLY:
-		vrf = nb_running_get_entry(args->dnode, NULL, true);
-		pim = vrf->info;
-		mesh_group_name = yang_dnode_get_string(args->dnode,
-				"../mesh-group-name");
-		yang_dnode_get_ip(&mbr_ip, args->dnode, NULL);
-
-		result = ip_msdp_mesh_group_member_cmd_worker(
-				pim, mesh_group_name, mbr_ip.ip._v4_addr,
-				args->errmsg, args->errmsg_len);
-
-		if (result != PIM_MSDP_ERR_NONE)
-			return NB_ERR_INCONSISTENCY;
+		mg = nb_running_get_entry(args->dnode, NULL, true);
+		vrf_dnode =
+			yang_dnode_get_parent(args->dnode, "address-family");
+		vrf = nb_running_get_entry(vrf_dnode, "../../", true);
+		yang_dnode_get_ip(&ip, args->dnode, NULL);
 
+		pim_msdp_mg_src_add(vrf->info, mg, &ip.ip._v4_addr);
 		break;
 	}
-
 	return NB_OK;
 }
 
-int routing_control_plane_protocols_control_plane_protocol_pim_address_family_msdp_mesh_group_member_ip_destroy(
-	struct nb_cb_destroy_args *args)
+int pim_msdp_mesh_group_source_destroy(struct nb_cb_destroy_args *args)
 {
+	const struct lyd_node *vrf_dnode;
+	struct pim_msdp_mg *mg;
 	struct vrf *vrf;
-	struct pim_instance *pim;
-	const char *mesh_group_name;
-	struct ipaddr mbr_ip;
-	enum pim_msdp_err result;
+	struct in_addr addr;
 
 	switch (args->event) {
 	case NB_EV_VALIDATE:
@@ -1296,36 +1091,30 @@ int routing_control_plane_protocols_control_plane_protocol_pim_address_family_ms
 	case NB_EV_ABORT:
 		break;
 	case NB_EV_APPLY:
-		vrf = nb_running_get_entry(args->dnode, NULL, true);
-		pim = vrf->info;
-		mesh_group_name = yang_dnode_get_string(args->dnode,
-				"../mesh-group-name");
-		yang_dnode_get_ip(&mbr_ip, args->dnode, NULL);
-
-		result = ip_no_msdp_mesh_group_member_cmd_worker(
-				pim, mesh_group_name, mbr_ip.ip._v4_addr,
-				args->errmsg, args->errmsg_len);
-
-		if (result != PIM_MSDP_ERR_NONE)
-			return NB_ERR_INCONSISTENCY;
+		mg = nb_running_get_entry(args->dnode, NULL, true);
+		vrf_dnode =
+			yang_dnode_get_parent(args->dnode, "address-family");
+		vrf = nb_running_get_entry(vrf_dnode, "../../", true);
 
+		addr.s_addr = INADDR_ANY;
+		pim_msdp_mg_src_add(vrf->info, mg, &addr);
 		break;
 	}
-
 	return NB_OK;
 }
 
+
 /*
- * XPath: /frr-routing:routing/control-plane-protocols/control-plane-protocol/frr-pim:pim/address-family/msdp-mesh-group/source-ip
+ * XPath:
+ * /frr-routing:routing/control-plane-protocols/control-plane-protocol/frr-pim:pim/address-family/msdp-mesh-groups/members
  */
-int routing_control_plane_protocols_control_plane_protocol_pim_address_family_msdp_mesh_group_source_ip_modify(
-	struct nb_cb_modify_args *args)
+int pim_msdp_mesh_group_members_create(struct nb_cb_create_args *args)
 {
+	const struct lyd_node *vrf_dnode;
+	struct pim_msdp_mg_mbr *mbr;
+	struct pim_msdp_mg *mg;
 	struct vrf *vrf;
-	struct pim_instance *pim;
-	const char *mesh_group_name;
-	struct ipaddr src_ip;
-	enum pim_msdp_err result;
+	struct ipaddr ip;
 
 	switch (args->event) {
 	case NB_EV_VALIDATE:
@@ -1333,31 +1122,24 @@ int routing_control_plane_protocols_control_plane_protocol_pim_address_family_ms
 	case NB_EV_ABORT:
 		break;
 	case NB_EV_APPLY:
-		vrf = nb_running_get_entry(args->dnode, NULL, true);
-		pim = vrf->info;
-		mesh_group_name = yang_dnode_get_string(args->dnode,
-				"../mesh-group-name");
-		yang_dnode_get_ip(&src_ip, args->dnode, NULL);
-
-		result = ip_msdp_mesh_group_source_cmd_worker(
-				pim, mesh_group_name, src_ip.ip._v4_addr,
-				args->errmsg, args->errmsg_len);
-
-		if (result != PIM_MSDP_ERR_NONE)
-			return NB_ERR_INCONSISTENCY;
+		mg = nb_running_get_entry(args->dnode, NULL, true);
+		vrf_dnode =
+			yang_dnode_get_parent(args->dnode, "address-family");
+		vrf = nb_running_get_entry(vrf_dnode, "../../", true);
+		yang_dnode_get_ip(&ip, args->dnode, "address");
 
+		mbr = pim_msdp_mg_mbr_add(vrf->info, mg, &ip.ip._v4_addr);
+		nb_running_set_entry(args->dnode, mbr);
 		break;
 	}
+
 	return NB_OK;
 }
 
-int routing_control_plane_protocols_control_plane_protocol_pim_address_family_msdp_mesh_group_source_ip_destroy(
-	struct nb_cb_destroy_args *args)
+int pim_msdp_mesh_group_members_destroy(struct nb_cb_destroy_args *args)
 {
-	struct vrf *vrf;
-	struct pim_instance *pim;
-	const char *mesh_group_name;
-	enum pim_msdp_err result;
+	struct pim_msdp_mg_mbr *mbr;
+	struct pim_msdp_mg *mg;
 
 	switch (args->event) {
 	case NB_EV_VALIDATE:
@@ -1365,20 +1147,13 @@ int routing_control_plane_protocols_control_plane_protocol_pim_address_family_ms
 	case NB_EV_ABORT:
 		break;
 	case NB_EV_APPLY:
-		vrf = nb_running_get_entry(args->dnode, NULL, true);
-		pim = vrf->info;
-		mesh_group_name = yang_dnode_get_string(args->dnode,
-				"../mesh-group-name");
-
-		result = ip_no_msdp_mesh_group_source_cmd_worker(
-				pim, mesh_group_name, args->errmsg,
-				args->errmsg_len);
-
-		if (result != PIM_MSDP_ERR_NONE)
-			return NB_ERR_INCONSISTENCY;
+		mbr = nb_running_get_entry(args->dnode, NULL, true);
+		mg = nb_running_get_entry(args->dnode, "../", true);
 
+		pim_msdp_mg_mbr_del(mg, mbr);
 		break;
 	}
+
 	return NB_OK;
 }
 
diff --git a/tests/topotests/lib/mcast-tester.py b/tests/topotests/lib/mcast-tester.py
new file mode 100755
index 000000000..07e4ab877
--- /dev/null
+++ b/tests/topotests/lib/mcast-tester.py
@@ -0,0 +1,129 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2021 by
+# Network Device Education Foundation, Inc. ("NetDEF")
+#
+# Permission to use, copy, modify, and/or distribute this software for any
+# purpose with or without fee is hereby granted, provided that the above
+# copyright notice and this permission notice appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+# REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+# AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+# INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+# LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+# OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+# PERFORMANCE OF THIS SOFTWARE.
+
+"""
+Subscribe to a multicast group so that the kernel sends an IGMP JOIN
+for the multicast group we subscribed to.
+"""
+
+import argparse
+import os
+import json
+import socket
+import subprocess
+import struct
+import sys
+import time
+
+#
+# Functions
+#
+def interface_name_to_index(name):
+    "Gets the interface index using its name. Returns None on failure."
+    interfaces = json.loads(
+        subprocess.check_output('ip -j link show', shell=True))
+
+    for interface in interfaces:
+        if interface['ifname'] == name:
+            return interface['ifindex']
+
+    return None
+
+
+def multicast_join(sock, ifindex, group, port):
+    "Joins a multicast group."
+    mreq = struct.pack(
+        "=4sLL", socket.inet_aton(args.group), socket.INADDR_ANY, ifindex
+    )
+
+    sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+    sock.bind((group, port))
+    sock.setsockopt(socket.IPPROTO_IP, socket.IP_ADD_MEMBERSHIP, mreq)
+
+
+#
+# Main code.
+#
+parser = argparse.ArgumentParser(description="Multicast RX utility")
+parser.add_argument('socket', help='Point to topotest UNIX socket')
+parser.add_argument('group', help='Multicast IP')
+parser.add_argument('interface', help='Interface name')
+parser.add_argument(
+    '--send',
+    help='Transmit instead of join with interval (defaults to 0.7 sec)',
+    type=float, default=0)
+args = parser.parse_args()
+
+ttl = 16
+port = 1000
+
+# Get interface index/validate.
+ifindex = interface_name_to_index(args.interface)
+if ifindex is None:
+    sys.stderr.write('Interface {} does not exists\n'.format(args.interface))
+    sys.exit(1)
+
+# We need root privileges to set up multicast.
+if os.geteuid() != 0:
+    sys.stderr.write("ERROR: You must have root privileges\n")
+    sys.exit(1)
+
+# Wait for topotest to synchronize with us.
+toposock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM, 0)
+while True:
+    try:
+        toposock.connect(args.socket)
+        break
+    except ConnectionRefusedError:
+        time.sleep(1)
+        continue
+
+msock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+if args.send > 0:
+    # Prepare multicast bit in that interface.
+    msock.setsockopt(
+        socket.SOL_SOCKET, 25,
+        struct.pack("%ds" % len(args.interface),
+                    args.interface.encode('utf-8')))
+    # Set packets TTL.
+    msock.setsockopt(
+        socket.IPPROTO_IP, socket.IP_MULTICAST_TTL, struct.pack("b", ttl))
+    # Block to ensure packet send.
+    msock.setblocking(True)
+    # Set topotest socket non blocking so we can multiplex the main loop.
+    toposock.setblocking(False)
+else:
+    multicast_join(msock, ifindex, args.group, port)
+
+counter = 0
+while True:
+    if args.send > 0:
+        msock.sendto(b"test %d" % counter, (args.group, port))
+        counter += 1
+        time.sleep(args.send)
+
+    try:
+        data = toposock.recv(1)
+        if data == b'':
+            print(' -> Connection closed')
+            break
+    except BlockingIOError:
+        continue
+
+msock.close()
+
+sys.exit(0)
diff --git a/tests/topotests/lib/topogen.py b/tests/topotests/lib/topogen.py
index 553f2bc6c..4b0f07eb1 100644
--- a/tests/topotests/lib/topogen.py
+++ b/tests/topotests/lib/topogen.py
@@ -222,6 +222,22 @@ class Topogen(object):
         self.peern += 1
         return self.gears[name]
 
+    def add_host(self, name, ip, defaultRoute):
+        """
+        Adds a new host to the topology. This function has the following
+        parameters:
+        * `ip`: the peer address (e.g. '1.2.3.4/24')
+        * `defaultRoute`: the peer default route (e.g. 'via 1.2.3.1')
+        """
+        if name is None:
+            name = "host{}".format(self.peern)
+        if name in self.gears:
+            raise KeyError("host already exists")
+
+        self.gears[name] = TopoHost(self, name, ip=ip, defaultRoute=defaultRoute)
+        self.peern += 1
+        return self.gears[name]
+
     def add_link(self, node1, node2, ifname1=None, ifname2=None):
         """
         Creates a connection between node1 and node2. The nodes can be the
diff --git a/tests/topotests/msdp_mesh_topo1/__init__.py b/tests/topotests/msdp_mesh_topo1/__init__.py
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/tests/topotests/msdp_mesh_topo1/__init__.py
diff --git a/tests/topotests/msdp_mesh_topo1/r1/bgpd.conf b/tests/topotests/msdp_mesh_topo1/r1/bgpd.conf
new file mode 100644
index 000000000..953d90aa0
--- /dev/null
+++ b/tests/topotests/msdp_mesh_topo1/r1/bgpd.conf
@@ -0,0 +1,7 @@
+router bgp 65000
+ neighbor 10.254.254.2 remote-as 65000
+ neighbor 10.254.254.2 update-source 10.254.254.1
+ address-family ipv4 unicast
+  redistribute connected
+ exit-address-family
+!
diff --git a/tests/topotests/msdp_mesh_topo1/r1/ospfd.conf b/tests/topotests/msdp_mesh_topo1/r1/ospfd.conf
new file mode 100644
index 000000000..c1adbd544
--- /dev/null
+++ b/tests/topotests/msdp_mesh_topo1/r1/ospfd.conf
@@ -0,0 +1,8 @@
+interface r1-eth0
+ ip ospf hello-interval 2
+ ip ospf dead-interval 10
+!
+router ospf
+ network 192.168.1.0/24 area 0.0.0.0
+ redistribute connected
+!
diff --git a/tests/topotests/msdp_mesh_topo1/r1/pimd.conf b/tests/topotests/msdp_mesh_topo1/r1/pimd.conf
new file mode 100644
index 000000000..49341efa5
--- /dev/null
+++ b/tests/topotests/msdp_mesh_topo1/r1/pimd.conf
@@ -0,0 +1,15 @@
+interface lo
+ ip pim
+ ip pim use-source 10.254.254.1
+!
+interface r1-eth0
+ ip pim
+!
+interface r1-eth1
+ ip pim
+ ip igmp
+!
+ip pim rp 10.254.254.1
+ip msdp mesh-group mg-1 source 10.254.254.1
+ip msdp mesh-group mg-1 member 10.254.254.2
+ip msdp mesh-group mg-1 member 10.254.254.3
diff --git a/tests/topotests/msdp_mesh_topo1/r1/zebra.conf b/tests/topotests/msdp_mesh_topo1/r1/zebra.conf
new file mode 100644
index 000000000..42c850f00
--- /dev/null
+++ b/tests/topotests/msdp_mesh_topo1/r1/zebra.conf
@@ -0,0 +1,11 @@
+ip forwarding
+!
+interface lo
+ ip address 10.254.254.1/32
+!
+interface r1-eth0
+ ip address 192.168.1.2/24
+!
+interface r1-eth1
+ ip address 192.168.10.1/24
+!
diff --git a/tests/topotests/msdp_mesh_topo1/r2/bgpd.conf b/tests/topotests/msdp_mesh_topo1/r2/bgpd.conf
new file mode 100644
index 000000000..f442efc60
--- /dev/null
+++ b/tests/topotests/msdp_mesh_topo1/r2/bgpd.conf
@@ -0,0 +1,10 @@
+router bgp 65000
+ neighbor pg-1 peer-group
+ neighbor pg-1 update-source 10.254.254.1
+ neighbor pg-1 remote-as 65000
+ neighbor 10.254.254.1 peer-group pg-1
+ neighbor 10.254.254.3 peer-group pg-1
+ address-family ipv4 unicast
+  redistribute connected
+ exit-address-family
+!
diff --git a/tests/topotests/msdp_mesh_topo1/r2/ospfd.conf b/tests/topotests/msdp_mesh_topo1/r2/ospfd.conf
new file mode 100644
index 000000000..9e9ac5fb2
--- /dev/null
+++ b/tests/topotests/msdp_mesh_topo1/r2/ospfd.conf
@@ -0,0 +1,13 @@
+interface r2-eth0
+ ip ospf hello-interval 2
+ ip ospf dead-interval 10
+!
+interface r2-eth1
+ ip ospf hello-interval 2
+ ip ospf dead-interval 10
+!
+router ospf
+ network 192.168.1.0/24 area 0.0.0.0
+ network 192.168.2.0/24 area 0.0.0.0
+ redistribute connected
+!
diff --git a/tests/topotests/msdp_mesh_topo1/r2/pimd.conf b/tests/topotests/msdp_mesh_topo1/r2/pimd.conf
new file mode 100644
index 000000000..9005263ed
--- /dev/null
+++ b/tests/topotests/msdp_mesh_topo1/r2/pimd.conf
@@ -0,0 +1,14 @@
+interface lo
+ ip pim
+ ip pim use-source 10.254.254.2
+!
+interface r2-eth0
+ ip pim
+!
+interface r2-eth1
+ ip pim
+!
+ip pim rp 10.254.254.2
+ip msdp mesh-group mg-1 source 10.254.254.2
+ip msdp mesh-group mg-1 member 10.254.254.1
+ip msdp mesh-group mg-1 member 10.254.254.3
diff --git a/tests/topotests/msdp_mesh_topo1/r2/zebra.conf b/tests/topotests/msdp_mesh_topo1/r2/zebra.conf
new file mode 100644
index 000000000..6b2619421
--- /dev/null
+++ b/tests/topotests/msdp_mesh_topo1/r2/zebra.conf
@@ -0,0 +1,11 @@
+ip forwarding
+!
+interface lo
+ ip address 10.254.254.2/32
+!
+interface r2-eth0
+ ip address 192.168.1.1/24
+!
+interface r2-eth1
+ ip address 192.168.2.1/24
+!
diff --git a/tests/topotests/msdp_mesh_topo1/r3/bgpd.conf b/tests/topotests/msdp_mesh_topo1/r3/bgpd.conf
new file mode 100644
index 000000000..6c3f89ad9
--- /dev/null
+++ b/tests/topotests/msdp_mesh_topo1/r3/bgpd.conf
@@ -0,0 +1,7 @@
+router bgp 65000
+ neighbor 192.168.2.1 remote-as 65000
+ neighbor 192.168.2.1 update-source 10.254.254.3
+ address-family ipv4 unicast
+  redistribute connected
+ exit-address-family
+!
diff --git a/tests/topotests/msdp_mesh_topo1/r3/ospfd.conf b/tests/topotests/msdp_mesh_topo1/r3/ospfd.conf
new file mode 100644
index 000000000..7b7b1abe6
--- /dev/null
+++ b/tests/topotests/msdp_mesh_topo1/r3/ospfd.conf
@@ -0,0 +1,8 @@
+interface r3-eth0
+ ip ospf hello-interval 2
+ ip ospf dead-interval 10
+!
+router ospf
+ network 192.168.2.0/24 area 0.0.0.0
+ redistribute connected
+!
diff --git a/tests/topotests/msdp_mesh_topo1/r3/pimd.conf b/tests/topotests/msdp_mesh_topo1/r3/pimd.conf
new file mode 100644
index 000000000..30e114856
--- /dev/null
+++ b/tests/topotests/msdp_mesh_topo1/r3/pimd.conf
@@ -0,0 +1,15 @@
+interface lo
+ ip pim
+ ip pim use-source 10.254.254.3
+!
+interface r3-eth0
+ ip pim
+!
+interface r3-eth1
+ ip pim
+ ip igmp
+!
+ip pim rp 10.254.254.3
+ip msdp mesh-group mg-1 source 10.254.254.3
+ip msdp mesh-group mg-1 member 10.254.254.1
+ip msdp mesh-group mg-1 member 10.254.254.2
diff --git a/tests/topotests/msdp_mesh_topo1/r3/zebra.conf b/tests/topotests/msdp_mesh_topo1/r3/zebra.conf
new file mode 100644
index 000000000..a8a15f3c0
--- /dev/null
+++ b/tests/topotests/msdp_mesh_topo1/r3/zebra.conf
@@ -0,0 +1,11 @@
+ip forwarding
+!
+interface lo
+ ip address 10.254.254.3/32
+!
+interface r3-eth0
+ ip address 192.168.2.2/24
+!
+interface r3-eth1
+ ip address 192.168.30.1/24
+!
diff --git a/tests/topotests/msdp_mesh_topo1/test_msdp_mesh_topo1.dot b/tests/topotests/msdp_mesh_topo1/test_msdp_mesh_topo1.dot
new file mode 100644
index 000000000..8792e2c7b
--- /dev/null
+++ b/tests/topotests/msdp_mesh_topo1/test_msdp_mesh_topo1.dot
@@ -0,0 +1,88 @@
+## Color coding:
+#########################
+##  Main FRR: #f08080  red
+##  Switches: #d0e0d0  gray
+##  RIP:      #19e3d9  Cyan
+##  RIPng:    #fcb314  dark yellow
+##  OSPFv2:   #32b835  Green
+##  OSPFv3:   #19e3d9  Cyan
+##  ISIS IPv4 #fcb314  dark yellow
+##  ISIS IPv6 #9a81ec  purple
+##  BGP IPv4  #eee3d3  beige
+##  BGP IPv6  #fdff00  yellow
+##### Colors (see http://www.color-hex.com/)
+
+graph template {
+  label="msdp_mesh_topo1";
+
+  # Routers
+  r1 [
+    shape=doubleoctagon,
+    label="r1",
+    fillcolor="#f08080",
+    style=filled,
+  ];
+  r2 [
+    shape=doubleoctagon
+    label="r2",
+    fillcolor="#f08080",
+    style=filled,
+  ];
+  r3 [
+    shape=doubleoctagon
+    label="r3",
+    fillcolor="#f08080",
+    style=filled,
+  ];
+  h1 [
+    shape=doubleoctagon
+    label="h1",
+    fillcolor="#4f4f4f",
+    style=filled,
+  ];
+  h2 [
+    shape=doubleoctagon
+    label="h2",
+    fillcolor="#4f4f4f",
+    style=filled,
+  ];
+
+  # Switches
+  s1 [
+    shape=oval,
+    label="sw1\n192.168.1.0/24",
+    fillcolor="#d0e0d0",
+    style=filled,
+  ];
+  s2 [
+    shape=oval,
+    label="sw2\n192.168.2.0/24",
+    fillcolor="#d0e0d0",
+    style=filled,
+  ];
+  s3 [
+    shape=oval,
+    label="sw3\n192.168.10.0/24",
+    fillcolor="#d0e0d0",
+    style=filled,
+  ];
+  s4 [
+    shape=oval,
+    label="sw3\n192.168.30.0/24",
+    fillcolor="#d0e0d0",
+    style=filled,
+  ];
+
+  # Connections
+  r1 -- s1 [label="eth0\n.2"];
+  r2 -- s1 [label="eth0\n.1"];
+
+  r2 -- s2 [label="eth1\n.1"];
+  r3 -- s2 [label="eth0\n.2"];
+
+  r1 -- s3 [label="eth1\n.1"];
+  h1 -- s3 [label="eth0\n.2"];
+
+  r3 -- s4 [label="eth1\n.1"];
+  h2 -- s4 [label="eth0\n.2"];
+}
diff --git a/tests/topotests/msdp_mesh_topo1/test_msdp_mesh_topo1.png b/tests/topotests/msdp_mesh_topo1/test_msdp_mesh_topo1.png
new file mode 100644
index 000000000..9a15b8b08
--- /dev/null
+++ b/tests/topotests/msdp_mesh_topo1/test_msdp_mesh_topo1.png
diff --git a/tests/topotests/msdp_mesh_topo1/test_msdp_mesh_topo1.py b/tests/topotests/msdp_mesh_topo1/test_msdp_mesh_topo1.py
new file mode 100644
index 000000000..719ead091
--- /dev/null
+++ b/tests/topotests/msdp_mesh_topo1/test_msdp_mesh_topo1.py
@@ -0,0 +1,296 @@
+#!/usr/bin/env python
+
+#
+# test_msdp_mesh_topo1.py
+# Part of NetDEF Topology Tests
+#
+# Copyright (C) 2021 by
+# Network Device Education Foundation, Inc. ("NetDEF")
+#
+# Permission to use, copy, modify, and/or distribute this software
+# for any purpose with or without fee is hereby granted, provided
+# that the above copyright notice and this permission notice appear
+# in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND NETDEF DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NETDEF BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY
+# DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
+# WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
+# ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+# OF THIS SOFTWARE.
+#
+
+"""
+test_msdp_mesh_topo1.py: Test the FRR PIM MSDP mesh groups.
+"""
+
+import os
+import sys
+import json
+from functools import partial
+import pytest
+import socket
+
+# Save the Current Working Directory to find configuration files.
+CWD = os.path.dirname(os.path.realpath(__file__))
+sys.path.append(os.path.join(CWD, "../"))
+
+# pylint: disable=C0413
+# Import topogen and topotest helpers
+from lib import topotest
+from lib.topogen import Topogen, TopoRouter, get_topogen
+from lib.topolog import logger
+
+# Required to instantiate the topology builder class.
+from mininet.topo import Topo
+
+pytestmark = [pytest.mark.bgpd, pytest.mark.ospfd, pytest.mark.pimd]
+
+#
+# Test global variables:
+# They are used to handle communicating with external application.
+#
+APP_SOCK_PATH = '/tmp/topotests/apps.sock'
+HELPER_APP_PATH = os.path.join(CWD, "../lib/mcast-tester.py")
+app_listener = None
+app_clients = {}
+
+def listen_to_applications():
+    "Start listening socket to connect with applications."
+    # Remove old socket.
+    try:
+        os.unlink(APP_SOCK_PATH)
+    except OSError:
+        pass
+
+    sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM, 0)
+    sock.bind(APP_SOCK_PATH)
+    sock.listen(10)
+    global app_listener
+    app_listener = sock
+
+def accept_host(host):
+    "Accept connection from application running in hosts."
+    global app_listener, app_clients
+    conn = app_listener.accept()
+    app_clients[host] = {
+        'fd': conn[0],
+        'address': conn[1]
+    }
+
+def close_applications():
+    "Signal applications to stop and close all sockets."
+    global app_listener, app_clients
+
+    # Close listening socket.
+    app_listener.close()
+
+    # Remove old socket.
+    try:
+        os.unlink(APP_SOCK_PATH)
+    except OSError:
+        pass
+
+    # Close all host connections.
+    for host in ["h1", "h2"]:
+        if app_clients.get(host) is None:
+            continue
+        app_clients["h1"]["fd"].close()
+
+
+class MSDPMeshTopo1(Topo):
+    "Test topology builder"
+
+    def build(self, *_args, **_opts):
+        "Build function"
+        tgen = get_topogen(self)
+
+        # Create 3 routers
+        for routern in range(1, 4):
+            tgen.add_router("r{}".format(routern))
+
+        switch = tgen.add_switch("s1")
+        switch.add_link(tgen.gears["r1"])
+        switch.add_link(tgen.gears["r2"])
+
+        switch = tgen.add_switch("s2")
+        switch.add_link(tgen.gears["r2"])
+        switch.add_link(tgen.gears["r3"])
+
+        # Create stub networks for multicast traffic.
+        tgen.add_host("h1", "192.168.10.2/24", "192.168.10.1")
+        switch = tgen.add_switch("s3")
+        switch.add_link(tgen.gears["r1"])
+        switch.add_link(tgen.gears["h1"])
+
+        tgen.add_host("h2", "192.168.30.2/24", "192.168.30.1")
+        switch = tgen.add_switch("s4")
+        switch.add_link(tgen.gears["r3"])
+        switch.add_link(tgen.gears["h2"])
+
+
+def setup_module(mod):
+    "Sets up the pytest environment"
+    tgen = Topogen(MSDPMeshTopo1, mod.__name__)
+    tgen.start_topology()
+
+    router_list = tgen.routers()
+    for rname, router in router_list.items():
+        daemon_file = "{}/{}/zebra.conf".format(CWD, rname)
+        if os.path.isfile(daemon_file):
+            router.load_config(TopoRouter.RD_ZEBRA, daemon_file)
+
+        daemon_file = "{}/{}/bgpd.conf".format(CWD, rname)
+        if os.path.isfile(daemon_file):
+            router.load_config(TopoRouter.RD_BGP, daemon_file)
+
+        daemon_file = "{}/{}/ospfd.conf".format(CWD, rname)
+        if os.path.isfile(daemon_file):
+            router.load_config(TopoRouter.RD_OSPF, daemon_file)
+
+        daemon_file = "{}/{}/pimd.conf".format(CWD, rname)
+        if os.path.isfile(daemon_file):
+            router.load_config(TopoRouter.RD_PIM, daemon_file)
+
+    # Initialize all routers.
+    tgen.start_router()
+
+    # Start applications socket.
+    listen_to_applications()
+
+
+def test_wait_ospf_convergence():
+    "Wait for OSPF to converge"
+    tgen = get_topogen()
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    logger.info("waiting for protocols to converge")
+
+    def expect_loopback_route(router, iptype, route, proto):
+        "Wait until route is present on RIB for protocol."
+        logger.info("waiting route {} in {}".format(route, router))
+        test_func = partial(
+            topotest.router_json_cmp,
+            tgen.gears[router],
+            "show {} route json".format(iptype),
+            {route: [{"protocol": proto}]}
+        )
+        _, result = topotest.run_and_expect(test_func, None, count=40, wait=1)
+        assertmsg = '"{}" OSPF convergence failure'.format(router)
+        assert result is None, assertmsg
+
+    # Wait for R1 <-> R2 convergence.
+    expect_loopback_route("r1", "ip", "10.254.254.2/32", "ospf")
+    # Wait for R1 <-> R3 convergence.
+    expect_loopback_route("r1", "ip", "10.254.254.3/32", "ospf")
+
+    # Wait for R2 <-> R1 convergence.
+    expect_loopback_route("r2", "ip", "10.254.254.1/32", "ospf")
+    # Wait for R2 <-> R3 convergence.
+    expect_loopback_route("r2", "ip", "10.254.254.3/32", "ospf")
+
+    # Wait for R3 <-> R1 convergence.
+    expect_loopback_route("r3", "ip", "10.254.254.1/32", "ospf")
+    # Wait for R3 <-> R2 convergence.
+    expect_loopback_route("r3", "ip", "10.254.254.2/32", "ospf")
+
+
+def test_wait_msdp_convergence():
+    "Wait for MSDP to converge"
+    tgen = get_topogen()
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    logger.info("test MSDP convergence")
+
+    tgen.gears["h1"].run("{} --send='0.7' '{}' '{}' '{}' &".format(
+        HELPER_APP_PATH, APP_SOCK_PATH, '229.0.1.10', 'h1-eth0'))
+    accept_host("h1")
+
+    tgen.gears["h2"].run("{} '{}' '{}' '{}' &".format(
+        HELPER_APP_PATH, APP_SOCK_PATH, '229.0.1.10', 'h2-eth0'))
+    accept_host("h2")
+
+    def expect_msdp_peer(router, peer, sa_count=0):
+        "Expect MSDP peer connection to be established with SA amount."
+        logger.info("waiting MSDP connection from peer {} on router {}".format(peer, router))
+        test_func = partial(
+            topotest.router_json_cmp,
+            tgen.gears[router],
+            "show ip msdp peer json",
+            {peer: {"state": "established", "saCount": sa_count}}
+        )
+        _, result = topotest.run_and_expect(test_func, None, count=30, wait=1)
+        assertmsg = '"{}" MSDP connection failure'.format(router)
+        assert result is None, assertmsg
+
+    # R1 peers.
+    expect_msdp_peer("r1", "10.254.254.2")
+    expect_msdp_peer("r1", "10.254.254.3")
+
+    # R2 peers.
+    expect_msdp_peer("r2", "10.254.254.1", 1)
+    expect_msdp_peer("r2", "10.254.254.3")
+
+    # R3 peers.
+    expect_msdp_peer("r3", "10.254.254.1", 1)
+    expect_msdp_peer("r3", "10.254.254.2")
+
+
+def test_msdp_sa_configuration():
+    "Expect the multicast traffic SA to be created"
+    tgen = get_topogen()
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    logger.info("test MSDP SA")
+
+    def expect_msdp_sa(router, source, group, local, rp, spt_setup):
+        "Expect MSDP SA."
+        logger.info("waiting MSDP SA on router {}".format(router))
+        test_func = partial(
+            topotest.router_json_cmp,
+            tgen.gears[router],
+            "show ip msdp sa json",
+            {group: {source: {"local": local, "rp": rp, "sptSetup": spt_setup}}}
+        )
+        _, result = topotest.run_and_expect(test_func, None, count=30, wait=1)
+        assertmsg = '"{}" MSDP SA failure'.format(router)
+        assert result is None, assertmsg
+
+    source = "192.168.10.2"
+    group = "229.0.1.10"
+    rp = "10.254.254.1"
+
+    # R1 SA.
+    expect_msdp_sa("r1", source, group, "yes", "-", "-")
+
+    # R2 SA.
+    expect_msdp_sa("r2", source, group, "no", rp, "no")
+
+    # R3 peers.
+    expect_msdp_sa("r3", source, group, "no", rp, "yes")
+
+
+def teardown_module(_mod):
+    "Teardown the pytest environment"
+    tgen = get_topogen()
+    close_applications()
+    tgen.stop_topology()
+
+
+def test_memory_leak():
+    "Run the memory leak test and report results."
+    tgen = get_topogen()
+    if not tgen.is_memleak_enabled():
+        pytest.skip("Memory leak test/report is disabled")
+
+    tgen.report_memory_leaks()
+
+
+if __name__ == "__main__":
+    args = ["-s"] + sys.argv[1:]
+    sys.exit(pytest.main(args))
diff --git a/yang/frr-pim.yang b/yang/frr-pim.yang
index 70adb37b2..4c4819ac2 100644
--- a/yang/frr-pim.yang
+++ b/yang/frr-pim.yang
@@ -174,26 +174,36 @@ module frr-pim {
         "Enable ssmpingd operation.";
     }
 
-    container msdp-mesh-group {
-      presence
-        "Configure MSDP mesh-group.";
+    list msdp-mesh-groups {
+      key "name";
+      description
+        "RFC 3618 Section 10.2. MSDP mesh-group semantics
 
-      leaf mesh-group-name {
-        type string;
+         Groups multiple MSDP peers to reduce SA flooding typically used
+         in intra-domain settings.";
+
+      leaf name {
+        type string {
+          length 1..64;
+        }
         description
-          "MSDP mesh group name.";
+          "The mesh group name.";
       }
 
-      leaf-list member-ip {
+      leaf source {
         type inet:ip-address;
         description
-          "Peer ip address.";
+          "Source IP address for the TCP connections.";
       }
 
-      leaf source-ip {
-        type inet:ip-address;
-        description
-          "Source ip address for the TCP connection.";
+      list members {
+        key "address";
+
+        leaf address {
+          type inet:ip-address;
+          description
+            "Peer member IP address.";
+        }
       }
     }