diff --git a/bgpd/bgp_nb_config.c b/bgpd/bgp_nb_config.c
index ff2c8ce93e..8ca7836a99 100644
--- a/bgpd/bgp_nb_config.c
+++ b/bgpd/bgp_nb_config.c
@@ -111,15 +111,24 @@ int bgp_router_create(struct nb_cb_create_args *args)
 			is_new_bgp = (bgp_lookup_by_name(name) == NULL);
 
 		ret = bgp_get_vty(&bgp, &as, name, inst_type);
-		switch (ret) {
-		case BGP_ERR_AS_MISMATCH:
-			snprintf(args->errmsg, args->errmsg_len,
-				 "BGP instance is already running; AS is %u",
-				 as);
-			return NB_ERR_INCONSISTENCY;
-		case BGP_ERR_INSTANCE_MISMATCH:
-			snprintf(args->errmsg, args->errmsg_len,
-				 "BGP instance type mismatch");
+		if (ret) {
+			switch (ret) {
+			case BGP_ERR_AS_MISMATCH:
+				snprintf(
+					args->errmsg, args->errmsg_len,
+					"BGP instance is already running; AS is %u",
+					as);
+				break;
+			case BGP_ERR_INSTANCE_MISMATCH:
+				snprintf(args->errmsg, args->errmsg_len,
+					 "BGP instance type mismatch");
+				break;
+			}
+
+			UNSET_FLAG(bgp->vrf_flags, BGP_VRF_AUTO);
+
+			nb_running_set_entry(args->dnode, bgp);
+
 			return NB_ERR_INCONSISTENCY;
 		}
 
@@ -221,64 +230,26 @@ int bgp_router_destroy(struct nb_cb_destroy_args *args)
 int bgp_global_local_as_modify(struct nb_cb_modify_args *args)
 {
 	struct bgp *bgp;
-	as_t as;
-	const struct lyd_node *vrf_dnode;
-	const char *vrf_name;
-	const char *name = NULL;
-	enum bgp_instance_type inst_type;
-	int ret;
-	bool is_view_inst = false;
 
 	switch (args->event) {
 	case NB_EV_VALIDATE:
-		as = yang_dnode_get_uint32(args->dnode, NULL);
-
-		inst_type = BGP_INSTANCE_TYPE_DEFAULT;
-
-		vrf_dnode = yang_dnode_get_parent(args->dnode,
-						  "control-plane-protocol");
-		vrf_name = yang_dnode_get_string(vrf_dnode, "./vrf");
-
-		if (strmatch(vrf_name, VRF_DEFAULT_NAME)) {
-			name = NULL;
-		} else {
-			name = vrf_name;
-			inst_type = BGP_INSTANCE_TYPE_VRF;
-		}
-
-		is_view_inst = yang_dnode_get_bool(args->dnode,
-						   "../instance-type-view");
-		if (is_view_inst)
-			inst_type = BGP_INSTANCE_TYPE_VIEW;
-
-		ret = bgp_lookup_by_as_name_type(&bgp, &as, name, inst_type);
-		switch (ret) {
-		case BGP_ERR_AS_MISMATCH:
+		/*
+		 * Changing AS number is not allowed, but we must allow it
+		 * once, when the BGP instance is created the first time.
+		 * If the instance already exists - return the validation
+		 * error.
+		 */
+		bgp = nb_running_get_entry_non_rec(args->dnode->parent->parent,
+						   NULL, false);
+		if (bgp) {
 			snprintf(args->errmsg, args->errmsg_len,
-				 "BGP instance is already running; AS is %u",
-				 as);
-			return NB_ERR_VALIDATION;
-		case BGP_ERR_INSTANCE_MISMATCH:
-			snprintf(args->errmsg, args->errmsg_len,
-				 "BGP instance type mismatch");
+				 "Changing AS number is not allowed");
 			return NB_ERR_VALIDATION;
 		}
 		break;
 	case NB_EV_PREPARE:
 	case NB_EV_ABORT:
-		return NB_OK;
 	case NB_EV_APPLY:
-		/* NOTE: handled in bgp_global_create callback, the as change
-		 * will be rejected in validate phase.
-		 */
-		as = yang_dnode_get_uint32(args->dnode, NULL);
-		bgp = nb_running_get_entry(args->dnode, NULL, true);
-		if (bgp->as != as) {
-			snprintf(args->errmsg, args->errmsg_len,
-				 "BGP instance is already running; AS is %u",
-				 bgp->as);
-			return NB_ERR_INCONSISTENCY;
-		}
 		break;
 	}
 
@@ -1514,12 +1485,27 @@ int bgp_global_global_config_timers_keepalive_modify(
  */
 int bgp_global_instance_type_view_modify(struct nb_cb_modify_args *args)
 {
+	struct bgp *bgp;
+
 	switch (args->event) {
 	case NB_EV_VALIDATE:
+		/*
+		 * Changing instance type is not allowed, but we must allow it
+		 * once, when the BGP instance is created the first time.
+		 * If the instance already exists - return the validation
+		 * error.
+		 */
+		bgp = nb_running_get_entry_non_rec(args->dnode->parent->parent,
+						   NULL, false);
+		if (bgp) {
+			snprintf(args->errmsg, args->errmsg_len,
+				 "Changing instance type is not allowed");
+			return NB_ERR_VALIDATION;
+		}
+		break;
 	case NB_EV_PREPARE:
 	case NB_EV_ABORT:
 	case NB_EV_APPLY:
-		/* TODO: implement me. */
 		break;
 	}
 
diff --git a/bgpd/bgp_vty.c b/bgpd/bgp_vty.c
index 36aa3e1a3e..5b5f166e4b 100644
--- a/bgpd/bgp_vty.c
+++ b/bgpd/bgp_vty.c
@@ -1380,6 +1380,10 @@ DEFUN_YANG_NOSH(router_bgp,
 			nb_cli_enqueue_change(vty,
 					      "./global/instance-type-view",
 					      NB_OP_MODIFY, "true");
+		} else {
+			nb_cli_enqueue_change(vty,
+					      "./global/instance-type-view",
+					      NB_OP_MODIFY, "false");
 		}
 
 		ret = nb_cli_apply_changes(vty, base_xpath);
diff --git a/bgpd/bgpd.c b/bgpd/bgpd.c
index 5e731eb5a0..9d2ff9c00e 100644
--- a/bgpd/bgpd.c
+++ b/bgpd/bgpd.c
@@ -3378,13 +3378,13 @@ int bgp_lookup_by_as_name_type(struct bgp **bgp_val, as_t *as, const char *name,
 		bgp = bgp_get_default();
 
 	if (bgp) {
+		*bgp_val = bgp;
 		if (bgp->as != *as) {
 			*as = bgp->as;
 			return BGP_ERR_AS_MISMATCH;
 		}
 		if (bgp->inst_type != inst_type)
 			return BGP_ERR_INSTANCE_MISMATCH;
-		*bgp_val = bgp;
 		return BGP_SUCCESS;
 	}
 	*bgp_val = NULL;