Merge pull request #15228 from FRRouting/mergify/bp/stable/9.1/pr-15206

pbrd: Fix PBR handling for last rule deletion (backport #15206)

pbrd/pbr_nht.c

@@ -649,7 +649,15 @@ static void pbr_nht_release_individual_nexthop(struct pbr_map_sequence *pbrms)
 
 void pbr_nht_delete_individual_nexthop(struct pbr_map_sequence *pbrms)
 {
-	pbr_map_delete_nexthops(pbrms);
+	struct pbr_map *pbrm = pbrms->parent;
+
+	/* The idea here is to send a delete command to zebra only once,
+	 * and set 'valid' and 'installed' to false only when the last
+	 * rule is being deleted. In other words, the pbr common should be
+	 * updated only when the last rule is being updated or deleted.
+	 */
+	if (pbrm->seqnumbers->count == 1)
+		pbr_map_delete_nexthops(pbrms);
 
 	pbr_nht_release_individual_nexthop(pbrms);
 }