From a27fdb99111c6d20354d032db26cc0117b34e58a Mon Sep 17 00:00:00 2001
From: Pim van Pelt <pim@ipng.nl>
Date: Tue, 8 Mar 2022 13:42:56 +0000
Subject: [PATCH] Backport https://gerrit.fd.io/r/c/vpp/+/35523

---
 lcpng_nl_sync.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/lcpng_nl_sync.c b/lcpng_nl_sync.c
index ab5ad64..e1b917c 100644
--- a/lcpng_nl_sync.c
+++ b/lcpng_nl_sync.c
@@ -967,6 +967,12 @@ lcp_nl_neigh_add (struct rtnl_neigh *rn)
       return;
     }
 
+  if (ip46_address_is_multicast (&ip_addr_46 (&nh)))
+    {
+      NL_DBG ("neigh_add: ignore multicast %U", format_nl_object, rn);
+      return;
+    }
+
   lcp_nl_mk_ip_addr (rtnl_neigh_get_dst (rn), &nh);
   ll = rtnl_neigh_get_lladdr (rn);
   state = rtnl_neigh_get_state (rn);
@@ -1017,6 +1023,12 @@ lcp_nl_neigh_del (struct rtnl_neigh *rn)
       return;
     }
 
+  if (ip46_address_is_multicast (&ip_addr_46 (&nh)))
+    {
+      NL_DBG ("neigh_del: ignore multicast %U", format_nl_object, rn);
+      return;
+    }
+
   lcp_nl_mk_ip_addr (rtnl_neigh_get_dst (rn), &nh);
   rv = ip_neighbor_del (&nh, lip->lip_phy_sw_if_index);