diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index 0346eaa6d236429ac736eb19c763dfb780bc4fdb..19d3664ab9dd87c19077e47311e2872f016c725e 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -339,6 +339,11 @@ static int vxlan_fdb_info(struct sk_buff *skb, struct vxlan_dev *vxlan,
 	ndm->ndm_flags = fdb->flags;
 	ndm->ndm_type = RTN_UNICAST;
 
+	if (!net_eq(dev_net(vxlan->dev), vxlan->net) &&
+	    nla_put_s32(skb, NDA_NDM_IFINDEX_NETNSID,
+			peernet2id(vxlan->net, dev_net(vxlan->dev))))
+		goto nla_put_failure;
+
 	if (send_eth && nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->eth_addr))
 		goto nla_put_failure;
 
diff --git a/include/uapi/linux/neighbour.h b/include/uapi/linux/neighbour.h
index f3d77f9f1e0bb582b1f1ca02fd8bd99ff60729dd..38f236853cc0742a3c2e71c0c6137c1d308c2dd4 100644
--- a/include/uapi/linux/neighbour.h
+++ b/include/uapi/linux/neighbour.h
@@ -25,6 +25,7 @@ enum {
 	NDA_VNI,
 	NDA_IFINDEX,
 	NDA_MASTER,
+	NDA_NDM_IFINDEX_NETNSID,
 	__NDA_MAX
 };
 
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 9d1a4cac83b604cf657f1492628dbc4966db8eca..b7bde551ef76901de0456d811112ba232aa350ba 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -202,6 +202,7 @@ int peernet2id(struct net *net, struct net *peer)
 
 	return id >= 0 ? id : NETNSA_NSID_NOT_ASSIGNED;
 }
+EXPORT_SYMBOL(peernet2id);
 
 struct net *get_net_ns_by_id(struct net *net, int id)
 {