Index: in6.c
===================================================================
--- in6.c	(revision 260904)
+++ in6.c	(working copy)
@@ -1530,6 +1530,9 @@ in6_purgeaddr(struct ifaddr *ifa)
 	/* Remove local address entry from lltable. */
 	nd6_rem_ifa_lle(ia);
 
+	/* stop NS deferred processing */
+	nd6_ns_drain(ifp);
+
 	/* Leave multicast groups. */
 	error = in6_purgeaddr_mc(ifp, ia, ifa0);
 
Index: nd6_nbr.c
===================================================================
--- nd6_nbr.c	(revision 260904)
+++ nd6_nbr.c	(working copy)
@@ -51,6 +51,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/syslog.h>
 #include <sys/queue.h>
 #include <sys/callout.h>
+#include <sys/taskqueue.h>
 
 #include <net/if.h>
 #include <net/if_types.h>
@@ -93,6 +94,21 @@ VNET_DEFINE(int, dad_maxtry) = 15;	/* max # of *tr
 #define	V_dad_ignore_ns			VNET(dad_ignore_ns)
 #define	V_dad_maxtry			VNET(dad_maxtry)
 
+struct nd6_ns {
+	STAILQ_ENTRY(nd6_ns)	entry;
+	struct ifnet		*ifp;
+	struct in6_addr		src;
+	struct in6_addr		dst;
+	struct in6_addr		tgt;
+};
+
+static STAILQ_HEAD(, nd6_ns)	nd6_tasks;
+static struct task		nd6_ns_task;
+static struct mtx		nd6_ns_lock;
+#define	ND6_NS_LOCK_INIT()	mtx_init(&nd6_ns_lock, \
+    "nd6_ns_lock", NULL, MTX_DEF)
+#define	ND6_NS_LOCK()		mtx_lock(&nd6_ns_lock)
+#define	ND6_NS_UNLOCK()		mtx_unlock(&nd6_ns_lock)
 /*
  * Input a Neighbor Solicitation Message.
  *
@@ -378,7 +394,67 @@ nd6_ns_input(struct mbuf *m, int off, int icmp6len
  *   ln - for source address determination
  *  dad - duplicate address detection
  */
+
 void
+nd6_ns_init(void)
+{
+
+#ifdef VIMAGE
+	if (!IS_DEFAULT_VNET(curvnet))
+		return;
+#endif
+	STAILQ_INIT(&nd6_tasks);
+	TASK_INIT(&nd6_ns_task, 0, nd6_process_ns_tasks, NULL);
+	ND6_NS_LOCK_INIT();
+}
+
+static void
+nd6_process_ns_tasks(void *arg __unused, int pending)
+{
+	struct nd6_ns *ns;
+	STAILQ_HEAD(, nd6_ns) tasks;
+
+	STAILQ_INIT(&tasks);
+	for (;;) {
+		ND6_NS_LOCK();
+		if (STAILQ_FIRST(&nd6_tasks) == NULL) {
+			ND6_NS_UNLOCK();
+			break;
+		}
+		STAILQ_SWAP(&nd6_tasks, &tasks, entry);
+		ND6_NS_UNLOCK();
+		while ((ns = STAILQ_FIRST(&tasks)) != NULL) {
+			STAILQ_REMOVE_HEAD(&tasks, entry);
+			nd6_ns_output(ns->ifp, &ns->src, &ns->dst, &ns->tgt);
+			free(ns, M_TMP);
+		}
+	}
+}
+
+int
+nd6_ns_output_sched(struct ifnet *ifp, const struct in6_addr *src,
+    const struct in6_addr *dst, const struct in6_addr *tgt)
+{
+	struct nd6_ns *ns;
+
+	ns = malloc(sizeof(*ns), M_TEMP, M_NOWAIT | M_ZERO);
+	if (ns == NULL)
+		return (ENOMEM);
+	ns->ifp = ifp;
+	if (src != NULL)
+		ns->src = *src;
+	if (dst != NULL)
+		ns->dst = *dst;
+	if (tgt != NULL)
+		ns->tgt = *tgt;
+	ND6_NS_LOCK();
+	SLIST_INSERT_TAIL(&nd6_tasks, ns, entry);
+	ND6_NS_UNLOCK();
+	taskqueue_enqueue(taskqueue_thread, &nd6_ns_task);
+	return (0);
+}
+
+void
 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *daddr6, 
     const struct in6_addr *taddr6, struct llentry *ln, int dad)
 {