diff --git a/sys/kern/kern_mbuf.c b/sys/kern/kern_mbuf.c
--- a/sys/kern/kern_mbuf.c
+++ b/sys/kern/kern_mbuf.c
@@ -1635,6 +1635,28 @@
 	counter_u64_add(snd_tag_count, -1);
 }
 
+void
+m_rcvif_serialize(struct mbuf *m)
+{
+	u_short idx, gen;
+
+	M_ASSERTPKTHDR(m);
+	idx = m->m_pkthdr.rcvif->if_index;
+	gen = m->m_pkthdr.rcvif->if_idxgen;
+	m->m_pkthdr.rcvidx = idx;
+	m->m_pkthdr.rcvgen = gen;
+}
+
+struct ifnet *
+m_rcvif_restore(struct mbuf *m)
+{
+
+	M_ASSERTPKTHDR(m);
+
+	return ((m->m_pkthdr.rcvif = ifnet_byindexgen(m->m_pkthdr.rcvidx,
+	    m->m_pkthdr.rcvgen)));
+}
+
 /*
  * Allocate an mbuf with anonymous external pages.
  */
diff --git a/sys/net/if.c b/sys/net/if.c
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -313,7 +313,10 @@
 /* Table of ifnet by index. */
 static int if_index;
 static int if_indexlim = 8;
-static struct ifnet **ifindex_table;
+static struct ifindex_entry {
+	struct ifnet	*ife_ifnet;
+	uint16_t	ife_gencnt;
+} *ifindex_table;
 
 SYSCTL_NODE(_net_link_generic, IFMIB_SYSTEM, system,
     CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
@@ -325,8 +328,8 @@
 
 	IFNET_RLOCK();
 	for (int i = 1; i <= if_index; i++)
-		if (ifindex_table[i] != NULL &&
-		    ifindex_table[i]->if_vnet == curvnet)
+		if (ifindex_table[i].ife_ifnet != NULL &&
+		    ifindex_table[i].ife_ifnet->if_vnet == curvnet)
 			rv = i;
 	IFNET_RUNLOCK();
 
@@ -370,7 +373,7 @@
 	if (__predict_false(idx > if_index))
 		return (NULL);
 
-	ifp = ck_pr_load_ptr(&ifindex_table[idx]);
+	ifp = ck_pr_load_ptr(&ifindex_table[idx].ife_ifnet);
 
 	if (curvnet != NULL && ifp != NULL && ifp->if_vnet != curvnet)
 		ifp = NULL;
@@ -391,6 +394,24 @@
 	return (ifp);
 }
 
+struct ifnet *
+ifnet_byindexgen(uint16_t idx, uint16_t gen)
+{
+	struct ifnet *ifp;
+
+	NET_EPOCH_ASSERT();
+
+	if (__predict_false(idx > if_index))
+		return (NULL);
+
+	ifp = ck_pr_load_ptr(&ifindex_table[idx].ife_ifnet);
+
+	if (ifindex_table[idx].ife_gencnt == gen)
+		return (ifp);
+	else
+		return (NULL);
+}
+
 struct ifaddr *
 ifaddr_byindex(u_short idx)
 {
@@ -571,13 +592,13 @@
 	 * next slot.
 	 */
 	for (idx = 1; idx <= if_index; idx++) {
-		if (ifindex_table[idx] == NULL)
+		if (ifindex_table[idx].ife_ifnet == NULL)
 			break;
 	}
 
 	/* Catch if_index overflow. */
 	if (idx >= if_indexlim) {
-		struct ifnet **new, **old;
+		struct ifindex_entry *new, *old;
 		int newlim;
 
 		newlim = if_indexlim * 2;
@@ -593,7 +614,8 @@
 		if_index = idx;
 
 	ifp->if_index = idx;
-	ck_pr_store_ptr(&ifindex_table[idx], ifp);
+	ifp->if_idxgen = ifindex_table[idx].ife_gencnt;
+	ck_pr_store_ptr(&ifindex_table[idx].ife_ifnet, ifp);
 	IFNET_WUNLOCK();
 
 	return (ifp);
@@ -668,9 +690,10 @@
 	 * virtualized and interface would outlive the vnet.
 	 */
 	IFNET_WLOCK();
-	MPASS(ifindex_table[ifp->if_index] == ifp);
-	ck_pr_store_ptr(&ifindex_table[ifp->if_index], NULL);
-	while (if_index > 0 && ifindex_table[if_index] == NULL)
+	MPASS(ifindex_table[ifp->if_index].ife_ifnet == ifp);
+	ck_pr_store_ptr(&ifindex_table[ifp->if_index].ife_ifnet, NULL);
+	ifindex_table[ifp->if_index].ife_gencnt++;
+	while (if_index > 0 && ifindex_table[if_index].ife_ifnet == NULL)
 		if_index--;
 	IFNET_WUNLOCK();
 
@@ -819,7 +842,7 @@
 	struct sockaddr_dl *sdl;
 	struct ifaddr *ifa;
 
-	MPASS(ifindex_table[ifp->if_index] == ifp);
+	MPASS(ifindex_table[ifp->if_index].ife_ifnet == ifp);
 
 #ifdef VIMAGE
 	ifp->if_vnet = curvnet;
@@ -4508,8 +4531,8 @@
 	IF_DB_PRINTF("%d", if_dunit);
 	IF_DB_PRINTF("%s", if_description);
 	IF_DB_PRINTF("%u", if_index);
+	IF_DB_PRINTF("%d", if_idxgen);
 	IF_DB_PRINTF("%u", if_refcount);
-	IF_DB_PRINTF("%d", if_index_reserved);
 	IF_DB_PRINTF("%p", if_softc);
 	IF_DB_PRINTF("%p", if_l2com);
 	IF_DB_PRINTF("%p", if_llsoftc);
@@ -4564,7 +4587,7 @@
 	u_short idx;
 
 	for (idx = 1; idx <= if_index; idx++) {
-		ifp = ifindex_table[idx];
+		ifp = ifindex_table[idx].ife_ifnet;
 		if (ifp == NULL)
 			continue;
 		db_printf( "%20s ifp=%p\n", ifp->if_xname, ifp);
diff --git a/sys/net/if_var.h b/sys/net/if_var.h
--- a/sys/net/if_var.h
+++ b/sys/net/if_var.h
@@ -334,7 +334,7 @@
 	const char *if_dname;		/* driver name */
 	int	if_dunit;		/* unit or IF_DUNIT_NONE */
 	u_short	if_index;		/* numeric abbreviation for this if  */
-	short	if_index_reserved;	/* spare space to grow if_index */
+	u_short	if_idxgen;		/* ... and its generation count */
 	char	if_xname[IFNAMSIZ];	/* external name (name + unit) */
 	char	*if_description;	/* interface description */
 
@@ -644,6 +644,13 @@
 struct ifnet	*ifnet_byindex(u_int);
 struct ifnet	*ifnet_byindex_ref(u_int);
 
+/*
+ * ifnet_byindexgen() looks up ifnet by index and generation count,
+ * attempting to restore a weak pointer that had been stored across
+ * the epoch.
+ */
+struct ifnet   *ifnet_byindexgen(uint16_t idx, uint16_t gen);
+
 /*
  * Given the index, ifaddr_byindex() returns the one and only
  * link-level ifaddr for the interface. You are not supposed to use
diff --git a/sys/sys/mbuf.h b/sys/sys/mbuf.h
--- a/sys/sys/mbuf.h
+++ b/sys/sys/mbuf.h
@@ -159,6 +159,10 @@
 	union {
 		struct m_snd_tag *snd_tag;	/* send tag, if any */
 		struct ifnet	*rcvif;		/* rcv interface */
+		struct {
+			uint16_t rcvidx;	/* rcv interface index ... */
+			uint16_t rcvgen;	/* ... and generation count */
+		};
 	};
 	SLIST_HEAD(packet_tags, m_tag) tags; /* list of packet tags */
 	int32_t		 len;		/* total packet length */
@@ -862,6 +866,8 @@
 void		 m_snd_tag_init(struct m_snd_tag *, struct ifnet *,
 		    const struct if_snd_tag_sw *);
 void		 m_snd_tag_destroy(struct m_snd_tag *);
+void		 m_rcvif_serialize(struct mbuf *);
+struct ifnet	*m_rcvif_restore(struct mbuf *);
 
 static __inline int
 m_gettype(int size)