Index: contrib/ipfilter/tools/ipftest.c
===================================================================
--- contrib/ipfilter/tools/ipftest.c
+++ contrib/ipfilter/tools/ipftest.c
@@ -865,10 +865,18 @@
 	}
 }
 
+unsigned
+ip_initid(void)
+{
+	return (0);
+}
+
 void
-ip_fillid(struct ip *ip)
+ip_fillid(struct ip *ip, unsigned *pid)
 {
 	static uint16_t ip_id;
-
-	ip->ip_id = ip_id++;
+	if (pid != NULL)
+		ip->ip_id = (*pid)++
+	else
+		ip->ip_id = ip_id++;
 }
Index: sys/contrib/ipfilter/netinet/fil.c
===================================================================
--- sys/contrib/ipfilter/netinet/fil.c
+++ sys/contrib/ipfilter/netinet/fil.c
@@ -6096,7 +6096,7 @@
 		id = (u_short)sum;
 		ip->ip_id = htons(id);
 	} else {
-		ip_fillid(ip);
+		ip_fillid(ip, NULL);
 		id = ntohs(ip->ip_id);
 		if ((fin->fin_flx & FI_FRAG) != 0)
 			(void) ipf_frag_ipidnew(fin, (u_32_t)id);
Index: sys/contrib/ipfilter/netinet/ip_fil.h
===================================================================
--- sys/contrib/ipfilter/netinet/ip_fil.h
+++ sys/contrib/ipfilter/netinet/ip_fil.h
@@ -1718,7 +1718,8 @@
 extern	void	m_freem __P((mb_t *));
 extern	size_t	msgdsize __P((mb_t *));
 extern	int	bcopywrap __P((void *, void *, size_t));
-extern	void	ip_fillid(struct ip *);
+extern	unsigned	ip_initid(void);
+extern	void	ip_fillid(struct ip *, unsigned *);
 #else /* #ifndef _KERNEL */
 # if defined(__NetBSD__) && defined(PFIL_HOOKS)
 extern	void	ipfilterattach __P((int));
Index: sys/contrib/ipfilter/netinet/ip_nat.h
===================================================================
--- sys/contrib/ipfilter/netinet/ip_nat.h
+++ sys/contrib/ipfilter/netinet/ip_nat.h
@@ -661,6 +661,7 @@
 	ipftq_t		ipf_nat_pending;
 	ipftq_t		ipf_nat_tcptq[IPF_TCP_NSTATES];
 	natstat_t	ipf_nat_stats;
+	unsigned	ipf_nat_ip_id;	/* IP ID number */
 } ipf_nat_softc_t ;
 
 #define	ipf_nat_map_max			ipf_nat_map_mask.imt4_max
Index: sys/contrib/ipfilter/netinet/ip_nat.c
===================================================================
--- sys/contrib/ipfilter/netinet/ip_nat.c
+++ sys/contrib/ipfilter/netinet/ip_nat.c
@@ -319,6 +319,7 @@
 
 	bzero((char *)softn, sizeof(*softn));
 
+	softn->ipf_nat_ip_id = ip_initid();
 	softn->ipf_nat_tune = ipf_tune_array_copy(softn,
 						  sizeof(ipf_nat_tuneables),
 						  ipf_nat_tuneables);
@@ -5221,7 +5222,7 @@
 		}
 
 		ip = MTOD(m, ip_t *);
-		ip_fillid(ip);
+		ip_fillid(ip, &softn->ipf_nat_ip_id);
 		s2 = ntohs(ip->ip_id);
 
 		s1 = ip->ip_len;
Index: sys/net/if_gre.h
===================================================================
--- sys/net/if_gre.h
+++ sys/net/if_gre.h
@@ -82,6 +82,7 @@
 #endif
 	} gre_uhdr;
 	const struct encaptab	*gre_ecookie;
+	unsigned		gre_ip_id;	/* IP ID number */
 };
 #define	GRE2IFP(sc)		((sc)->gre_ifp)
 #define	GRE_LOCK_INIT(sc)	rm_init(&(sc)->gre_lock, "gre softc")
@@ -103,7 +104,7 @@
 int	gre_input(struct mbuf **, int *, int);
 #ifdef INET
 int	in_gre_attach(struct gre_softc *);
-int	in_gre_output(struct mbuf *, int, int);
+int	in_gre_output(struct gre_softc *, struct mbuf *, int, int);
 #endif
 #ifdef INET6
 int	in6_gre_attach(struct gre_softc *);
Index: sys/net/if_gre.c
===================================================================
--- sys/net/if_gre.c
+++ sys/net/if_gre.c
@@ -909,7 +909,7 @@
 	switch (oaf) {
 #ifdef INET
 	case AF_INET:
-		error = in_gre_output(m, iaf, hlen);
+		error = in_gre_output(sc, m, iaf, hlen);
 		break;
 #endif
 #ifdef INET6
Index: sys/netinet/in_pcb.h
===================================================================
--- sys/netinet/in_pcb.h
+++ sys/netinet/in_pcb.h
@@ -220,6 +220,7 @@
 	struct llentry	*inp_lle;	/* cached L2 information */
 	struct rtentry	*inp_rt;	/* cached L3 information */
 	struct rwlock	inp_lock;
+	unsigned	inp_ip_id;	/* (i) IP ID number */
 };
 #define	inp_fport	inp_inc.inc_fport
 #define	inp_lport	inp_inc.inc_lport
Index: sys/netinet/in_pcb.c
===================================================================
--- sys/netinet/in_pcb.c
+++ sys/netinet/in_pcb.c
@@ -280,6 +280,7 @@
 	if (inp == NULL)
 		return (ENOBUFS);
 	bzero(inp, inp_zero_size);
+	inp->inp_ip_id = ip_initid();
 	inp->inp_pcbinfo = pcbinfo;
 	inp->inp_socket = so;
 	inp->inp_cred = crhold(so->so_cred);
Index: sys/netinet/ip_carp.c
===================================================================
--- sys/netinet/ip_carp.c
+++ sys/netinet/ip_carp.c
@@ -118,6 +118,8 @@
 	int			sc_init_counter;
 	uint64_t		sc_counter;
 
+  	unsigned		sc_ip_id;	/* IP ID number */
+
 	/* authentication */
 #define	CARP_HMAC_PAD	64
 	unsigned char sc_key[CARP_KEY_LEN];
@@ -842,7 +844,7 @@
 		ip->ip_ttl = CARP_DFLTTL;
 		ip->ip_p = IPPROTO_CARP;
 		ip->ip_sum = 0;
-		ip_fillid(ip);
+		ip_fillid(ip, &sc->sc_ip_id);
 
 		bzero(&sa, sizeof(sa));
 		sa.sa_family = AF_INET;
@@ -1477,6 +1479,7 @@
 
 	sc = malloc(sizeof(*sc), M_CARP, M_WAITOK|M_ZERO);
 
+	sc->sc_ip_id = ip_initid();
 	sc->sc_advbase = CARP_DFLTINTV;
 	sc->sc_vhid = -1;	/* required setting */
 	sc->sc_init_counter = 1;
Index: sys/netinet/ip_gre.c
===================================================================
--- sys/netinet/ip_gre.c
+++ sys/netinet/ip_gre.c
@@ -125,7 +125,7 @@
 }
 
 int
-in_gre_output(struct mbuf *m, int af, int hlen)
+in_gre_output(struct gre_softc *sc, struct mbuf *m, int af, int hlen)
 {
 	struct greip *gi;
 
@@ -145,7 +145,7 @@
 #ifdef INET6
 	case AF_INET6:
 		gi->gi_ip.ip_tos = 0; /* XXX */
-		ip_fillid(&gi->gi_ip);
+		ip_fillid(&gi->gi_ip, &sc->gre_ip_id);
 		break;
 #endif
 	}
Index: sys/netinet/ip_id.c
===================================================================
--- sys/netinet/ip_id.c
+++ sys/netinet/ip_id.c
@@ -124,7 +124,7 @@
 /*
  * Non-random ID state engine is simply a per-cpu counter.
  */
-static VNET_DEFINE(counter_u64_t, ip_id);
+static VNET_DEFINE(unsigned, ip_id);
 #define	V_ip_id		VNET(ip_id)
 
 static int	sysctl_ip_randomid(SYSCTL_HANDLER_ARGS);
@@ -238,8 +238,16 @@
 	return (new_id);
 }
 
+unsigned
+ip_initid(void)
+{
+	unsigned temp = 0;
+	arc4rand(&temp, sizeof(temp), 0);
+	return (temp);
+}
+
 void
-ip_fillid(struct ip *ip)
+ip_fillid(struct ip *ip, unsigned *pid)
 {
 
 	/*
@@ -252,23 +260,12 @@
 		ip->ip_id = 0;
 	else if (V_ip_do_randomid)
 		ip->ip_id = ip_randomid();
-	else {
-		counter_u64_add(V_ip_id, 1);
-		/*
-		 * There are two issues about this trick, to be kept in mind.
-		 * 1) We can migrate between counter_u64_add() and next
-		 *    line, and grab counter from other CPU, resulting in too
-		 *    quick ID reuse. This is tolerable in our particular case,
-		 *    since probability of such event is much lower then reuse
-		 *    of ID due to legitimate overflow, that at modern Internet
-		 *    speeds happens all the time.
-		 * 2) We are relying on the fact that counter(9) is based on
-		 *    UMA_ZONE_PCPU uma(9) zone. We also take only last
-		 *    sixteen bits of a counter, so we don't care about the
-		 *    fact that machines with 32-bit word update their counters
-		 *    not atomically.
-		 */
-		ip->ip_id = htons((*(uint64_t *)zpcpu_get(V_ip_id)) & 0xffff);
+	else if (pid != NULL) {
+		/* no need to byteswap IP ID field */
+		ip->ip_id = atomic_fetchadd_int(pid, 1) & 0xFFFF;
+	} else {	/* fallback to global IP ID counter */
+		/* no need to byteswap IP ID field */
+		ip->ip_id = atomic_fetchadd_int(&V_ip_id, 1) & 0xFFFF;
 	}
 }
 
@@ -277,9 +274,7 @@
 {
 
 	mtx_init(&V_ip_id_mtx, "ip_id_mtx", NULL, MTX_DEF);
-	V_ip_id = counter_u64_alloc(M_WAITOK);
-	for (int i = 0; i < mp_ncpus; i++)
-		arc4rand(zpcpu_get_cpu(V_ip_id, i), sizeof(uint64_t), 0);
+	V_ip_id = ip_initid();
 }
 VNET_SYSINIT(ip_id, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, ipid_sysinit, NULL);
 
@@ -292,6 +287,5 @@
 		free(V_id_array, M_IPID);
 		free(V_id_bits, M_IPID);
 	}
-	counter_u64_free(V_ip_id);
 }
 VNET_SYSUNINIT(ip_id, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, ipid_sysuninit, NULL);
Index: sys/netinet/ip_mroute.h
===================================================================
--- sys/netinet/ip_mroute.h
+++ sys/netinet/ip_mroute.h
@@ -263,6 +263,7 @@
     u_long		v_pkt_out;	/* # pkts out on interface           */
     u_long		v_bytes_in;	/* # bytes in on interface	     */
     u_long		v_bytes_out;	/* # bytes out on interface	     */
+    unsigned		v_ip_id;	/* IP ID number			     */
 };
 
 #ifdef _KERNEL
Index: sys/netinet/ip_mroute.c
===================================================================
--- sys/netinet/ip_mroute.c
+++ sys/netinet/ip_mroute.c
@@ -920,6 +920,8 @@
     vifp->v_pkt_out   = 0;
     vifp->v_bytes_in  = 0;
     vifp->v_bytes_out = 0;
+    /* setup default IP ID */
+    vifp->v_ip_id = ip_initid();
 
     /* Adjust numvifs up if the vifi is higher than numvifs */
     if (V_numvifs <= vifcp->vifc_vifi)
@@ -2512,7 +2514,7 @@
     ip_outer->ip_tos = ip->ip_tos;
     if (ip->ip_off & htons(IP_DF))
 	ip_outer->ip_off |= htons(IP_DF);
-    ip_fillid(ip_outer);
+    ip_fillid(ip_outer, &vifp->v_ip_id);
     pimhdr = (struct pim_encap_pimhdr *)((caddr_t)ip_outer
 					 + sizeof(pim_encap_iphdr));
     *pimhdr = pim_encap_pimhdr;
Index: sys/netinet/ip_output.c
===================================================================
--- sys/netinet/ip_output.c
+++ sys/netinet/ip_output.c
@@ -175,7 +175,7 @@
 	if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) {
 		ip->ip_v = IPVERSION;
 		ip->ip_hl = hlen >> 2;
-		ip_fillid(ip);
+		ip_fillid(ip, (inp != NULL) ? &inp->inp_ip_id : NULL);
 		IPSTAT_INC(ips_localout);
 	} else {
 		/* Header already set, fetch hlen from there */
Index: sys/netinet/ip_var.h
===================================================================
--- sys/netinet/ip_var.h
+++ sys/netinet/ip_var.h
@@ -227,7 +227,8 @@
 void	ip_savecontrol(struct inpcb *, struct mbuf **, struct ip *,
 	    struct mbuf *);
 void	ip_slowtimo(void);
-void	ip_fillid(struct ip *);
+unsigned	ip_initid(void);
+void	ip_fillid(struct ip *, unsigned *);
 int	rip_ctloutput(struct socket *, struct sockopt *);
 void	rip_ctlinput(int, struct sockaddr *, void *);
 void	rip_init(void);
Index: sys/netinet/raw_ip.c
===================================================================
--- sys/netinet/raw_ip.c
+++ sys/netinet/raw_ip.c
@@ -510,7 +510,7 @@
 		 * but we got this limitation from the beginning of history.
 		 */
 		if (ip->ip_id == 0)
-			ip_fillid(ip);
+			ip_fillid(ip, &inp->inp_ip_id);
 
 		/*
 		 * XXX prevent ip_output from overwriting header fields.
Index: sys/netinet/sctp_output.c
===================================================================
--- sys/netinet/sctp_output.c
+++ sys/netinet/sctp_output.c
@@ -4106,7 +4106,7 @@
 				ip->ip_off = htons(0);
 			}
 			/* FreeBSD has a function for ip_id's */
-			ip_fillid(ip);
+			ip_fillid(ip, &inp->inp.inp_ip_id);
 
 			ip->ip_ttl = inp->ip_inp.inp.inp_ip_ttl;
 			ip->ip_len = htons(packet_length);
@@ -10950,7 +10950,7 @@
 		ip->ip_hl = (sizeof(struct ip) >> 2);
 		ip->ip_tos = 0;
 		ip->ip_off = 0;
-		ip_fillid(ip);
+		ip_fillid(ip, NULL);
 		ip->ip_ttl = MODULE_GLOBAL(ip_defttl);
 		if (port) {
 			ip->ip_p = IPPROTO_UDP;
Index: sys/netinet/sctp_pcb.c
===================================================================
--- sys/netinet/sctp_pcb.c
+++ sys/netinet/sctp_pcb.c
@@ -2458,6 +2458,9 @@
 	/* zap it */
 	bzero(inp, sizeof(*inp));
 
+	/* setup default IP ID */
+	inp->ip_inp.inp_ip_id = ip_initid();
+
 	/* bump generations */
 	/* setup socket pointers */
 	inp->sctp_socket = so;
Index: sys/netipsec/xform_ipip.c
===================================================================
--- sys/netipsec/xform_ipip.c
+++ sys/netipsec/xform_ipip.c
@@ -175,7 +175,7 @@
 		default:
 			goto nofamily;
 		}
-		ip_fillid(ipo);
+		ip_fillid(ipo, NULL);
 
 		otos = 0;
 		ip_ecn_ingress(ECN_ALLOWED, &otos, &itos);
Index: sys/netpfil/pf/if_pfsync.c
===================================================================
--- sys/netpfil/pf/if_pfsync.c
+++ sys/netpfil/pf/if_pfsync.c
@@ -214,6 +214,7 @@
 	uint32_t		sc_bulk_creatorid;
 	struct callout		sc_bulk_tmo;
 	struct callout		sc_bulkfail_tmo;
+	unsigned		sc_ip_id;	/* IP ID number */
 };
 
 #define	PFSYNC_LOCK(sc)		mtx_lock(&(sc)->sc_mtx)
@@ -298,6 +299,7 @@
 		return (EINVAL);
 
 	sc = malloc(sizeof(struct pfsync_softc), M_PFSYNC, M_WAITOK | M_ZERO);
+	sc->sc_ip_id = ip_initid();
 	sc->sc_flags |= PFSYNCF_OK;
 
 	for (q = 0; q < PFSYNC_S_COUNT; q++)
@@ -1538,7 +1540,7 @@
 	offset = sizeof(*ip);
 
 	ip->ip_len = htons(m->m_pkthdr.len);
-	ip_fillid(ip);
+	ip_fillid(ip, &sc->sc_ip_id);
 
 	/* build the pfsync header */
 	ph = (struct pfsync_header *)(m->m_data + offset);
Index: sys/netpfil/pf/pf_norm.c
===================================================================
--- sys/netpfil/pf/pf_norm.c
+++ sys/netpfil/pf/pf_norm.c
@@ -2273,7 +2273,7 @@
 	if (flags & PFRULE_RANDOMID && !(h->ip_off & ~htons(IP_DF))) {
 		uint16_t ip_id = h->ip_id;
 
-		ip_fillid(h);
+		ip_fillid(h, NULL);
 		h->ip_sum = pf_cksum_fixup(h->ip_sum, ip_id, h->ip_id, 0);
 	}
 }