diff --git a/sys/net/if.c b/sys/net/if.c
index b21a126c6ca9..0b6db67811e8 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: if.c,v 1.269 2013/10/19 21:39:12 mrg Exp $	*/
+/*	$NetBSD: if.c,v 1.270 2014/01/02 18:29:01 pooka Exp $	*/
 
 /*-
  * Copyright (c) 1999, 2000, 2001, 2008 The NetBSD Foundation, Inc.
@@ -90,7 +90,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if.c,v 1.269 2013/10/19 21:39:12 mrg Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if.c,v 1.270 2014/01/02 18:29:01 pooka Exp $");
 
 #include "opt_inet.h"
 
@@ -1358,7 +1358,7 @@ if_link_state_change(struct ifnet *ifp, int link_state)
 	 * listeners would have an address and expect it to work right
 	 * away.
 	 */
-	if (link_state == LINK_STATE_UP &&
+	if (in6_present && link_state == LINK_STATE_UP &&
 	    old_link_state == LINK_STATE_UNKNOWN)
 		in6_if_link_down(ifp);
 #endif
@@ -1372,10 +1372,12 @@ if_link_state_change(struct ifnet *ifp, int link_state)
 #endif
 
 #ifdef INET6
-	if (link_state == LINK_STATE_DOWN)
-		in6_if_link_down(ifp);
-	else if (link_state == LINK_STATE_UP)
-		in6_if_link_up(ifp);
+	if (in6_present) {
+		if (link_state == LINK_STATE_DOWN)
+			in6_if_link_down(ifp);
+		else if (link_state == LINK_STATE_UP)
+			in6_if_link_up(ifp);
+	}
 #endif
 
 	splx(s);
@@ -1402,7 +1404,8 @@ if_down(struct ifnet *ifp)
 #endif
 	rt_ifmsg(ifp);
 #ifdef INET6
-	in6_if_down(ifp);
+	if (in6_present)
+		in6_if_down(ifp);
 #endif
 }
 
@@ -1431,7 +1434,8 @@ if_up(struct ifnet *ifp)
 #endif
 	rt_ifmsg(ifp);
 #ifdef INET6
-	in6_if_up(ifp);
+	if (in6_present)
+		in6_if_up(ifp);
 #endif
 }
 
@@ -1906,7 +1910,7 @@ ifioctl(struct socket *so, u_long cmd, void *data, struct lwp *l)
 
 	if (((oif_flags ^ ifp->if_flags) & IFF_UP) != 0) {
 #ifdef INET6
-		if ((ifp->if_flags & IFF_UP) != 0) {
+		if (in6_present && (ifp->if_flags & IFF_UP) != 0) {
 			int s = splnet();
 			in6_if_up(ifp);
 			splx(s);
diff --git a/sys/netinet/in_proto.c b/sys/netinet/in_proto.c
index 51320b4fa2a7..c8e2f7cfc516 100644
--- a/sys/netinet/in_proto.c
+++ b/sys/netinet/in_proto.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: in_proto.c,v 1.106 2013/06/05 19:01:26 christos Exp $	*/
+/*	$NetBSD: in_proto.c,v 1.107 2014/01/02 18:29:01 pooka Exp $	*/
 
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -61,7 +61,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: in_proto.c,v 1.106 2013/06/05 19:01:26 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: in_proto.c,v 1.107 2014/01/02 18:29:01 pooka Exp $");
 
 #include "opt_mrouting.h"
 #include "opt_inet.h"
@@ -200,7 +200,6 @@ const struct protosw inetsw[] = {
 	.pr_usrreq = tcp_usrreq,
 	.pr_init = tcp_init,
 	.pr_fasttimo = tcp_fasttimo,
-	.pr_slowtimo = tcp_slowtimo,
 	.pr_drain = tcp_drainstub,
 },
 {	.pr_type = SOCK_RAW,
diff --git a/sys/netinet/tcp_subr.c b/sys/netinet/tcp_subr.c
index af8acb8b94ad..b58e8bca73b9 100644
--- a/sys/netinet/tcp_subr.c
+++ b/sys/netinet/tcp_subr.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: tcp_subr.c,v 1.252 2013/11/23 14:20:21 christos Exp $	*/
+/*	$NetBSD: tcp_subr.c,v 1.253 2014/01/02 18:29:01 pooka Exp $	*/
 
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -91,7 +91,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: tcp_subr.c,v 1.252 2013/11/23 14:20:21 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: tcp_subr.c,v 1.253 2014/01/02 18:29:01 pooka Exp $");
 
 #include "opt_inet.h"
 #include "opt_ipsec.h"
@@ -104,6 +104,7 @@ __KERNEL_RCSID(0, "$NetBSD: tcp_subr.c,v 1.252 2013/11/23 14:20:21 christos Exp
 #include <sys/systm.h>
 #include <sys/malloc.h>
 #include <sys/mbuf.h>
+#include <sys/once.h>
 #include <sys/socket.h>
 #include <sys/socketvar.h>
 #include <sys/protosw.h>
@@ -241,10 +242,7 @@ struct	syn_cache_head tcp_syn_cache[TCP_SYN_HASH_SIZE];
 int	tcp_freeq(struct tcpcb *);
 
 #ifdef INET
-void	tcp_mtudisc_callback(struct in_addr);
-#endif
-#ifdef INET6
-void	tcp6_mtudisc_callback(struct in6_addr *);
+static void	tcp_mtudisc_callback(struct in_addr);
 #endif
 
 #ifdef INET6
@@ -387,35 +385,16 @@ struct mowner tcp_sock_rx_mowner = MOWNER_INIT("tcp", "sock rx");
 struct mowner tcp_sock_tx_mowner = MOWNER_INIT("tcp", "sock tx");
 #endif
 
-/*
- * Tcp initialization
- */
-void
-tcp_init(void)
+callout_t tcp_slowtimo_ch;
+
+static int
+do_tcpinit(void)
 {
-	int hlen;
 
 	in_pcbinit(&tcbtable, tcbhashsize, tcbhashsize);
 	pool_init(&tcpcb_pool, sizeof(struct tcpcb), 0, 0, 0, "tcpcbpl",
 	    NULL, IPL_SOFTNET);
 
-	hlen = sizeof(struct ip) + sizeof(struct tcphdr);
-#ifdef INET6
-	if (sizeof(struct ip) < sizeof(struct ip6_hdr))
-		hlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
-#endif
-	if (max_protohdr < hlen)
-		max_protohdr = hlen;
-	if (max_linkhdr + hlen > MHLEN)
-		panic("tcp_init");
-
-#ifdef INET
-	icmp_mtudisc_callback_register(tcp_mtudisc_callback);
-#endif
-#ifdef INET6
-	icmp6_mtudisc_callback_register(tcp6_mtudisc_callback);
-#endif
-
 	tcp_usrreq_init();
 
 	/* Initialize timer state. */
@@ -447,6 +426,38 @@ tcp_init(void)
 	tcpstat_percpu = percpu_alloc(sizeof(uint64_t) * TCP_NSTATS);
 
 	vtw_earlyinit();
+
+	callout_init(&tcp_slowtimo_ch, CALLOUT_MPSAFE);
+	callout_reset(&tcp_slowtimo_ch, 1, tcp_slowtimo, NULL);
+
+	return 0;
+}
+
+void
+tcp_init_common(unsigned basehlen)
+{
+	static ONCE_DECL(dotcpinit);
+	unsigned hlen = basehlen + sizeof(struct tcphdr);
+	unsigned oldhlen;
+
+	if (max_linkhdr + hlen > MHLEN)
+		panic("tcp_init");
+	while ((oldhlen = max_protohdr) < hlen)
+		atomic_cas_uint(&max_protohdr, oldhlen, hlen);
+
+	RUN_ONCE(&dotcpinit, do_tcpinit);
+}
+
+/*
+ * Tcp initialization
+ */
+void
+tcp_init(void)
+{
+
+	icmp_mtudisc_callback_register(tcp_mtudisc_callback);
+
+	tcp_init_common(sizeof(struct ip));
 }
 
 /*
diff --git a/sys/netinet/tcp_timer.c b/sys/netinet/tcp_timer.c
index 2f3add11edc8..596479f3b4d2 100644
--- a/sys/netinet/tcp_timer.c
+++ b/sys/netinet/tcp_timer.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: tcp_timer.c,v 1.86 2011/08/31 18:31:03 plunky Exp $	*/
+/*	$NetBSD: tcp_timer.c,v 1.87 2014/01/02 18:29:01 pooka Exp $	*/
 
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -93,7 +93,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: tcp_timer.c,v 1.86 2011/08/31 18:31:03 plunky Exp $");
+__KERNEL_RCSID(0, "$NetBSD: tcp_timer.c,v 1.87 2014/01/02 18:29:01 pooka Exp $");
 
 #include "opt_inet.h"
 #include "opt_tcp_debug.h"
@@ -230,13 +230,15 @@ tcp_delack(void *arg)
  * causes finite state machine actions if timers expire.
  */
 void
-tcp_slowtimo(void)
+tcp_slowtimo(void *arg)
 {
 
 	mutex_enter(softnet_lock);
 	tcp_iss_seq += TCP_ISSINCR;			/* increment iss */
 	tcp_now++;					/* for timestamps */
 	mutex_exit(softnet_lock);
+
+	callout_schedule(&tcp_slowtimo_ch, hz / PR_SLOWHZ);
 }
 
 /*
diff --git a/sys/netinet/tcp_var.h b/sys/netinet/tcp_var.h
index 1f2c66b31352..7c6f6ccd83d1 100644
--- a/sys/netinet/tcp_var.h
+++ b/sys/netinet/tcp_var.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: tcp_var.h,v 1.171 2013/11/12 09:02:05 kefren Exp $	*/
+/*	$NetBSD: tcp_var.h,v 1.172 2014/01/02 18:29:01 pooka Exp $	*/
 
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -912,6 +912,7 @@ void	 tcp_drain(void);
 void	 tcp_drainstub(void);
 void	 tcp_established(struct tcpcb *);
 void	 tcp_init(void);
+void	 tcp_init_common(unsigned);
 #ifdef INET6
 int	 tcp6_input(struct mbuf **, int *, int);
 #endif
@@ -935,6 +936,9 @@ void	 tcp_quench(struct inpcb *, int);
 void	 tcp6_quench(struct in6pcb *, int);
 #endif
 void	 tcp_mtudisc(struct inpcb *, int);
+#ifdef INET6
+void	 tcp6_mtudisc_callback(struct in6_addr *);
+#endif
 
 void	tcpipqent_init(void);
 struct ipqent *tcpipqent_alloc(void);
@@ -948,7 +952,8 @@ void	 tcp_setpersist(struct tcpcb *);
 int	 tcp_signature_compute(struct mbuf *, struct tcphdr *, int, int,
 	    int, u_char *, u_int);
 #endif
-void	 tcp_slowtimo(void);
+void	 tcp_slowtimo(void *);
+extern callout_t tcp_slowtimo_ch;
 void	 tcp_fasttimo(void);
 struct mbuf *
 	 tcp_template(struct tcpcb *);
diff --git a/sys/netinet/udp_usrreq.c b/sys/netinet/udp_usrreq.c
index b9494c6239c9..e873052ceee3 100644
--- a/sys/netinet/udp_usrreq.c
+++ b/sys/netinet/udp_usrreq.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: udp_usrreq.c,v 1.191 2013/11/23 14:20:21 christos Exp $	*/
+/*	$NetBSD: udp_usrreq.c,v 1.192 2014/01/02 18:29:01 pooka Exp $	*/
 
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -61,7 +61,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: udp_usrreq.c,v 1.191 2013/11/23 14:20:21 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: udp_usrreq.c,v 1.192 2014/01/02 18:29:01 pooka Exp $");
 
 #include "opt_inet.h"
 #include "opt_compat_netbsd.h"
@@ -73,6 +73,7 @@ __KERNEL_RCSID(0, "$NetBSD: udp_usrreq.c,v 1.191 2013/11/23 14:20:21 christos Ex
 #include <sys/param.h>
 #include <sys/malloc.h>
 #include <sys/mbuf.h>
+#include <sys/once.h>
 #include <sys/protosw.h>
 #include <sys/socket.h>
 #include <sys/socketvar.h>
@@ -225,24 +226,35 @@ EVCNT_ATTACH_STATIC(udp6_swcsum);
 
 static void sysctl_net_inet_udp_setup(struct sysctllog **);
 
-void
-udp_init(void)
+static int
+do_udpinit(void)
 {
 
-	sysctl_net_inet_udp_setup(NULL);
-
 	in_pcbinit(&udbtable, udbhashsize, udbhashsize);
 
 	MOWNER_ATTACH(&udp_tx_mowner);
 	MOWNER_ATTACH(&udp_rx_mowner);
 	MOWNER_ATTACH(&udp_mowner);
 
-#ifdef INET
+	return 0;
+}
+
+void
+udp_init_common(void)
+{
+	static ONCE_DECL(doudpinit);
+
+	RUN_ONCE(&doudpinit, do_udpinit);
+}
+
+void
+udp_init(void)
+{
+
+	sysctl_net_inet_udp_setup(NULL);
 	udpstat_percpu = percpu_alloc(sizeof(uint64_t) * UDP_NSTATS);
-#endif
-#ifdef INET6
-	udp6stat_percpu = percpu_alloc(sizeof(uint64_t) * UDP6_NSTATS);
-#endif
+
+	udp_init_common();
 }
 
 /*
diff --git a/sys/netinet/udp_var.h b/sys/netinet/udp_var.h
index 49c1306772c5..7d1c2f82065e 100644
--- a/sys/netinet/udp_var.h
+++ b/sys/netinet/udp_var.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: udp_var.h,v 1.38 2012/06/22 14:54:35 christos Exp $	*/
+/*	$NetBSD: udp_var.h,v 1.39 2014/01/02 18:29:01 pooka Exp $	*/
 
 /*
  * Copyright (c) 1982, 1986, 1989, 1993
@@ -92,6 +92,7 @@ extern	struct	inpcbtable udbtable;
 void	 *udp_ctlinput(int, const struct sockaddr *, void *);
 int	 udp_ctloutput(int, struct socket *, struct sockopt *);
 void	 udp_init(void);
+void	 udp_init_common(void);
 void	 udp_input(struct mbuf *, ...);
 int	 udp_output(struct mbuf *, ...);
 int	 udp_sysctl(int *, u_int, void *, size_t *, void *, size_t);
diff --git a/sys/netinet6/in6_proto.c b/sys/netinet6/in6_proto.c
index d48fe00fd06d..2ff834439d51 100644
--- a/sys/netinet6/in6_proto.c
+++ b/sys/netinet6/in6_proto.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: in6_proto.c,v 1.99 2013/06/05 19:01:26 christos Exp $	*/
+/*	$NetBSD: in6_proto.c,v 1.100 2014/01/02 18:29:01 pooka Exp $	*/
 /*	$KAME: in6_proto.c,v 1.66 2000/10/10 15:35:47 itojun Exp $	*/
 
 /*
@@ -62,7 +62,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: in6_proto.c,v 1.99 2013/06/05 19:01:26 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: in6_proto.c,v 1.100 2014/01/02 18:29:01 pooka Exp $");
 
 #include "opt_gateway.h"
 #include "opt_inet.h"
@@ -175,6 +175,15 @@ PR_WRAP_CTLINPUT(esp6_ctlinput)
 #define	esp6_ctlinput	esp6_ctlinput_wrapper
 #endif
 
+static void
+tcp6_init(void)
+{
+
+	icmp6_mtudisc_callback_register(tcp6_mtudisc_callback);
+
+	tcp_init_common(sizeof(struct ip6_hdr));
+}
+
 const struct ip6protosw inet6sw[] = {
 {	.pr_domain = &inet6domain,
 	.pr_protocol = IPPROTO_IPV6,
@@ -201,12 +210,9 @@ const struct ip6protosw inet6sw[] = {
 	.pr_ctlinput = tcp6_ctlinput,
 	.pr_ctloutput = tcp_ctloutput,
 	.pr_usrreq = tcp_usrreq,
-#ifndef INET	/* don't call initialization and timeout routines twice */
-	.pr_init = tcp_init,
+	.pr_init = tcp6_init,
 	.pr_fasttimo = tcp_fasttimo,
-	.pr_slowtimo = tcp_slowtimo,
 	.pr_drain = tcp_drainstub,
-#endif
 },
 {	.pr_type = SOCK_RAW,
 	.pr_domain = &inet6domain,
@@ -354,9 +360,17 @@ static const struct sockaddr_in6 in6_any = {
 	, .sin6_scope_id = 0
 };
 
+bool in6_present = false;
+static void
+in6_init(void)
+{
+
+	in6_present = true;
+}
+
 struct domain inet6domain = {
 	.dom_family = AF_INET6, .dom_name = "internet6",
-	.dom_init = NULL, .dom_externalize = NULL, .dom_dispose = NULL,
+	.dom_init = in6_init, .dom_externalize = NULL, .dom_dispose = NULL,
 	.dom_protosw = (const struct protosw *)inet6sw,
 	.dom_protoswNPROTOSW = (const struct protosw *)&inet6sw[sizeof(inet6sw)/sizeof(inet6sw[0])],
 	.dom_rtattach = rt_inithead,
diff --git a/sys/netinet6/in6_var.h b/sys/netinet6/in6_var.h
index c5017679cae7..6d7ae83594db 100644
--- a/sys/netinet6/in6_var.h
+++ b/sys/netinet6/in6_var.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: in6_var.h,v 1.66 2012/10/11 20:05:50 christos Exp $	*/
+/*	$NetBSD: in6_var.h,v 1.67 2014/01/02 18:29:01 pooka Exp $	*/
 /*	$KAME: in6_var.h,v 1.81 2002/06/08 11:16:51 itojun Exp $	*/
 
 /*
@@ -493,6 +493,7 @@ extern struct ifqueue ip6intrq;		/* IP6 packet input queue */
 extern const struct in6_addr zeroin6_addr;
 extern const u_char inet6ctlerrmap[];
 extern unsigned long in6_maxmtu;
+extern bool in6_present;
 
 /*
  * Macro for finding the internet address structure (in6_ifaddr) corresponding
diff --git a/sys/netinet6/udp6_usrreq.c b/sys/netinet6/udp6_usrreq.c
index 0df70b43a968..d6642d5ec93a 100644
--- a/sys/netinet6/udp6_usrreq.c
+++ b/sys/netinet6/udp6_usrreq.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: udp6_usrreq.c,v 1.91 2012/06/22 14:54:35 christos Exp $	*/
+/*	$NetBSD: udp6_usrreq.c,v 1.92 2014/01/02 18:29:01 pooka Exp $	*/
 /*	$KAME: udp6_usrreq.c,v 1.86 2001/05/27 17:33:00 itojun Exp $	*/
 
 /*
@@ -62,7 +62,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: udp6_usrreq.c,v 1.91 2012/06/22 14:54:35 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: udp6_usrreq.c,v 1.92 2014/01/02 18:29:01 pooka Exp $");
 
 #include "opt_inet.h"
 
@@ -123,6 +123,9 @@ udp6_init(void)
 {
 
 	sysctl_net_inet6_udp6_setup(NULL);
+	udp6stat_percpu = percpu_alloc(sizeof(uint64_t) * UDP6_NSTATS);
+
+	udp_init_common();
 }
 
 /*
diff --git a/sys/rump/net/lib/libnetinet/component.c b/sys/rump/net/lib/libnetinet/component.c
index f93b5f525839..6365c8a6b6ec 100644
--- a/sys/rump/net/lib/libnetinet/component.c
+++ b/sys/rump/net/lib/libnetinet/component.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: component.c,v 1.8 2013/08/14 09:55:05 pooka Exp $	*/
+/*	$NetBSD: component.c,v 1.9 2014/01/02 18:29:01 pooka Exp $	*/
 
 /*
  * Copyright (c) 2009 Antti Kantee.  All Rights Reserved.
@@ -28,7 +28,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: component.c,v 1.8 2013/08/14 09:55:05 pooka Exp $");
+__KERNEL_RCSID(0, "$NetBSD: component.c,v 1.9 2014/01/02 18:29:01 pooka Exp $");
 
 #include <sys/param.h>
 #include <sys/domain.h>
@@ -46,11 +46,10 @@ int carpattach(int);
 
 RUMP_COMPONENT(RUMP_COMPONENT_NET)
 {
-	extern struct domain arpdomain, inetdomain, inet6domain;
+	extern struct domain arpdomain, inetdomain;
 
 	DOMAINADD(arpdomain);
 	DOMAINADD(inetdomain);
-	DOMAINADD(inet6domain);
 
 	carpattach(1);
 }
diff --git a/sys/rump/net/lib/libnetinet6/component.c b/sys/rump/net/lib/libnetinet6/component.c
index 77846b8f8c60..f7aa371701e9 100644
--- a/sys/rump/net/lib/libnetinet6/component.c
+++ b/sys/rump/net/lib/libnetinet6/component.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: component.c,v 1.2 2013/08/14 09:55:05 pooka Exp $	*/
+/*	$NetBSD: component.c,v 1.3 2014/01/02 18:29:01 pooka Exp $	*/
 
 /*
  * Copyright (c) 2013 Antti Kantee.  All Rights Reserved.
@@ -26,7 +26,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: component.c,v 1.2 2013/08/14 09:55:05 pooka Exp $");
+__KERNEL_RCSID(0, "$NetBSD: component.c,v 1.3 2014/01/02 18:29:01 pooka Exp $");
 
 #include <sys/param.h>
 #include <sys/domain.h>
@@ -38,14 +38,12 @@ __KERNEL_RCSID(0, "$NetBSD: component.c,v 1.2 2013/08/14 09:55:05 pooka Exp $");
 #include "rump_private.h"
 #include "rump_net_private.h"
 
-#ifdef notyet
 RUMP_COMPONENT(RUMP_COMPONENT_NET)
 {
 	extern struct domain inet6domain;
 
 	DOMAINADD(inet6domain);
 }
-#endif
 
 RUMP_COMPONENT(RUMP_COMPONENT_NET_IFCFG)
 {