diff --git a/lib/tun.c b/lib/tun.c
index 8325f5d..11ea7bc 100644
--- a/lib/tun.c
+++ b/lib/tun.c
@@ -1,6 +1,7 @@
 /* 
  * TUN interface functions.
  * Copyright (C) 2002, 2003, 2004 Mondru AB.
+ * Copyright (C) 2017 by Harald Welte <laforge@gnumonks.org>
  * 
  * The contents of this file may be used under the terms of the GNU
  * General Public License Version 2, provided that the above copyright
@@ -37,16 +38,17 @@
 #include <sys/socket.h>
 #include <errno.h>
 #include <net/route.h>
+#include <net/if.h>
 
 #if defined(__linux__)
-#include <linux/if.h>
 #include <linux/if_tun.h>
 #include <linux/netlink.h>
 #include <linux/rtnetlink.h>
 
 #elif defined (__FreeBSD__)
-#include <net/if.h>
 #include <net/if_tun.h>
+#include <net/if_var.h>
+#include <netinet/in_var.h>
 
 #elif defined (__APPLE__)
 #include <net/if.h>
@@ -65,8 +67,13 @@
 #include "tun.h"
 #include "syserr.h"
 
+static int tun_setaddr4(struct tun_t *this, struct in_addr *addr,
+			struct in_addr *dstaddr, struct in_addr *netmask);
+
 #if defined(__linux__)
 
+#include <linux/ipv6.h>
+
 int tun_nlattr(struct nlmsghdr *n, int nsize, int type, void *d, int dlen)
 {
 	int len = RTA_LENGTH(dlen);
@@ -247,7 +254,7 @@
 	struct msghdr msg;
 
 	if (!this->addrs)	/* Use ioctl for first addr to make ping work */
-		return tun_setaddr(this, addr, dstaddr, netmask);
+		return tun_setaddr4(this, addr, dstaddr, netmask);
 
 	memset(&req, 0, sizeof(req));
 	req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifaddrmsg));
@@ -345,7 +352,7 @@
 
 	/* TODO: Is this needed on FreeBSD? */
 	if (!this->addrs)	/* Use ioctl for first addr to make ping work */
-		return tun_setaddr(this, addr, dstaddr, netmask);	/* TODO dstaddr */
+		return tun_setaddr4(this, addr, dstaddr, netmask);	/* TODO dstaddr */
 
 	memset(&areq, 0, sizeof(areq));
 
@@ -391,7 +398,7 @@
 #elif defined (__sun__)
 
 	if (!this->addrs)	/* Use ioctl for first addr to make ping work */
-		return tun_setaddr(this, addr, dstaddr, netmask);
+		return tun_setaddr4(this, addr, dstaddr, netmask);
 
 	SYS_ERR(DTUN, LOGL_ERROR, errno,
 		"Setting multiple addresses not possible on Solaris");
@@ -403,9 +410,8 @@
 
 }
 
-int tun_setaddr(struct tun_t *this,
-		struct in_addr *addr,
-		struct in_addr *dstaddr, struct in_addr *netmask)
+static int tun_setaddr4(struct tun_t *this, struct in_addr *addr,
+			struct in_addr *dstaddr, struct in_addr *netmask)
 {
 	struct ifreq ifr;
 	int fd;
@@ -498,13 +504,112 @@
 	tun_sifflags(this, IFF_UP | IFF_RUNNING);
 
 #if defined(__FreeBSD__) || defined (__APPLE__)
-	tun_addroute(this, dstaddr, addr, netmask);
+	tun_addroute(this, dstaddr, addr, &this->netmask);
 	this->routes = 1;
 #endif
 
 	return 0;
 }
 
+static int tun_setaddr6(struct tun_t *this, struct in6_addr *addr, struct in6_addr *dstaddr,
+			size_t prefixlen)
+{
+	struct in6_ifreq ifr;
+	int fd;
+
+	memset(&ifr, 0, sizeof(ifr));
+
+#if defined(__linux__)
+	ifr.ifr6_prefixlen = prefixlen;
+	ifr.ifr6_ifindex = if_nametoindex(this->devname);
+	if (ifr.ifr6_ifindex == 0) {
+		SYS_ERR(DTUN, LOGL_ERROR, 0, "Error getting ifindex for %s\n", this->devname);
+		return -1;
+	}
+#elif defined(__FreeBSD__) || defined (__APPLE__)
+	strncpy(ifr.ifr_name, this->devname, IFNAMSIZ);
+#endif
+
+	/* Create a channel to the NET kernel */
+	if ((fd = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
+		SYS_ERR(DTUN, LOGL_ERROR, 0, "socket() failed");
+		return -1;
+	}
+
+#if defined(__linux__)
+	if (addr) {
+		memcpy(&this->addr, addr, sizeof(*addr));
+		memcpy(&ifr.ifr6_addr, addr, sizeof(*addr));
+		if (ioctl(fd, SIOCSIFADDR, (void *) &ifr) < 0) {
+			if (errno != EEXIST) {
+				SYS_ERR(DTUN, LOGL_ERROR, 0, "ioctl(SIOCSIFADDR) failed");
+			} else {
+				SYS_ERR(DTUN, LOGL_NOTICE, 0, "ioctl(SIOCSIFADDR): Address alreadsy exists");
+			}
+			close(fd);
+			return -1;
+		}
+	}
+
+#if 0
+	/* FIXME: looks like this is not possible/necessary for IPv6? */
+	if (dstaddr) {
+		memcpy(&this->dstaddr, dstaddr, sizeof(*dstaddr));
+		memcpy(&ifr.ifr6_addr, dstaddr, sizeof(*dstaddr));
+		if (ioctl(fd, SIOCSIFDSTADDR, (caddr_t *) &ifr) < 0) {
+			SYS_ERR(DTUN, LOGL_ERROR, "ioctl(SIOCSIFDSTADDR) failed");
+			close(fd);
+			return -1;
+		}
+	}
+#endif
+
+#elif defined(__FreeBSD__) || defined (__APPLE__)
+	if (addr)
+		memcpy(&ifr.ifr_ifru.ifru_addr, addr, sizeof(ifr.ifr_ifru.ifru_addr));
+	if (dstaddr)
+		memcpy(&ifr.ifr_ifru.ifru_dstaddr, dstaddr, sizeof(ifr.ifr_ifru.ifru_dstaddr));
+
+	if (ioctl(fd, SIOCSIFADDR_IN6, (struct ifreq *)&ifr) < 0) {
+		SYS_ERR(DTUN, LOGL_ERROR, 0, "ioctl(SIOCSIFADDR_IN6) failed");
+		close(fd);
+		return -1;
+	}
+#endif
+
+	close(fd);
+	this->addrs++;
+
+	/* On linux the route to the interface is set automatically
+	   on FreeBSD we have to do this manually */
+
+	/* TODO: How does it work on Solaris? */
+
+	tun_sifflags(this, IFF_UP | IFF_RUNNING);
+
+#if 0	/* FIXME */
+//#if defined(__FreeBSD__) || defined (__APPLE__)
+	tun_addroute6(this, dstaddr, addr, prefixlen);
+	this->routes = 1;
+#endif
+
+	return 0;
+}
+
+int tun_setaddr(struct tun_t *this, struct in46_addr *addr, struct in46_addr *dstaddr, size_t prefixlen)
+{
+	struct in_addr netmask;
+	switch (addr->len) {
+	case 4:
+		netmask.s_addr = htonl(0xffffffff << (32 - prefixlen));
+		return tun_setaddr4(this, &addr->v4, dstaddr ? &dstaddr->v4 : NULL, &netmask);
+	case 16:
+		return tun_setaddr6(this, &addr->v6, dstaddr ? &dstaddr->v6 : NULL, prefixlen);
+	default:
+		return -1;
+	}
+}
+
 int tun_route(struct tun_t *this,
 	      struct in_addr *dst,
 	      struct in_addr *gateway, struct in_addr *mask, int delete)
diff --git a/lib/tun.h b/lib/tun.h
index c50bdf9..1cd0767 100644
--- a/lib/tun.h
+++ b/lib/tun.h
@@ -1,6 +1,7 @@
 /* 
  * TUN interface functions.
  * Copyright (C) 2002, 2003 Mondru AB.
+ * Copyright (C) 2017 by Harald Welte <laforge@gnumonks.org>
  * 
  * The contents of this file may be used under the terms of the GNU
  * General Public License Version 2, provided that the above copyright
@@ -12,6 +13,8 @@
 #ifndef _TUN_H
 #define _TUN_H
 
+#include "../lib/in46_addr.h"
+
 #define PACKET_MAX      8196	/* Maximum packet size we receive */
 #define TUN_SCRIPTSIZE   256
 #define TUN_ADDRSIZE     128
@@ -66,8 +69,8 @@
 extern int tun_addaddr(struct tun_t *this, struct in_addr *addr,
 		       struct in_addr *dstaddr, struct in_addr *netmask);
 
-extern int tun_setaddr(struct tun_t *this, struct in_addr *our_adr,
-		       struct in_addr *his_adr, struct in_addr *net_mask);
+extern int tun_setaddr(struct tun_t *this, struct in46_addr *our_adr,
+		       struct in46_addr *his_adr, size_t prefixlen);
 
 int tun_addroute(struct tun_t *this, struct in_addr *dst,
 		 struct in_addr *gateway, struct in_addr *mask);