This might interest people who use FreeBSD and possibly other O/S's based on it like OSX. I have a gif0 tunnel to a SixXs pop and an ethernet interface called vr0. I have added one of the IP's from a /64 prefix to the vr0 interface. I wanted all traffic sourced from this server to come from that IP but as default it always came from the gif0 tunnel IP because of the rules of precedence for outgoing traffic. It's taken me a while but I now have a way of making this work. You need to deprecate the tunnel IP. Simply do this: ifconfig gif0 inet6 <your_tunnel_ip> deprecated Or in rc.conf: ipv6_ifconfig_gif0="<your tunnel ip> <the pops ip> prefixlen 128 deprecated" Then all outgoing traffic ignores this interface and sources traffic from the next available interface which in my case is the /64 subnet IP I have on vr0. Maybe something to add to the FAQ?