I wrote a howto a while back on how to setup windows vista with a ipv6 tunnel to tunnelbroker.net – this post can be found here http://larmeir.com/?p=354 . To follow up on this I host a Debian etch 5.0 server in my office that I use for troubleshooting network connections and as a backup system for my webserver. Below is how I setup the ipv6 tunnel:

#ip tunnel add he-ipv6 mode sit remote my.tunnel.broker.ip local 192.168.1.8 ttl 255
#ip link set he-ipv6 up
#ip addr add 2001:470:1f0e:4ee::2/64 dev he-ipv6
# ip route add ::/0 dev he-ipv6
#ip -f inet6 addr

Also, dont forget to check that the ipv6 kernel module is loaded:

~# lsmod | grep ipv6
ipv6                  235364  31 sit

If not then load it:

# modprobe ipv6

then test it :)

~# ping6 -c4 ipv6.google.com
PING ipv6.google.com(vx-in-x68.google.com) 56 data bytes
64 bytes from vx-in-x68.google.com: icmp_seq=1 ttl=56 time=116 ms
64 bytes from vx-in-x68.google.com: icmp_seq=2 ttl=56 time=117 ms
64 bytes from vx-in-x68.google.com: icmp_seq=3 ttl=56 time=116 ms
64 bytes from vx-in-x68.google.com: icmp_seq=4 ttl=56 time=116 ms

— ipv6.google.com ping statistics —
4 packets transmitted, 4 received, 0% packet loss, time 3011ms
rtt min/avg/max/mdev = 116.301/116.750/117.440/0.429 ms

Hopefully this will help somone with Debian when trying to get a ipv6 tunnel setup.