Mine

root@OpenWrt:~# cat /etc/init.d/sixxs
#!/bin/sh /etc/rc.common
# Copyright (C) 2006 OpenWrt.org
START=90

start() {
        ip tunnel add sixxs mode sit local 24.226.26.139 remote 216.93.250.26
        ip link set sixxs up
        ip link set mtu 1280 dev sixxs
        ip tunnel change sixxs ttl 64

        #My sixxs.net gateway address
        ip -6 addr add  2001:4830:1100:1f::2/64 dev sixxs
        ip -6 route add default via 2001:4830:1100:1f::1 dev sixxs

        # My subnet
        ip -6 addr add 2001:4830:110c::/64 dev br-lan
        ip -6 route add 2000::/3 via 2001:4830:1100:1f::1 dev sixxs
        }

stop() {
        ip link set sixxs down
        ip -6 route del 2000::/3 via 2001:4830:1100:1f::1 dev sixxs
        ip -6 route del default via 2001:4830:1100:1f::1 dev sixxs
        ip tunnel del sixxs
        }