dynamic ipip6 tunnel setup script

tun-setup.sh

#!/bin/sh

TAP=tap0 # the IPv6 interface which, in my case, is a tap device
TUN=tun0 # the tunnel interface you are about to create

# address @ tap
REMOTE= # your server's address goes here
LOCAL=`ifconfig $TAP | grep inet6 | grep -v fe80 | head -1 | awk '{print $3}'`

# address @ tun
TUN_REMOTE=10.7.0.1
TUN_LOCAL=10.7.0.2

if [ -z $LOCAL ]; then
	exit 1 # no ipv6 address
fi

ping -c1 -w1 $TUN_REMOTE
if [ $? == 0 ]; then
	exit 1 # already connected
fi

sleep 10

ssh $REMOTE "
  ip -6 tunnel del $TUN
  ip -6 tunnel add $TUN mode ipip6 remote $LOCAL local $REMOTE
  ifconfig $TUN $TUN_REMOTE pointopoint $TUN_LOCAL
"

ip -6 tunnel del $TUN
ip -6 tunnel add $TUN mode ipip6 remote $REMOTE local $LOCAL
ifconfig $TUN $TUN_LOCAL pointopoint $TUN_REMOTE

ip route add 8.8.8.8 via $TUN_REMOTE
# and more routes...