ipv6 tunnel script

v6tunnel.sh

#!/bin/bash
old_ip=$(cat last_ip)
ip=$(dig +short googlerocks.dyndns.org)
echo $ip > last_ip

if [ "$ip" = "$old_ip" ]; then
    echo "nothing to do"
else
    echo "updating tunnel"
    ip tunnel del v6-tunnel
    ip tunnel add v6-tunnel mode sit remote $ip local 176.9.43.248 ttl 255
    ip link set v6-tunnel up
    ip addr add 2a01:4f8:150:54e3:abcd::1/80 dev v6-tunnel
    ip route add 2a01:4f8:150:5ff5::/64 dev v6-tunnel
    ip -f inet6 addr
fi
exit