#!/bin/sh

ip tunnel add tun6to4 mode sit ttl 127 remote any local 82.227.12.18
ip link set dev tun6to4 up
ip -6 addr add ::82.227.12.18/16 dev tun6to4
# '82.227.12.18'.split('.').map { |i| i.to_i }.pack('C*').unpack('H*').first => "52e30c12"
ip -6 addr add 2002:52e3:0c12::1/16 dev tun6to4
ip -6 route add 2000::/3 via ::192.88.99.1 dev tun6to4 metric 1

# 6to4
iptables -I INPUT -p 41 -d 82.227.12.18 -j ACCEPT
iptables -A INPUT -p 41 -s 192.88.99.1 -j ACCEPT

# fw
ip6tables -F
ip6tables -X
ip6tables -P INPUT DROP
ip6tables -P OUTPUT ACCEPT
ip6tables -P FORWARD DROP
ip6tables -A INPUT -m state --state ESTABLISHED -j ACCEPT
ip6tables -A INPUT -p icmpv6 -j ACCEPT
ip6tables -A INPUT -i lo -j ACCEPT