IPv6 tunnel broker setup

Hurricane Electric offers a free tunnel broker service that is relatively painless to use under Arch if you wish to add IPv6 connectivity to an IPv4-only host.

These instructions work for SixXS tunnels as well.

Registering for a tunnel

It is not that hard to do. Feel free to fill in the directions here if something seems tricky, but otherwise just go the tunnel broker site and complete the registration.

Tunnel rc.d script

For this script to work you will need the iproute2 package installed:

# pacman -S iproute2

Try the following init script to start and stop an IPv6 tunnel once you have registered it with HE. I placed this at /etc/rc.d/6in4-tunnel. Obviously some of the variables up top will need to be filled in.

For DSL users the link_mtu should be set to 1472

#!/bin/bash

if_name=he6in4

# "Server IPv4 Address" under "IPv6 Tunnel Endpoints" on HE tunnel details page
server_ipv4=''

# Your local IP. NOTE: when behind a NAT (even with DMZ),
# use an address of your LOCAL machine, NOT the ROUTER one.
client_ipv4=''

# Your HE-assigned client IP, "Client IPv6 Address" on HE tunnel details page
client_ipv6=''

link_mtu=1480
tunnel_ttl=255

daemon_name=6in4-tunnel

. /etc/rc.conf
. /etc/rc.d/functions

case "$1" in
  start)
    stat_busy "Starting $daemon_name daemon"

    ifconfig $if_name &>/dev/null
    if [ $? -eq 0 ]; then
      stat_busy "Interface $if_name already exists"
      stat_fail
      exit 1
    fi

    # Note from Lekensteyn: removing "local $client_ipv4" seems to work too!
    ip tunnel add $if_name mode sit remote $server_ipv4 local $client_ipv4 ttl $tunnel_ttl
    ip link set $if_name up mtu $link_mtu
    ip addr add $client_ipv6 dev $if_name
    ip route add ::/0 dev $if_name
    # Here is how you would add additional ips....which should be on the eth0 interface
    # ip addr add 2001:XXXX:XXXX:beef:beef:beef:beef:1/64 dev eth0
    # ip addr add 2001:XXXX:XXXX:beef:beef:beef:beef:2/64 dev eth0
    # ip addr add 2001:XXXX:XXXX:beef:beef:beef:beef:3/64 dev eth0

    add_daemon $daemon_name
    stat_done
    ;;

  stop)
    stat_busy "Stopping $daemon_name daemon"

    ifconfig $if_name &>/dev/null
    if [ $? -ne 0 ]; then
      stat_busy "Interface $if_name does not exist"
      stat_fail
      exit 1
    fi

    ip link set $if_name down
    ip tunnel del $if_name

    rm_daemon $daemon_name
    stat_done
    ;;

  *)
    echo "usage: $0 {start|stop}"
esac
exit 0

Start tunnel at boot time

Once you have that all setup how you want you will need to add 6in4-tunnel to your /etc/rc.conf file:

DAEMONS=(... 6in4-tunnel ...)

Using the tunneling with dynamic IPv4 IP

The simplest way of using tunelling with a dynamic IPv4 IP is to set up a cronjob that is going to periodically update your current address. To do that open crontab -e and add, in a new line:

*/10 * * * * wget -O /dev/null https://USERNAME:PASSWORD@ipv4.tunnelbroker.net/ipv4_end.php?tid=TUNNELID >> /dev/null 2>&1

Which should also make wget quiet and not bothering you with emails about its activity. Please replace USERNAME, PASSWORD and TUNNELID by the details of your account and tunnel. I would recommend running the command on its own first, to check if it works. To do that run:

wget https://USERNAME:PASSWORD@ipv4.tunnelbroker.net/ipv4_end.php?tid=TUNNELID