• This script uses the route2 method; make sure that the iproute2 package is installed.

As root, write the following rc.d init script to /etc/rc.d/6in4-tunnel:

#!/bin/bash

### begin user configuration

##############################################
#                                            #
#  Stop this script before you reconfigure!  #
#                                            #
##############################################

# if_name     - interface name that is to be created for the 6in4 link
if_name=6in4

# server_ipv4 - ipv4 address of the server that is providing the 6in4 tunnel
server_ipv4=127.0.0.1

# client_ipv4 - ipv4 address of the client that is receiving the 6in4 tunnel
client_ipv4=127.0.0.1

# client_ipv6 - ipv6 address of the client 6in4 tunnel endpoint
client_ipv6=2001:feed:face:beef::2/64

# link_mtu    - set the mtu for the 6in4 link
link_mtu=1480

# tunnel_ttl  - set the ttl for the 6in4 tunnel
tunnel_ttl=64

### end user configuration

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

    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

    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

You will need to provide your 6in4 link configuration between the following sections of /etc/rc.d/6in4-tunnel:

### begin user configuration

### end user configuration

Once /etc/rc.d/6in4-tunnel has been configured properly, give it permission to be executed:

# chmod +x /etc/rc.d/6in4-tunnel

To create the 6in4 tunnel link and bring up the interface:

# /etc/rc.d/6in4-tunnel start

To delete the 6in4 tunnel link and remove the interface:

# /etc/rc.d/6in4-tunnel stop

The following method allows /etc/rc.d/6in4-tunnel to start automatically at system startup.

• Verify that the 6in4 tunnel link is configured and working properly before doing this!

As root, insert 6in4-tunnel right after network in the DAEMONS line of /etc/rc.conf.

After this addition, the DAEMONS line in /etc/rc.conf should look something like this:

...

#
# -----------------------------------------------------------------------
# DAEMONS
# -----------------------------------------------------------------------
#
# Daemons to start at boot-up (in this order)
#   - prefix a daemon with a ! to disable it
#   - prefix a daemon with a @ to start it up in the background
#
DAEMONS=(syslog-ng iptables ip6tables network 6in4-tunnel openntpd ...

...