How to Configure IPv6 Over IPv4 Tunnels

The best way to pass IPv6 packets over an IPv4 network is to use an automatic 6to4 tunnel. For instructions for implementing 6to4 routing at your site, refer to How to Configure a 6to4 Router.

1. Become superuser.

2. Create the file /etc/hostname6.ip.tunn. Use the values 0, 1, 2, and so on, for n. Then, add entries by following these steps.

   1. Add the tunnel source addresses. Then, add the tunnel destination addresses.

      tsrc IPv4-source-addr tdst IPv4-destination-addr up

   2. (Optional) Add a logical interface for the source and destination IPv6 addresses.

      addif IPv6-source-address IPv6-destination-address up

      Omit this step if you want the address autoconfigured for this interface. You do not need to configure link-local addresses for your tunnel. Link-local addresses are configured automatically.

When you finish configuring the tunnels, you must reboot.

You must perform the same steps at the other end of the tunnel for bidirectional communication to occur.

If your system is to be configured as a router, you must also configure your router to advertise over tunneling interfaces before rebooting. See How to Configure Your Router to Advertise Over Tunneling Interfaces.

Example—Entry for IPv6 Configuration File to Autoconfigure IPv6 Addresses

This example shows a tunnel for which all IPv6 addresses are autoconfigured.

tsrc 129.146.86.138 tdst 192.168.7.19 up

Example—Entry in the IPv6 Configuration File for Manually Configured Addresses

This example shows a tunnel for which global source and global destination addresses are manually configured. The site-local source and site-local destination addresses are also manually configured.

tsrc 120.46.86.138 tdst 190.68.7.19 up
addif fec0::1234:a00:fe12:528 fec0::5678:a00:20ff:fe12:1234 up
addif 2::1234:a00:fe12:528 2::5678:a00:20ff:fe12:1234 up