Carlos M. Martinez-Cagnazzo

6to4 is one of the many transition mechanisms proposed by the IETF to ease the move towards an IPv6 internet. It is a tunneling protocol which encapsulates IPv6 packets in the payload of an IPv4 packet, with the added feature that the remote endpoint (the 6to4 Relay) of the tunnel configures itself automatically and uses a well-known anycast IPv4 address.

6to4 is easy to setup and gives near-native performance depending on how near you are to a 6to4 relay. However, it presents some challenges when used behind a dynamic IP NAT box, which is the case of the vast majority of home ADSL/Cable broadband services.

In this paper (in Spanish yet only, sorry!) we introduce 6to4 and how to configure it in a Linux box, and we also present a script that configures 6to4 and maintains it working by tracking the IPv4 changes in time. Additionally, using the stateless autoconfiguration daemon radvd it is possible to connect a whole LAN to the IPv6 internet.

Note: This is still a work in progress, the script having being tried only on Ubuntu and Debian.