Carlos M. Martinez-Cagnazzo

If you use VmWare with Debian-based Linux guests (Debian, Ubuntu, etc.) you probably have been annoyed by the following behaviour: You copy / move your guest, or in my case, you boot your guest both from Windows and from Linux; next time you try to boot, you have no network.

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 es uno de los varios mecanismos de transicion de IPv4 a IPv6 que han sido propuestos por el IETF. Es un mecanismo de tunelizacion de IPv6 en un payload IPv4 con la caracteristica adicional de que el extremo remoto del tunel puede congurarse automaticamente ya que usa una direccion well-known como extremo remoto. Es facil de congurar y tiene buena performance. Sin embargo, presenta algunos desafíos a la hora de poderlo utilizar de manera estable detras de un NAT con IP publica variable, como es el caso de la inmensa mayoria de servicios ADSL hogarenos.