Traffic analysis and worldwide operation of open 6to4 relays for IPv6 deployment

The 6to4 method enables separate IPv6 sites to connect to the IPv6 Internet via a 6to4 relay router without an explicit IPv6-over-IPv4 tunnel setup. We have been operating a 6to4 relay router in Japan since March 2002, and started operating another relay router in the US from June 2003. This paper provides an analysis of IPv6 traffic through our 6to4 relay router. We also propose a method for controlling paths of the 6to4 communication, and clarify its effect by demonstrating it on our worldwide 6to4 network in Japan and the US.