FYI - thought this would be of interest to some of you, there will be more news on this front shortly. http://www.comcast6.net/ 6to4 Relays Activated Tuesday, August 17, 2010 As we started our IPv6 trials, we began to observe an increase in 6to4 relay traffic. 6to4 is a transition mechanism built into some operating systems and home gateways. While it is not a transition technology that Comcast planned to invest in due to limitations related to performance, we did observe poor performance when 6to4 was used by our customers. In many cases, these customers were not even aware that 6to4 was enabled by default or that their device or operating system was attempting to use 6to4 to communicate with IPv6 resources on the Internet. In most cases, we observed that 6to4-enabled operating systems and devices were attempting to use a 6to4 relay infrastructure hosted by a midwestern university. In order to improve the Internet experience for Comcast customers who are using 6to4, whether knowingly or not, we have decided to operate 6to4 relays on a temporary, trial basis. Comcast has decided to deploy 6to4 relays in five locations around our network to improve performance and predictability, as compared to operating relays from a single location. These 6to4 relays are available via the standard 6to4 Anycast IP address, according to RFC 3068, which is 192.88.99.1. Devices attempting to use 6to4 within our network should automatically discover and utilize these new 6to4 relays, without end user intervention or configuration. The first pair of these relays was activated today. We plan to activate the remaining three within the next seven to ten days. We plan to monitor the performance of the 6to4 relays, to measure any beneficial effects resulting from adding these elements to our network. As our IPv6 trials evolve and we develop our plans for 2011 and beyond, we will assess our plans to support 6to4 moving forward. John ========================================= John Jason Brzozowski Comcast Cable e) mailto:john_brzozowski@cable.comcast.com w) http://www.comcast6.net =========================================