Comcast enables 6to4 relays

Mitchell Warden wardenm at
Tue Aug 31 06:22:03 UTC 2010

> The list seems to be showing relays that announce both the IPv4 and the 
> IPv6 anycast prefixes.
> I have noticed a number of deployments that announce the (in)famous IPv4 
> prefix and then consider their deployment complete. I suspect that there 
> is a lack of 2002::/16 announcements and this would be contributing to 
> the regular problems with return paths.
> Obviously the IPv6 content networks benefit the most from having a relay 
> translating back to IPv4.
> Anyone have experience with this?
> -- 
> Graham Beneke

Is there a reason not to advertise more specific prefixes from 2002::/16 to ensure that traffic for your v4 routes comes back to your own 6to4 router?

If for example all my users have v4 addresses in, I could advertise 2002:C002:0000::/40 instead of or in addition to the full 2002::/16.


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