Re: draft-wbeebee-ipv6-cpe-router-03

[james woodyatt <jhw@apple.com>]

On Nov 19, 2008, at 16:41, Brian E Carpenter wrote:
> Sure, but it is not sure that the 6to4 path is symmetric - the
> reply packets might come from a completely different relay.

It's impossible to test all the possible reverse paths that might ever  
be used, but a test to see whether the node at the 6to4 anycast  
address is actually a router running a functioning 6to4 relay is a  
worthwhile test for a CPE router to perform.

I don't think it's strictly necessary to shut down all IPv6 routing  
just because the anycast 6to4 relay isn't responding, because you can  
still reach all the other 6to4 sites over encapsulated direct IPv4,  
but it's certainly an exception condition worthy of asynchronous  
notification to a network manager... however that's done in the  
residential CPE environment.  (Apple has a proprietary method for  
doing that, but one could imagine specifying an SNMP trap message, for  
example.)


--
james woodyatt <jhw@apple.com>
member of technical staff, communications engineering