North American Network Operators Group
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Re: IPv6 routing /48s

  • From: Jack Bates
  • Date: Wed Nov 19 17:05:29 2008
Nathan Ward wrote:
The problem here is XPSP2/Vista assuming that non-RFC1918 = unfiltered/unNATed for the purposes of 6to4.
Well, deeper problem is that they're using 6to4 on an end host I suppose - it's supposed to be used on routers.


While I don't doubt that the 6to4 is broken in such circumstances, how many IPv6 content providers are using 6to4 addressing and not 2001:: addressing? 6to4 by default on xp and vista, in my experience, is only used if a) talking to another 6to4 address or b) there is no IPv4 address available.

6to4 never seemed like a viable method for content providing, though its use at the eyeball layer is somewhat iffy given that it's primary use is for other 6to4 addresses. If prefix policies are altered to use it for 2001:: addressing, problems start arising quickly.

A good example is that traceroutes through my he.net tunnel using 6to4 source addresses do not get replies through he.net's network, presumably due to their routers not being 6to4 aware and having no route to respond. Responses pick up again after picking up a network such as NTT that is 6to4 aware. My 2001:: addressing works just fine the entire route.

I'm sure there's quite a few networks that aren't 6to4 aware, hindering 6to4 connectivity to non-6to4 addresses.

Jack