Re: 6to4 using ::FFFF:0000:0000/96 (mail.comcast.net AAAA record weirdness)

[Brian E Carpenter <brian.e.carpenter@gmail.com>]

On 2008-01-28 10:58, Florian Weimer wrote:
> * Brian E. Carpenter:
> 
>>> So, I think it's XP not doing the right thing here... XP should be
>>> selecting its own v4 stack instead of trying to shove packets to
>>> ::ffff:0:0/96 down 6to4... correct?
>> It seems to be a matter of taste which is the default.
> 
> Uhm, I think for a public anycast gateway (that's what we're talking
> about, right?), there's no other option than using the v4 stack instead.
> So the sane default seems clear to me.

I don't know any reason why one couldn't reach a NAT-PT via
an anycast-addressed 6to4 relay. The point is that we ended
up overloading the usage of the mapped-IPv4 prefix - not only
the sin of encoding semantics in the address bits, but also the
sin of doing so ambiguously. So no default can be "correct".
Probably local mapping to the IPv4 stack is slightly saner.

    Brian