Re: [dnsext] RFC3596: A/AAAA records and additional section processing

The good news is that it is standard - section 3 of the same RFC says;

"3. Modifications to existing query types

   All existing query types that perform type A additional section
   processing, i.e., name server (NS), location of services (SRV) and
   mail exchange (MX) query types, must be redefined to perform both
   type A and type AAAA additional section processing.  These
   definitions mean that a name server must add any relevant IPv4
   addresses and any relevant IPv6 addresses available locally to the
   additional section of a response when processing any one of the above
   queries."

(e.g. dig MX example.stdlib.net @ns-191.awsdns-23.com.) .

The section you've quoted is just pointing out that a query for a
q-tuple of type AAAA would not normally by itself trigger any
additional-section processing. As worded, I think it's actually wrong.
A query of type AAAA might trigger additional section processing if
the query arrives at the parent of a delegated zone. For example the
query;

dig AAAA www.google.com @a.root-servers.net.

plainly does trigger additional section processing. (though one might
argue it was the name, not the type, that pulled the trigger).

2011/3/3 Jehan Pagès <jehan.marmottard@gmail.com>:
> Hi all,
>
> I have a small question about the IPv6 resource records extension (RFC3596).
> As section 2.3 states:
> « A type AAAA query does not trigger additional section processing. ». Fine.
>
> But I noticed that some DNS servers (like the one installed on my
> server, a bind 9.7.2) would return the A records in additional section
> on a AAAA query and AAAA records in additional on A queries.
> And when I thought about this, I realized it was a pretty good logics.
> Usually when people will try to contact a server, they will want both
> A and AAAA records.
> So the question is: why wouldn't this be standard?
> Thanks.
>
> Jehan
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-- 
Colm