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

In message <AANLkTin_GMbCxTV8XTqMKM5RE=+3uwYSWp2Di_mBwZjU@mail.gmail.com>, =?IS
O-8859-1?Q?Colm_MacC=E1rthaigh?= writes:
> 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).

No. That is not addition section processing.  That is referral
processing.

Additional section processing would be returning A and AAAA to
NS queries.

> 2011/3/3 Jehan Pag=E8s <jehan.marmottard@gmail.com>:
> > Hi all,
> >
> > I have a small question about the IPv6 resource records extension (RFC359=
> 6).
> > As section 2.3 states:
> > =AB=A0A type AAAA query does not trigger additional section processing.=
> =A0=BB. 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
> > _______________________________________________
> > dnsext mailing list
> > dnsext@ietf.org
> > https://www.ietf.org/mailman/listinfo/dnsext
> >
> 
> 
> 
> -- =
> 
> Colm
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Mark Andrews, ISC
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