In message <20081024084140.GA92276@netch.kiev.ua>, Valentin Nechayev writes:
> Hi,
>
> Fri, Oct 24, 2008 at 08:59:20, Mark_Andrews wrote about "Re: glue records in
> child zone":
>
> > Except it isn't authoritative. It is GLUE.
> >
> > When you query for a zone's NS RRset there is no need to
> > return any additional records.
> >
> > The time when additional records are necessary is when there
> > is a referral. At all other time additional records are
> > completely optional.

>
> OK, understood. But there is another question for this case. In the
> initial example, query of address of ns1.hq.example.org from NS of
> example.org gives only referral response to NSes of hq.example.org, in
> spite of record for ns1.hq.example.org is present in the example.org
> zone itself. Am I correct that presence of NSes of hq.example.org is
> enough to treat by modern named that `hs1.hq.example.org A' shall be
> ignored during learning of contents of example.org?


Not returned on direct query. I can be returned in a referral.

> If yes, why f.gtld-servers.net knows IP address of c.gtld-servers.net
> and authoritatively tells it in response to direct query?


Because the Atlas servers are based on old code and because
there are delegations that only work in COM and NET because
the servers promote glue to answer.

Mark
--
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742 INTERNET: Mark_Andrews@isc.org