[dns-operations] Reporting glue as authoritive data -- Bug!

Mark Andrews Mark_Andrews at isc.org
Tue Jan 29 02:20:58 UTC 2008


> 
> > * Matt Larson:
> > 
> > > On Fri, 25 Jan 2008, Paul Vixie wrote:
> > >> BIND9 does what the RFC says,
> > >
> > > Chapter and verse, please.  I believe this situation is not cut and
> > > dry according to an RFC, but I am more than willing to be enlightened.
> > 
> > I've also seen the answers Lutz described from BIND 9 servers, so I'm
> > a bit puzzled, too.
> 
> 	
> 	RFC 1034.
> 
>    3. Start matching down, label by label, in the zone.  The
>       matching process can terminate several ways:
> 
> 	You leave the zone when you hit the NS RRset at bottom of
> 	zone.  3b reinforces this statement.  Glue is below the
> 	zone.  
> 
>          b. If a match would take us out of the authoritative data,
>             we have a referral.  This happens when we encounter a
>             node with NS RRs marking cuts along the bottom of a
>             zone.
> 
> 	RFC 2181 also has a retriction about promoting additional
> 	records (glue) to the answer section.

	Say you have a delegation for sub.example.net like

	ns.sub.example.net A 1.2.3.4
	sub.example.net NS ns.sub.example.net

	Match down label by label you try ".", "net.", "example.net."
	"sub.example.net." at which point you process the query as
	per 3b.  You never see ns.sub.example.net.

	Mark

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



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