Re: [DNSOP] Where in a CNAME chain is the QNAME?

Stephane Bortzmeyer <bortzmeyer@nic.fr> Sun, 25 September 2016 15:52 UTC

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Date: Sun, 25 Sep 2016 11:06:02 +0000
From: Stephane Bortzmeyer <bortzmeyer@nic.fr>
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Subject: Re: [DNSOP] Where in a CNAME chain is the QNAME?
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On Fri, Sep 23, 2016 at 07:57:26PM +0000,
 Viktor Dukhovni <ietf-dane@dukhovni.org> wrote 
 a message of 73 lines which said:

> This would I believe cause problems if one then concludes that the
> subtree below the QNAME is absent.

For the record, I agree with Robert Edmonds: this case is well covered
in the current draft-ietf-dnsop-nxdomain-cut-05, with the concept of
"denied name" (which is often, but not always, the QNAME).

> So the NXDOMAIN for "truth" in the first query definitely does not
> preclude a "stranger" subtree under "truth".  It only attests to the
> non-existence of "fiction".
> 
> IIRC, reading a long-ago discussion on this topic, Paul Vixie, for
> one, seemed to say that the first NXDOMAIN response is not only
> acceptable, but is in fact the more correct choice.

Yes, and it has been settled some time ago, with RFC 6604.