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Re: [DNSOP] ANAME loop detection

Tony Finch <dot@dotat.at> Thu, 04 July 2019 15:37 UTC

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Date: Thu, 04 Jul 2019 16:37:53 +0100
From: Tony Finch <dot@dotat.at>
To: Jan Včelák <jv@fcelda.cz>
cc: dnsop <dnsop@ietf.org>
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Subject: Re: [DNSOP] ANAME loop detection
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Jan Včelák <jv@fcelda.cz> wrote:
>
> 2. QTYPE=ANAME: According to the current version of the draft, server
> answering to ANAME must include the ANAME and should include the
> sibling records. Let's modify the behavior and say the server should
> not (must not) include the sibling records. Then the server performing
> ANAME sibling address resolution could first query for ANAME before
> trying A or AAAA. We get the same loop detection mechanism as with
> CNAMEs at the cost of an extra query per ANAME

The main reason I thought it would be a good idea to include sibling
address records in ANAME responses was so that we could get a one-shot
address query as a side-effect. But I think we keep learning that it is a
bad idea to load too much stuff onto ANAME, so I think it's a reasonable
trade-off to ditch the addr query feature so that loop detection is
easier.

Tony.
-- 
f.anthony.n.finch  <dot@dotat.at>  http://dotat.at/
Isle of Man: West or southwest 3 or 4, becoming variable 2 at times. Smooth or
slight. Fair. Good.

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