Re: [DNSOP] draft-huston-kskroll-sentinel - naming format?

Tony Finch <dot@dotat.at> Tue, 31 October 2017 14:34 UTC

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Date: Tue, 31 Oct 2017 14:34:40 +0000
From: Tony Finch <dot@dotat.at>
To: Ray Bellis <ray@bellis.me.uk>
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Subject: Re: [DNSOP] draft-huston-kskroll-sentinel - naming format?
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Ray Bellis <ray@bellis.me.uk>; wrote:
> On 30/10/2017 17:40, Evan Hunt wrote:
>
> > IIRC we discussed it, and were concerned that _ta. could be cached as
> > nonexistent by servers implementing QNAME minimization.
>
> How would that happen, at least so long as _ta responds like any other
> empty non-terminal?

It's NXDOMAIN. (It'll also fall foul of RFCs 8020 and 8198.)

The problem occurs if you have a validator behind a cache. The cache will
prevent downstream id._ta. queries from reaching the root, so any
downstream trust anchor variation will be lost.

Tony.
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