Re: [DNSOP] Questions on draft-ietf-dnsop-delegation-only

Joe Abley <> Thu, 30 July 2020 18:05 UTC

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From: Joe Abley <>
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Date: Thu, 30 Jul 2020 14:05:02 -0400
Cc: Petr Špaček <>,
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To: Paul Wouters <>
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Subject: Re: [DNSOP] Questions on draft-ietf-dnsop-delegation-only
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Hi Paul,

On 30 Jul 2020, at 13:20, Paul Wouters <> wrote:

> On Thu, 30 Jul 2020, Petr Špaček wrote:
>> It is hard to see what benefits draft-ietf-dnsop-delegation-only brings without having description of "DNSSEC Trasparency" mechanism available.
> I do not believe that is correct. The first and foremost purpose is for
> the bit to signal the parent zone's behaviour in a public way that
> prevents targeted / coerced attacks from the parent. This allows
> policy violations to be rejected even if these violating DNS answers
> are DNSSEC signed.

Has anybody done a survey to find out how many TLD zones actually fits the description of "delegation-only"?

I know for a fact that ORG does not today and I would say is unlikely ever to. For example, any nameserver N that is subordinate to domain D and linked to some other domain E will be served authoritatively from the ORG zone if domain D is suspended and while E continues to be delegared. Suspensions happen regularly, e.g. for domains implicated in technical abuse. There are several thousand examples of such N today and history suggests the number is not becoming smaller. Even if the number of such N could reach zero in ORG, we could never assume the number would remain at zero and still would not be able to assert usefully that the zone is delegation-only.

I don't think ORG is particularly special in this regard; it seems possible that other (possibly many other; possibly most or all) TLD zones are similar. If there are no TLD zones that actually are delegation-only then there seems no obvious application for it, regardless of whether we consider it to be useful or not.