Re: [dbound] draft-brotman-rdbd

"Niall O'Reilly" <> Thu, 09 May 2019 19:06 UTC

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From: "Niall O'Reilly" <>
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Subject: Re: [dbound] draft-brotman-rdbd
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On 9 May 2019, at 17:42, John Levine wrote:

> For over 30 years the only place anyone has used PTR records has been
> in the rDNS trees under and

Catalog zones are much more recent, and specifically use PTR records.
I'm aware that support for these is a BIND-specific feature,
and utterly unaware of how much it's being used.

> I think that if
> you try to use them anywhere else, you'll find way too much software
> that has baked in assumptions that they don't belong there.

I'm not sure what kind of software might have such assumptions
baked in.  The very small sample that my provisioning chain includes
(Emacs, dnssec-signzone, nsd, unbound, zonemaster) shows no problem
of this kind.

One significant counterexample is enough, of course.

I have a strong suspicion that any provisioning chain needing
modification to accommodate innovative uses of PTR would also need
work to add support for the new RRtypes proposed in the draft, and
that the effort involved in either case might be roughly commensurate.

> Note that RFC 1035 says they "are used in special domains".

A domain that has a special relationship with another domain is
arguably "special".  IIUC, advertising such a relationship is the
purpose of the new RRtypes proposed in the draft.

I'm still coloured "unconvinced".