Re: [DNSOP] Fundamental ANAME problems

Ray Bellis <ray@bellis.me.uk> Tue, 06 November 2018 18:36 UTC

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To: Tony Finch <dot@dotat.at>
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From: Ray Bellis <ray@bellis.me.uk>
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Subject: Re: [DNSOP] Fundamental ANAME problems
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On 06/11/2018 20:44, Tony Finch wrote:

> My understanding is that wildcards don't work for SRV because the
> _prefixes are used to disambiguate which service you are asking for,
> effectively to extend the RR TYPE number space. So if you wildcard a SRV
> record then the target port has to support every possible protocol :-)

No, it's because you can't do:

_http._tcp.*.example.com IN SRV ...

> If you are using an _prefix without any meaning of its own but only to
> move a record away from the apex (so that it can be delegated or CNAMEd)
> and also using a specific RR type or an RDATA prefix, then wildcards do
> not conflict.

I believe they still do, e.g.

_domainkey.*.example.com IN TXT ...

Ray