Re: [DNSOP] Minimum viable ANAME

Ray Bellis <ray@bellis.me.uk> Tue, 06 November 2018 10:43 UTC

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From: Ray Bellis <ray@bellis.me.uk>
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Date: Tue, 6 Nov 2018 17:42:55 +0700
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Subject: Re: [DNSOP] Minimum viable ANAME
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On 06/11/2018 17:17, Tim Wicinski wrote:
> 
> In doing some digging through my data, I have instances which I have an 
> apex of a zone, sub zone, etc that are not HTTP but actually a dynamic 
> database endpoint.
> 
> I also have solid number of instances where the apex is used mainly as 
> an API endpoint, that serves not HTTP web content.

I think you're expressing a similar concern to those that Wes expressed 
at the mic.

However, if there was also an HTTP endpoint on that domain apex, how 
would you distinguish it from the non-HTTP one?   Clients don't connect 
to "hosts", they connect to "services" on those hosts.

Recalling Mark's message from last night which indirectly referenced RFC 
5507:

> People ... want a pointer to a server for a service at the apex.
> CNAME provided a pointer to a server when the prefix was www. 
> 
> This can be done a number of ways.
> 
> 1) Prefix  + name in rdata.
> 2) Service specific type + name in rdata > 3) Generic type + service and name in rdata.

#1 is what SRV does, but HTTP has issues with that
#2 is what my proposed HTTP record does
#3 is what SPF etc uses - TXT records with a prefix in the RDATA

These methods are not mutually exclusive - a prefixed SRV record can 
co-exist with an SPF TXT record and an HTTP (or other record) all at the 
same point in the DNS.

Turning my proposal into a supposedly "future proof" RR type as was 
suggested yesterday that covers non-HTTP "future services" won't work 
unless it uses a service prefix (#1) or something else in the RDATA 
(subtyping, #3) to identify the service.

Ray