Re: [DNSOP] new ANAME draft: draft-hunt-dnsop-aname-00.txt

Florian Weimer <fweimer@redhat.com> Thu, 13 April 2017 11:30 UTC

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To: Peter van Dijk <peter.van.dijk@powerdns.com>, dnsop <dnsop@ietf.org>
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From: Florian Weimer <fweimer@redhat.com>
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Date: Thu, 13 Apr 2017 13:30:12 +0200
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Archived-At: <https://mailarchive.ietf.org/arch/msg/dnsop/CiWPj1I844YYlQqVYOPRftRZ10c>
Subject: Re: [DNSOP] new ANAME draft: draft-hunt-dnsop-aname-00.txt
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On 04/12/2017 09:06 PM, Peter van Dijk wrote:
> On 12 Apr 2017, at 10:21, Florian Weimer wrote:
> 
>> SRV wouldn't work anyway because it is incompatible with existing name 
>> resolution interfaces anyway.
> 
> Which browsers tend to avoid as far as I know, but it’s besides the 
> point - browsers are not doing SRV and we have to accept that.

If the browser uses DNS directly, it won't be able to use NIS/LDAP, 
WINS, Bonjour, or LLDNS.

Firefox on GNU/Linux uses getaddrinfo, as expected.

>> If you do not insist on using SRV, but something that is just an alias 
>> (like PTR, ANAME etc.) and processed in the client, it would be quite 
>> straightforward to put this into the stub resolver, and then all 
>> applications[*] would automatically get the addresses at the 
>> substitution name (SNAME).  Disallow multiple substitution names per 
>> owner name and their chaining (but chaining to CNAME would be okay), 
>> and I think it would just work.
> 
> But that’s a forklift upgrade of -end user stations-.

It's just about an optimization.  I think it's doable, except that we'd 
receive pushback on the query load issue.

>> But then DNS operators will worry about a 50% (from A/AAAA to 
>> A/AAAA/SNAME) to 150% (from A/AAAA to A/AAAA/SNAME plus A/AAAA at the 
>> SNAME) increase in query load.  (SRV would be worse because there 
>> could be multiple target names, all needing separate processing.) 
>> Would that be acceptable?  I don't know.
> 
> I don’t know either - I do know the draft does not require anyone 
> (except the auth operator who decides to use ANAME) to do more queries 
> than they are doing now.

Right, that's one advantage of the ANAME proposal.

Florian