Re: [dnsext] Some thoughts on the updated aliasing draft

Suzanne Woolf <> Sun, 27 March 2011 22:11 UTC

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Date: Sun, 27 Mar 2011 22:13:19 +0000
From: Suzanne Woolf <>
To: Ted Hardie <>
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Subject: Re: [dnsext] Some thoughts on the updated aliasing draft
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On Sun, Mar 27, 2011 at 11:35:59AM +0200, Ted Hardie wrote:
> So, just to restate this for my own jet-lagged benefit:  the client hands a
> name to the DNS and gets back the information that it's a pointer to a
> canonical name, along with the data required to synthesize other names ("You
> asked for "  All names under and including
> are cannonically at or under").  So
> the application could get back "Here's the data for
>; the requested you handed me returned a pointer to
> here".  If it doesn't understand that , it gets the data at the record
> stored at
> Does this match what you're thinking?

I think so, but I may well not be quite this smart :-)

The two cases are "I understand the pointer and can do my own
synthesis, give me all you got" and "I can't understand the pointer"
and the server does the synthesis. In the first case, the application
sees that the name it asked for was a pointer, and gets the rest of
the set of associated names; in the second, it doesn't know and
presumably doesn't care, but has no access to the rest of the names or
the knowledge that they're associated together.

The question I think I was asking was whether the application might
sometimes prefer the simple answer, and not see the pointer or the
other names. 

I'd like an answer along the lines of "Nope, it's always OK and
sometimes preferred to expose the full complexity and let the
application sort it out." But, you tell me.