[155144] in North American Network Operators' Group
Re: Is Hotmail in the habit of ignoring MX records?
daemon@ATHENA.MIT.EDU (Michael J Wise)
Fri Jul 27 22:31:20 2012
From: Michael J Wise <mjwise@kapu.net>
In-Reply-To: <50134302.2010800@tiggee.com>
Date: Fri, 27 Jul 2012 19:30:40 -0700
To: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Jul 27, 2012, at 6:40 PM, David Miller wrote:
> MX records don't "chain".
But they do, "Expand".
And I can think of a way whereby if an MX record referenced itself, =
*AND* included something extra =85 (did you see the something extra?)
That it would be possible (and I'm not saying this is what is happening, =
but =85 it could be) =85
That an internal process could go resolving MX records, and adds them =
all to an internal table, until it figures it's got 'em all=85
"Gotta Get 'Em All!"
=85 and maybe, just maybe =85 it exhausts the table space, and gives up, =
and tries the A record.
I'm not saying this would be "Standard".
I'm not saying this is the best, or perhaps even an acceptable way to do =
it.
Or that it is in fact what is happening.
But the config looked weird, and I can imagine =85 a system being =
written as described =85 and breaking just this way given that MX =
configuration.
I can imagine Test =85 not catching it.
Aloha,
Michael.
--=20
"Please have your Internet License =20
and Usenet Registration handy..."
