[153538] in North American Network Operators' Group
Re: AAAA's for www.netflix.com
daemon@ATHENA.MIT.EDU (Daniel Roesen)
Thu Jun 7 22:24:13 2012
Date: Fri, 8 Jun 2012 04:23:33 +0200
From: Daniel Roesen <dr@cluenet.de>
To: nanog@nanog.org
Mail-Followup-To: nanog@nanog.org
In-Reply-To: <20120608021120.31A0C215D5AB@drugs.dv.isc.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Fri, Jun 08, 2012 at 12:11:20PM +1000, Mark Andrews wrote:
> > $ dig @pdns3.ultradns.org www.netflix.com. A +norec +short
> > wwwservice--frontend-313423742.us-east-1.elb.amazonaws.com.
> > $ dig @pdns3.ultradns.org www.netflix.com. AAAA +norec +short
> > dualstack.wwwservice--frontend-313423742.us-east-1.elb.amazonaws.com.
> > $ dig @pdns3.ultradns.org www.netflix.com. ANY +short +norec
> > $
> >
> > Resolving www.netflix.com using ANY RRtype fails with an empty answer
> > section in the DNS response.
>
> Which is just plain BROKEN.
Yup.
> > This DNS trickery seems to be from the "taking a shower, trying not
> > to get wet" department. And has adverse effects in corner cases. While
> > playing around, I had periods of time where I couldn't resolve the FQDN
> > at all, possibly due some caching of the empty response.
>
> It's not DNS trickery.
The "trickery" is returning different CNAMEs for QTYPE=A and QTYPE=AAAA.
I'm not sure what's the goal of that is, but it's 4am here so I have an
excuse of not seeing the light. :)
Best regards,
Daniel
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