[119181] in North American Network Operators' Group
Re: What DNS Is Not
daemon@ATHENA.MIT.EDU (Jack Bates)
Mon Nov 9 10:30:49 2009
Date: Mon, 09 Nov 2009 09:28:21 -0600
From: Jack Bates <jbates@brightok.net>
To: Alex Balashov <abalashov@evaristesys.com>
In-Reply-To: <4AF748B3.7060606@evaristesys.com>
Cc: NANOG list <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
Alex Balashov wrote:
> Thought-provoking article by Paul Vixie:
>
> http://queue.acm.org/detail.cfm?id=1647302
>
Bah, many of the CDN's I've dealt with don't seed geographical responses
based on DNS, but rather use many out of band methods for determining
what response they will hand out. The primary reason for short cutting
cache is to limit failures in case the system a requestor is going to
goes down.
And different CDN's behave differently, depending on how they deliver
content, support provider interconnects, etc. I'd hardly call many of
them DNS lies, as they do resolve you to the appropriate IP, and if that
IP disappears, try and quickly get you to another appropriate IP.
The rest of the article was informative,though.
Jack
