nanog mailing list archives

Re: What DNS Is Not


From: Glen Turner <gdt () gdt id au>
Date: Tue, 17 Nov 2009 13:01:41 +1030

On 10/11/09 01:58, Jack Bates wrote:
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.

It depends what you mean by "appropriate".  It may not be "least cost"
or "closest", and that can be a rude shock when the CDN traffic suddenly
costs you A$5/GB (delivered from the US by undersea cable) rather than
$0 (delivered from an in-country peer).

DNS is the wrong answer, simply because there's no way for the user to
express *their* policy.  But since there no CDN support in HTTP.....

--
 Glen Turner   <http://www.gdt.id.au/~gdt/>


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