[dns-operations] Introducing CNAME Flattening: RFC-Compliant CNAMEs at a Domain's Root

David C Lawrence tale at akamai.com
Fri Apr 4 14:36:33 UTC 2014

Stephane Bortzmeyer writes:
> I was not able to find a real example: all the companies mentioned in
> the article as being happy users have their Web server at CloudFlare,
> where this service is useless.

I agree, it is a little peculiar, with their anycast HTTP servers.
You can see that some of these sites have www names that use a CNAME
intermediary, and conceivably they have configured their apex to use
that same CNAME with CloudFlare's flattening feature.  They're also
all giving me the same result from clients in both New England and
from Tokyo, so it does make it difficult to discern from the outside
that anything special is going on with an intermediary name.

Mark Andrews writes:
> 	Or one can add SRV or some other record that does the name
> 	to server mapping and not have to do all this behind the
> 	scenes stuff.

Lack of browser support is a big barrier to adoption here, and browser
vendors don't seem particularly eager to tackle it.  
is still in state New, and it was opened in 1999.

Me?  I love the vision of it, obviating hacks around the apex CNAME
restriction, but it just isn't practical right now.  People
like the econsultancy.com CTO quoted in the article have a problem
with wanting to brand their sites without www (as you yourself
indicated was an issue in your draft back in 2002).  Resolving the
CNAME internally solves their problem and works with existing

Bring me a world in which SRV for HTTP without location bar
redirection is commonplace, and we'd be happy to encourage its use.

Anthony Eden writes:
> While CloudFlare did not give any credit to previous work done
> (which sort of pisses me off, but whatever), they are essentially
> implementing the same thing that Amazon did with their ALIAS
> implementation, the same thing that we did with the DNSimple ALIAS
> implementation, and the same thing that DNSMadeEasy did with ANAME
> records.

FWIW Akamai has been doing it since 2003, but I don't feel
particularly put off that they didn't itemize how their competitors
do similar things.

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