Some ISP's having problem with my www subdomain

Barry Margolin barmar at alum.mit.edu
Fri Feb 27 05:15:15 UTC 2004


In article <c1mcbk$1un8$1 at sf1.isc.org>,
 Jeff Lasman <blists at nobaloney.net> wrote:

> Perfect? Will maybe to them.
> 
> For lucidsage.com they return a list of 20 congtiguous A records, all on 
> the same network.

That's because the zone name can't be a CNAME record, so they're forced 
to hard-code Akamai's IP addresses (with potential problems if Akamai 
renumbers their servers).

> For www.lucidsage.com they return two CNAME records, one to 
> geo.premiumservices.yahoo.com, and one to premium.geo.yahoo.akadns.net 
> (akami?).

It's not really two CNAME records, it's a chain of CNAMEs, which is 
permitted.  This looks like a reasonable, modular setup -- if Yahoo 
changes the company that they contract with to host their "Premium 
Services", they don't have to tell all their customers to update their 
CNAME records.  The customers point their aliases to something in the 
yahoo.com domain, and Yahoo points that name to the hosting vendor's 
domain.

There's extra overhead in the chain of CNAMEs.  But since Yahoo and 
Akamai are widely used hosting companies, I expect that these entries 
will often be found in caches, so the overhead is minimal.

-- 
Barry Margolin, barmar at alum.mit.edu
Arlington, MA


More information about the bind-users mailing list