Content Delivery Networks

Crist Clark Crist.Clark at
Fri Aug 10 23:23:33 UTC 2007

>>> On 8/10/2007 at 11:55 AM, "Patrick W. Gilmore" <patrick at>

> On Aug 10, 2007, at 12:46 PM, John Levine wrote:
>>> Very interesting.  We've all heard and probably all passed along  
>>> that little
>>> bromide at one time or another.  Is it possible that at one time  
>>> it was true
>>> (even possibly for AOL) but with the rise of CDNs, policies of not 

>>> honoring
>>> TTL's have fallen by the wayside?
>> I think you'll still see it in spam zombies, some of which have the 

>> DNS info
>> pre-loaded into them in order to avoid split-horizon anti-spam  
>> techniques.
>> Not much we can do about that until we get sufficient backbone to
>> with the zombie problem and its software enablers.
> Actually, I think the fact Zombies do not honor TTLs is a feature.

Fast-flux my MX records to avoid spam? Throw the spammers'
technology back at 'em!

I changed some MX records in mid-July for a domain. Spam was
still flowing into the old MX hosts until I closed the firewall
25/tcp holes just today. Now just logging those zombies still
banging on the gates.

Crist J. Clark                              
crist.clark at
Globalstar Communications                                (408)

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