More on CNAME problem

[Mark.Andrews at nominum.com]

> 
> In article <200009262115.e8QLFSu88729 at drugs.dv.isc.org>, 
> Mark.Andrews at nominum.com says...
> At 08:15 AM 09/27/2000 +1100, you wrote:
> >	Yes, as they are asking for a MX record immediately after which
> >	exists.
> >
> >	Mark
> ***************** REPLY SEPARATER ****************
> Yes you're right, there are many requests in the log file for "CNAME" records
>  
> only, some asking for "MX" records as well and some not. They seem to come fr
> om 
> very large sites. Why are they only asking for "CNAME" records, and what can 
> I 
> do to protect myself from those sites that don't like the answer or never 
> receive the answer?

	It's not that they don't like the answer or don't receive the
	answer.  They receive it and use it.  What isn't happening is
	that the negative answer is not being cached.  See RFC 2308.
	The MX record however is being cached which is why there are
	far fewer queries for the MX record.

	Mark
> 
> J.A. Coutts
> Systems Engineer
> Edsonet/TravPro
> 
> 
--
Mark Andrews, Nominum Inc.
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: Mark.Andrews at nominum.com