[Pdns-users] CNAME extra balast for DNS server ?

bert hubert ahu at ds9a.nl
Tue Aug 31 06:08:37 UTC 2004

On Wed, Aug 25, 2004 at 06:20:44PM +0200, Lorens Kockum wrote:

> Assuming the same TTLs for both configurations, it will increase
> the traffic by the amount of lookups on "mail.domeinnaam.nl",
> because when the result is a CNAME, the CNAME will have to be
> resolved.  That shouldn't be a problem, though. The alternative
> is to keep

Indeed, and it is not a problem. If you run with thousands of queries per
second you might notice this. 

> HOWEVER! Bear in mind that a cname is an alias...
> for everything! That means that mail adressed to
> user at mail.domeinnaam.nl may be rewritten to user at pop.axess.nl.
> Postfix does it.  This is usually *not* what people want, and a
> good reason for totally avoiding cnames.

CNAMES are powerful things which easily allow you to mess things up, indeed. 

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