On 20 February 2002, Terry Shows said:
> Entries of the form
> host1.domain.com
> host2.domain.com
> Will cause an extreme slowdown at initial SMTP connection,
> BUT
> *.domain.com
> will not, and will give you the same results.
>
> Also, *ost1.domain.com will help you get it under grips for the one host,
> without slowing things down.
It's certainly believable that different patterns and search strings
will result in different DNS demands. But that shouldn't cause an
"extreme" slowdown -- unless you consider 2 or 3 seconds for a first
lookup "extreme". (That seems to be about the time it takes to do the
first couple of lookups after I restart my local DNS cache. After that,
most DNS requests go like greased lightning.) If DNS requests are
taking, say, 10s of seconds, then something is wrong with your local DNS
cache.
You might consider running dnscache (from DJBDNS) on your mail server.
See
http://cr.yp.to/djbdns.html .
Greg
--
Greg Ward - software developer gward@???
MEMS Exchange http://www.mems-exchange.org
