[cobalt-users] nslookup, PTR's and slow responses...

[Brian Rahill <cobalt@xxxxxxxxxxxxxxxxxxxxxxx>]

Hi all,

I've got a client who complains about slow response and timeouts using 
SMTP.  I've extensively searched the archives and have localized the 
problem to the fact that the Raq 4r is doing an nslookup on his firewall IP 
address however there is no PTR defined for his firewall.  So he has to 
wait for the lookup to timeout before the connection is completed.  It 
looks like the timeout is about 10 seconds (i.e. if I try an nslookup on 
his IP it times out in about 10 seconds), but he complains that it takes 
nearly a minute to connect.

So no I have a few questions:

1. Does the Raq do reverse lookups for every connection?  It doesn't appear 
to do it for POP and likely not for HTTP.

2. Is there an easy way to disable nslookups and/or shorten the 
timeout?  Is this a bad thing to do?

3. Do most *nix machines do reverse lookups or is this a cobalt specific 
thing? (he's complaining that this is the only machine he has had trouble 
with).

Thanks in advance!

Brian