Hi

I have a problem with our mail server where it sometimes take some of our users 30 seconds to connect to send/recieve mail and also somethimes connecting in FTP.

I understand this is due to our server is having a problem doing a
reverse lookup on the users IP address (usally people using ADSL have this problem). It seems a stange thing as if the reverse lookup fails it just times out after 30 seconds and let them connect.

Does anyone know how to stop this?

Nick

Server is a Linux Redhat 7.2 / send mail etc......

Is the reverse DNS of your server, from your server, correct?

[edited after rereading the initial post]

Try adding/changing the following line in your sendmail.cf

O Timeout.ident=0s

What ftp server are you running? If it's proftp you can add/change the following in you proftpd.conf.

UseReverseDNS off
IdentLookups off

Richard

Thanks for that, it seems to have sorted sending mail and the FTP but doesn't solve the problem that it takes a while for some people to connect to revieve mail (pop3).

It is definatly something to do with a person using a computer that is connected using a connection that uses NAT so there IP is hidden. Although not all people using NAT's seem to be affected.

Anyone got anymore ideas?

Thanks

Nick

If it's a DNS problem, may times you can work around it by using the IP address as your POP & SMTP servers.

I forgot a file :D

Change /etc/xinetd.d/ipop3 so that the following lines look like this:

log_on_success +=
log_on_failure +=

There should be nothing after the +=

Richard

For FTP, set:

IdentLookups off
UseReverseDNS off

In proftpd.conf

This should speed up login time.

cheers Noldar I think that might have fixed it : )