I still don't understand why you run Redhat 9. Is there anything you run that won't work on a newer distro? Upgrading to Fedora 4 or 5 would allow you to upgrade just about everything to a more recent version and potentially increase security.

I would also like to echo Matir's post about iptables. You should definitely look into it.

Also, make sure you are using strong passwords. Dictionary attacks can be very successful these days.

Also, do your logfiles show you anything as to the method of intrusion? If we knew that, we could better help you harden your system for the future.

Just a final comment....go through unspawn's thread on the last page...his last thread...its very useful...

Also my 2 cents would be ... do it in this order

1.Get a FC5 distibution
2.Upgrade Rh-9 to FC5
3.Turn off all the services you dont need...(do this carefully)
4.Run pup overnight and update all your packages to the latest ones

Trust me...you are now 95% secure...

Finally bookmark this thread and come back to it whenever you have a problem...

The intruders are probably using some canned exploit to get into your network...there are loads available....

All the best...