Unix Review > UnixReview.com > Tool of the Month: DenyHosts
Dedicated server users, if you are running Linux you should consider this and portsentry and shorewall as the best combination start. But, the rpm is hard to install. I got it working on one Mandriva 2005 LE webserver, but a Fedora dedicated server I maintain still refuses to work with it. So, I will get it working with the tarball.
This is a very simple (simlistic) list of basic security for Linux servers on the web.
AllowUsers in /etc/ssh/sshd_config for only allowed users
secure passwords for said users
change default port for webmin to something other than 10000
shorewall's basic setup should work pretty well right out of the box.
Our company specializes in network security and Open Source solutions. Maybe we can help.