In my opinion the best software is normally free and open source.. and CSF is a perfect example of this. CSF works in several different ways to secure your server.
1. It lets you open or close any ports you choose. If has a whitelist so you can close a port and then whitelist your IP and deny access to everyone but yourself. This is a double layer of security, as someone can’t crack your login if they can’t even get to it.
2. It has a service called LFD (login failure daemon) which monitors logs for failed logins and then blocks the suspect IP. You can configure the time frame and number of fails needed to block the IP.
3. Manual blocking of any IP you chose through a user friendly interface.
4. It can read an external deny file of your choice. This allows you to use a 3rd party spam service or even add custom code to your CMS of choice to block a member from the server.
This is just the tip of the iceburg, CSF has tons of features and settings for complete control. Here is the homepage: http://configserver.com/cp/csf.html
Discuss at the CSF Firewall Forum
