Config Server Firewall, also known as CSF, is a free firewall software used on Linux distributions. Except for the basic firewall functionality, it also offers IDS “intrusion detection system” as well as login and flood detection and other security features which help to keep your server secure.
CSF offers integration with popular web Control Panels such as cPanel, Directadmin, and Webmin. The LFD ( Login Failure Daemon ) also supports the following applications for monitoring login failures: openSSH, vsftpd, proftpd, pure-ftpd, Mod_security failures, and many others. In this tutorial, we will show you how to install Config Server Firewall (CSF) on Debian 11.