What is ConfigServer Firewall?
This suite of scripts provides:
Straight-forward SPI iptables firewall script
Daemon process that checks for login authentication failures for:
Courier imap, Dovecot, uw-imap, Kerio
openSSH
cPanel, WHM, Webmail (cPanel servers only)
Pure-ftpd, vsftpd, Proftpd
Password protected web pages (htpasswd)
Mod_security failures (v1 and v2)
Suhosin failures
Exim SMTP AUTH
Custom login failures with separate log file and regular expression matching
POP3/IMAP login tracking to enforce logins per hour
SSH login notification
SU login notification
Excessive connection blocking
UI Integration for cPanel, DirectAdmin and Webmin
Easy upgrade between versions from within cPanel/WHM, DirectAdmin or Webmin
Easy upgrade between versions from shell
Pre-configured to work on a cPanel server with all the standard cPanel ports open
Pre-configured to work on a DirectAdmin server with all the standard DirectAdmin ports open
Auto-configures the SSH port if it's non-standard on installation
Block traffic on unused server IP addresses - helps reduce the risk to your server
Alert when end-user scripts sending excessive emails per hour - for identifying spamming scripts
Suspicious process reporting - reports potential exploits running on the server
Excessive user processes reporting
Excessive user process usage reporting and optional termination
Suspicious file reporting - reports potential exploit files in /tmp and similar directories
Directory and file watching - reports if a watched directory or a file changes
Block traffic on the DShield Block List and the Spamhaus DROP List
BOGON packet protection
Pre-configured settings for Low, Medium or High firewall security (cPanel servers only)
Works with multiple ethernet devices
Server Security Check - Performs a basic security and settings check on the server (via cPanel/DirectAdmin/Webmin UI)
Allow Dynamic DNS IP addresses - always allow your IP address even if it changes whenever you connect to the internet
... and much much more. See website.
DeePizza added ConfigServer Firewall as alternative to SSHGuard, IPBanPro and Fail2ban
Comments and Reviews
CSF (ConfigServer Security and Firewall) is honestly one of those tools that just works and does its job really well. If you’re managing servers, it’s probably one of the first things you’ll want to set up for security. It’s straightforward, powerful, and gets the job done without a lot of fuss.
The best thing about CSF is how much it handles for you. Whether it’s blocking sketchy IPs, rate-limiting connections, or keeping an eye on failed logins, it covers a lot of bases. It integrates nicely with iptables, so you don’t have to mess with raw firewall rules too much. Plus, it plays well with popular control panels like cPanel and DirectAdmin, which is super handy if you’re using one of those.
What I really like is that it’s not a pain to set up. Sure, there are a ton of options you can tweak if you want, but the defaults are solid enough to get you started right away. The config file is well-documented, so it’s not hard to figure out what’s going on if you need to make adjustments. And if you ever run into an issue, the community support is great—chances are someone else has already dealt with it and posted a solution.
Performance-wise, CSF doesn’t hog resources, which is a big deal. You can run it on a busy server without worrying that it’s going to slow things down. It’s also nice that it’s actively maintained—updates roll out regularly, and the developers seem to stay on top of new threats.
A shoutout to LFD (Login Failure Daemon) too—it’s like having a watchdog that alerts you the moment someone’s trying to brute-force their way into your server. It’s saved me a few headaches more than once.
If you’re looking for something reliable to lock down your server without turning it into a full-time job, CSF is a no-brainer. It’s simple, effective, and does what you need it to do without any drama.