ConfigServer Security & Firewall (CSF) is the most preferred, versatile, and effective firewall software for securing your servers. It is specifically designed to be compatible with panels such as cPanel/WHM, Plesk, and DirectAdmin on Linux-based servers. This article will explain in detail what CSF is, how to install it, how to use it, and why it is an indispensable security layer for your servers.

What is ConfigServer Security & Firewall (CSF)?

CSF is not just an iptables-based firewall, but also a security tool that offers many extra security features on your server. CSF stands out with the following features:

Advanced Firewall Management
Suspicious Login Detection (LFD - Login Failure Daemon)
DDOS Protection
Server Monitoring and Notification System
IP Blacklist / Whitelist Management
Panel Integrations (cPanel, DirectAdmin, Plesk, etc.)

How to Install CSF?

Installing CSF on your server is quite easy. You can quickly complete the installation by following the steps below.

Step 1: Connect Connect to your server as the root user via SSH:

ssh root@server_ip_address

Step 2: Install Required Packages

yum install perl-libwww-perl perl-Time-HiRes -y

On Ubuntu servers:

apt-get install libwww-perl liblwp-protocol-https-perl libio-socket-ssl-perl -y

Step 3: Download and Install CSF

cd /usr/src
git clone https://github.com/ConfigServer/csf.git
cd csf
sh install.sh

Step 4: Post-Installation Test

Check if the installation was successful:

perl /usr/local/csf/bin/csftest.pl

This command should output "RESULT: csf should function on this server".

Step 5: Activate CSF

csf -e

CSF Basic Settings

CSF settings are made from the /etc/csf/csf.conf file. Important basic settings:

TESTING = 0 Active firewall protection is provided by turning off the test mode.
RESTRICT_SYSLOG = 3 Protects server logs.
LF_EMAIL_ALERT = 1 Sends email notifications for suspicious login attempts.
CONNLIMIT Connection limits from an IP can be set.

Restarting CSF

csf -r

CSF Example Usages

Blocking an IP:

csf -d 192.168.1.1

Unblocking an IP:

csf -dr 192.168.1.1

Whitelisting an IP:

csf -a 192.168.1.1

Checking server status:

csf -l

FAQ (Frequently Asked Questions)

1. Is CSF paid? No, CSF is completely free firewall software.

2. Is CSF compatible with cPanel? Yes, CSF is fully compatible with cPanel/WHM. It can be easily managed from the WHM interface.

3. Does CSF provide DDOS protection? It provides small-scale DDOS protection; however, external protection systems should be preferred for large-scale DDOS attacks.

4. Is CSF alone sufficient on the server? No. CSF provides good basic protection; however, it is recommended to use additional software such as Imunify360 and ModSecurity.

Conclusion

ConfigServer Security & Firewall (CSF) is an indispensable tool for anyone who wants to increase server security. Whether you are managing a small website or a large company server, you can make your server more secure with CSF. With correct settings and regular monitoring, it will be possible to significantly increase the security level of your server.