How to Install CSF on Ubuntu 22.04

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Config Server Firewall is a free and advanced firewall for most Linux distributions and Linux based VPS. It provides a comprehensive set of tools to protect your system, including advanced firewall rules, intrusion detection, and login failure detection.

Pre-requisites

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• A system with Ubuntu 22.04 installed and running.

• root access to the system.

Update the System

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Run the below command to ensure your system is up-to-date,

apt update -y

apt upgrade -y

Install required packages

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CSF requires some Perl modules to work correctly. Install them using the below command,

apt install -y libwww-perl libcrypt-ssleay-perl libio-socket-ssl-perl

Download and install CSF

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Next download and install CSF. The below commands will retrieve the latest version of CSF, extract it, and start the installation,

cd /tmp
wget https://download.configserver.com/csf.tgz
tar -xzf csf.tgz
cd csf
sudo ./install.sh

Configure CSF

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Once CSF is installed, you can configure it to your needs. The main configuration file for CSF is located at /etc/csf/csf.conf.

You can use any text editor to modify it, in our case we are using nano editing,

nano /etc/csf/csf.conf

In this file, you can make any changes like ports are open, in our case we'll remove SSH port from CSF,

Remove the 22 from TCP_IN as below,

# Allow incoming TCP ports

TCP_IN = "20,21,22,25,53,80,110,143,443,465,587,853,993,995,2077,2078,2079,2080,2082,2083,2086,2087,2095,2096,8443"

Allow outgoing TCP ports

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TCP_OUT = "20,21,22,25,37,43,53,80,110,113,443,587,853,873,993,995,2086,2087,2089,2703"

#### Start CSF 

After configuring CSF, start the firewall using the following command:

    csf -s

Use the below command to reload the CSF,

    csf -ra

If everything is working correctly, you can enable CSF and put it into active mode using below command,

    csf -e

That's it! You have now installed and configured CSF on Ubuntu 22.04