How To Install Fail2Ban on CentOS 7

In this tutorial, we will show you how to install Fail2Ban on CentOS 7. For those of you who didn’t know, Fail2ban is a security-based application for your Unix-based server. The fail2ban service is commonly used to protect your SSH and FTP from the unauthorized connections. Fail2ban runs as a daemon that uses python scripts to parse log files for system intrusion attempts and adds custom rules to Iptables configuration files to ban access to certain IP addresses.

This article assumes you have at least basic knowledge of Linux, know how to use the shell, and most importantly, you host your site on your own VPS. The installation is quite simple and assumes you are running in the root account, if not you may need to add ‘sudo‘ to the commands to get root privileges. I will show you through the step-by-step installation fail2ban in CentOS 7 server.

Prerequisites

• A server running one of the following operating systems: CentOS 7.
• It’s recommended that you use a fresh OS install to prevent any potential issues.
• SSH access to the server (or just open Terminal if you’re on a desktop).
• A non-root sudo user or access to the root user. We recommend acting as a non-root sudo user, however, as you can harm your system if you’re not careful when acting as the root.

Install Fail2Ban on CentOS 7

Step 1. First, you need to enable the EPEL repository on your system.

## RHEL/CentOS 7 64-Bit ##
# wget http://dl.fedoraproject.org/pub/epel/7/x86_64/e/epel-release-7-5.noarch.rpm
# rpm -ivh epel-release-7-5.noarch.rpm

Step 2. Install Fail2Ban.

Install Fail2Ban with the following command:

yum install -y fail2ban

Start the service and make it start automatically every time you reboot your server:

systemctl enable fail2ban
systemctl start fail2ban

Configure Fail2Ban

Step 3. Setup a Fail2ban default configuration.

cp /etc/fail2ban/jail.conf /etc/fail2ban/jail.local

Now, you will see the default section with some basic rules that are followed by fail2ban itself. If you want to add some extra layer of protection to your server, then you can customize each rule section as per your needs. There are few lines that act as a basic setup you can edit as necessary to suit your need including ignoreip, bantime, findtime, and maxretry. You can read what each line means in the explanation available there.

[DEFAULT]

# "ignoreip" can be an IP address, a CIDR mask or a DNS host. Fail2ban will not
# ban a host which matches an address in this list. Several addresses can be
# defined using space separator.
ignoreip = 127.0.0.1

# "bantime" is the number of seconds that a host is banned.
bantime = 600

# A host is banned if it has generated "maxretry" during the last "findtime"
# seconds.
findtime = 600

# "maxretry" is the number of failures before a host get banned.
maxretry = 3

Now restart Fail2ban so the new configuration can take effect:

systemctl restart fail2ban.service

Congratulations! You have successfully installed fail2ban. Thanks for using this tutorial for installing fail2ban to protect SSH in CentOS 7 system. For additional help or useful information, we recommend you check the official fail2ban website.