How to Install Fail2Ban on Centos 9

Fail2Ban is a powerful security tool that protects your CentOS 9 server by blocking IPs that show suspicious or malicious behavior.

Step 1: Update Your System

Keeping your system updated ensures Fail2Ban installs smoothly and runs on the latest secure packages.

sudo dnf update -y

Step 2: Install EPEL Repository

Fail2Ban is available through the EPEL repository, so you must enable it before installation.

sudo dnf install epel-release -y

Step 3: Install Fail2Ban

Once the EPEL repo is enabled, you can install Fail2Ban directly using the package manager.

sudo dnf install fail2ban fail2ban-firewalld -y

Step 4: Start and Enable Fail2Ban Service

Enabling and starting the service ensures Fail2Ban launches automatically and actively monitors your server.

sudo systemctl enable --now fail2ban

Step 5: Create a Local Configuration File

Creating a local configuration file ensures your Fail2Ban settings remain safe during updates and allows you to manage security rules in a clean and organized way.

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

Edit the file to customize protection:

sudo nano /etc/fail2ban/jail.local

Step 6: Enable SSH Jail

Enabling the SSH jail helps prevent brute-force login attempts on your server.

sudo bash -c 'echo -e "[sshd]\nenabled = true" >> /etc/fail2ban/jail.local'

Step 7: Restart Fail2Ban to Apply Changes

Restarting Fail2Ban is necessary to load your updated configuration and ensure all new security rules take effect properly.

sudo systemctl restart fail2ban

Step 8: Verify Fail2Ban Status

Checking the status confirms Fail2Ban is running correctly and protecting your server.

sudo fail2ban-client status

Step 9: Check SSH Jail Status

This command shows how many IPs are banned and ensures the SSH jail is active.

sudo fail2ban-client status sshd