Install and Configure Fail2ban on Fedora/CentOS/RedHat

The following is a very basic guide for setting up Fail2ban for SSH.

Install and basic config

Install Fail2ban

sudo dnf install fail2ban

You may need to install the epel repo

sudo yum install epel-release

Configure to run on system boot

sudo systemctl enable fail2ban

Start Fail2ban service

sudo systemctl start fail2ban

Copy config file with

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

Modify the config file

nano /etc/fail2ban/jail.local

Uncomment the following line and add any IPs that need to be whitelisted

ignoreip = 127.0.0.1/8 ::1 192.168.1.20

Save the file and restart Fail2Ban

sudo systemctl restart fail2ban

Configuring Fail2Ban for SSH

Create a new jail file in /etc/fail2ban/jail.d/ called sshd.local

nano /etc/fail2ban/fail.d/sshd.local

Add the following. Note: if you are using a custom ssh port, change “port = ssh” to “port = portnumber”

[sshd]
enabled = true
port = ssh
action = iptables-multiport
logpath = /var/log/secure
maxretry = 5
bantime = 300

Restart Fail2ban

sudo systemctl restart Fail2ban

You can list the firewall rules to verify that an IP gets banned.

iptables -S | grep ipaddress

Unbanning an IP Address

You can unban an IP address with the following command.

sudo fail2ban-client set sshd unbanip 192.168.1.100

You can check out the following link for more information

https://www.redhat.com/sysadmin/protect-systems-fail2ban

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