fail2ban is an intrusion prevention framework written in Python that protects Linux systems and servers from brute-force attacks.

monitor the strength and frequency of attacks.

can be setup to block IP addresses automatically based on specific paramenters.

1. Install

sudo apt install fail2ban

2. enable

sudo systemctl enable fail2ban-service

3. config

ls -al /etc/fail2ban

jail.conf file

should create a local jail: /etc/fail2ban/jail.local (not overwritten if fail2ban is updated)

sudo cp jail.conf jail.local
enabled = false # change to true and restart service
port = ssh
#make fail2ban look after the sshd service
filter = sshd
logpath = /var/log/auth.log
#security option
#number of attempts allowed
maxretry = 3
bantime = 3600
#while list ip address (be cafeful not to look yourself out)
ignoreip =
cat /var/log/auth.log

log all the authentication attempts.

restart fail2ban everytime changing the jail files.

systemctl restart fail2ban.service

check if the service is active

systemctl status fail2ban.service

fail2ban-client status

fail2ban-client status sshd

1. Genera

Check which service on which port sudo netstat -tulpn

Ban an IP

sudo fail2ban-client set sshd banip


sudo fail2ban-client set sshd unbanip