Introduction
Fail2ban is a security tool that monitors server logs for patterns indicating potential attacks, such as brute force attempts. If an attack is detected, Fail2ban automatically bans the IP addresses involved, helping to protect your servers and services.
Installing
To install Fail2ban on Ubuntu 16.04, use the following commands:
sudo apt-get update
sudo apt-get install fail2ban -y
The default configuration file will be located at:
/etc/fail2ban/jail.conf
Configuring (Optional)
To configure Fail2ban, first install a text editor if needed:
sudo apt-get install nano
Then, open the configuration file:
sudo nano /etc/fail2ban/jail.conf
By default, SSH protection is enabled and configured to ban IPs after 6 failed attempts. If you use a non-standard port for SSH or other services, update the configuration to reflect the new port number. For example, if SSH runs on port 2222, you would update the configuration as follows:
[ssh]
enabled = true
port = 2222
filter = sshd
logpath = /var/log/auth.log
maxretry = 6
Other services are listed but not enabled by default. To protect additional services, set enabled = true for each relevant section.
Configuration Legend
- Enabled: Turns monitoring on or off for a service.
- Port: Specifies the port number for the service. Update if using a non-standard port.
- Filter: Defines the rules and patterns Fail2ban uses to detect attacks.
- Logpath: Indicates the log file location. Update if your log file path is different.
Conclusion
With Fail2ban configured, you'll have basic protection for your services against unauthorized access. It's a straightforward tool that enhances server security by managing and mitigating brute force and other attack attempts.
