Fail2Ban Brute Force Protection for SSH Login

SSH brute force attacks are one of the most common security threats faced by Linux servers worldwide. Automated bots constantly scan the internet, attempting thousands of login combinations every day.

Fail2Ban provides a simple yet powerful solution to mitigate these attacks by automatically blocking malicious IP addresses before they can cause serious damage.

What Is Fail2Ban?

Fail2Ban is an open-source intrusion prevention tool that monitors system logs and bans IP addresses showing malicious behavior, such as repeated failed SSH login attempts.

• Real-time log monitoring
• Automatic IP banning
• Customizable security rules
• Reduced attack surface

Why SSH Is a Prime Target

SSH is the default protocol for remote Linux server administration. Its widespread usage and predictable configuration make it attractive to attackers.

Common Risk Factors

• Weak passwords
• Root login enabled
• No rate limiting
• Publicly exposed servers

How Fail2Ban Works

1. Monitors SSH authentication logs
2. Detects repeated failed logins
3. Tracks attempts within a time window
4. Bans offending IP addresses

Installing Fail2Ban

# Debian / Ubuntu
sudo apt install fail2ban -y

# RHEL / Rocky Linux
sudo dnf install fail2ban -y

SSH Jail Configuration Example

[sshd]
enabled  = true
maxretry = 5
findtime = 600
bantime  = 3600

SSH Security Best Practices

• Use SSH key-based authentication
• Disable root login
• Change default SSH port
• Combine Fail2Ban with firewall rules

Fail2Ban in Professional Server Maintenance

Fail2Ban plays a critical role in proactive server maintenance. Continuous monitoring, rule tuning, and log analysis are essential to maintain long-term protection.

At PT Code Hero Indonesia, Fail2Ban is implemented as part of a layered security approach to protect production servers and business-critical infrastructure.