The moment you deploy a web server to the cloud, it is targeted by automated scanner botnets. These bots scan your IP address, attempting to break into SSH, Apache, Nginx, or WordPress portals. To secure your server without manual intervention, you need a dynamic defense tool like Fail2ban.
How Fail2ban Operates
Fail2ban is a background daemon that monitors server log files (like /var/log/auth.log or Nginx access logs) looking for suspicious patterns. If an IP address generates multiple authentication failures, Fail2ban updates your system firewall (iptables or UFW) to temporarily block that IP address entirely.
Writing Custom Failures and Jails
Configure a custom jail in /etc/fail2ban/jail.local. Set a bantime of 1 hour, a findtime of 10 minutes, and a maxretry limit of 3 failed attempts. This ensures that any brute-force bot is locked out instantly, reducing server load and protecting your cloud endpoints from security compromises.