Best Practices to Prevent SSH Brute-Force Login Attacks in Linux

Here are the top 10 best practices to prevent SSH brute-force login attacks in Linux:

1. Use strong passwords: Use strong passwords that are at least 12 characters long and contain a mix of upper and lowercase letters, numbers, and symbols.

2. Change the default SSH port: Change the default SSH port from 22 to a random high-numbered port. This can make it more difficult for attackers to find your SSH service.

3. Disable root login: Disable root login through SSH and instead use a separate, non-root user account with sudo privileges for administrative tasks.

4. Use SSH keys for authentication: Use SSH keys instead of passwords for authentication. SSH keys are more secure than passwords and cannot be brute-forced.

5. Use fail2ban: Install and configure fail2ban to block IP addresses that have attempted to log in unsuccessfully multiple times.

6. Use SSH daemon rate limiting: Configure your SSH daemon to rate limit incoming connections from a single IP address to prevent brute-force attacks.

7. Use two-factor authentication: Implement two-factor authentication for SSH login to add an extra layer of security.

8. Keep SSH and system software up to date: Regularly update your SSH software and system software to patch security vulnerabilities.

9. Monitor SSH logs: Monitor your SSH logs for suspicious activity and investigate any unusual login attempts.

10. Limit SSH access: Limit SSH access to trusted IP addresses or networks and disable SSH access for users who do not require it.

By following these best practices, you can significantly reduce the risk of SSH brute-force login attacks and improve the security of your Linux system.