How can I protect against brute-force attacks which target my VPS?

Brute-force attacks are a common type of cyberattack, where malicious bots scan the internet and try to gain access to servers via services like SSH, RDP, or FTP by repeatedly guessing random or commonly used passwords.

If you're managing a VPS, it's important to know that these attacks are often carried out by large botnets using distributed IPs, making them harder to detect and block effectively.

Practical steps to protect your VPS

• Evaluate whether services like SSH or RDP really need public access: If not, restrict access to a private network or specific IPs only.
• Change default ports:
  • For SSH, change the default port 22 to something less common (e.g. 2202).
  • For RDP (Windows), change the default port 3389.
• Use SSH keys instead of passwords: Key-based authentication is much more secure and renders brute-force attempts ineffective.
• Install brute-force protection software: On Linux systems, tools like Fail2Ban are very effective — they detect failed login attempts and automatically block suspicious IPs.
• Apply firewall rules: If some regions or countries don’t need access to your server, you can block entire IP ranges via your firewall.
• Move servers to a private network: If certain services don’t need to be exposed to the internet, place them in a private network and remove public access. You can also use a VPN and pfSense for controlled access to specific ports.

Note: Many brute-force attacks originate from infected systems whose owners are unaware that their machines are being used this way. So be cautious when blocking IPs or ranges — overly broad blocks may affect legitimate users.

For complete protection, combine these measures with monitoring tools and regular audits of access attempts on your VPS.