Security tutorials

Securing your server: firewall, fail2ban, SSH keys, access hardening, automatic updates, VPN, security headers and port auditing.

How to check which ports are open on your server

Find out which services are listening for connections on your server and close what you do not need, for less exposure.

Install ClamAV, an open-source antivirus, and periodically scan your server for infected files.

A few HTTP headers protect your visitors from common attacks like clickjacking and content injection.

Protect your site from bots and simple attacks by limiting the number of requests per second from an IP.

Do not work as root. Create a normal user with sudo for safe administrative operations.

Drop passwords for SSH and use keys, far more secure and impossible to brute-force.

Reduce your server attack surface by disabling SSH root login and moving SSH to a different port.

Run your own private, fast and secure VPN with WireGuard on a VPS, for private browsing and secure access.

Let your server install security patches on its own with unattended-upgrades, so you never stay vulnerable.

fail2ban automatically bans IPs that repeatedly try wrong passwords. Here is how to install and configure it.

Block all unwanted traffic to your server with UFW, a firewall that is simple to configure on Ubuntu.