🧱How to Set Up a Firewall (UFW)

Introduction

UFW ("uncomplicated firewall") is the simplest way to lock down a Linux VPS. It's a friendly wrapper around iptables.

Install UFW

apt install ufw -y

Most Ubuntu VPS images come with UFW preinstalled.

Set Up the Default Rules

1. 1Allow SSH first, don't lock yourself out:

   ufw allow OpenSSH

1. 1Deny everything else inbound:

   ufw default deny incoming
   ufw default allow outgoing

1. 1Enable:

   ufw enable

1. 1Type y to confirm
2. 2Check status:

   ufw status verbose

Only SSH gets through. Everything else is blocked.

Add Service-Specific Rules

• HTTP & HTTPS: ufw allow 'Nginx Full'
• Minecraft: ufw allow 25565
• Custom port: ufw allow 8080/tcp
• Range: ufw allow 5000:6000/tcp

Remove a Rule

1. 1List numbered rules: ufw status numbered
2. 2Delete by number: ufw delete 3

Tip: Run ufw status after every change. Make it a habit.

Warning: Always allow SSH before enabling UFW. If you forget and you're on a remote VPS, you'll lock yourself out and need console access.

Disable UFW

ufw disable

This stops the firewall but keeps your rules saved for next time.

Need More Help?

Locked yourself out? Use the VNC console in the panel, that bypasses SSH.