How to Set Up a Firewall on Your VPS

What is a Firewall?

A firewall is like a security guard for your server. It controls what can connect to your VPS and what cannot.

A firewall helps keep your VPS safe by blocking bad connections and only allowing the ones you want.

Why Do You Need a Firewall?

Important

Always be careful when setting up a firewall. If you block the wrong ports, you might lose access to your server!

UFW is the easiest firewall to use on Linux servers. It comes pre-installed on Ubuntu and many other Linux systems.

sudo ufw status

If it says "Status: inactive", UFW is installed but not running.

# Block all incoming connections by default
sudo ufw default deny incoming

# Allow all outgoing connections
sudo ufw default allow outgoing

# Allow SSH connections (port 22)
sudo ufw allow ssh

Warning

If you don't allow SSH, you will lose access to your server! Always do this first.

# Allow HTTP (port 80)
sudo ufw allow 80

# Allow HTTPS (port 443)
sudo ufw allow 443

# Example: Allow Minecraft server (port 25565)
sudo ufw allow 25565

# Example: Allow FiveM server (port 30120)
sudo ufw allow 30120

sudo ufw enable

sudo ufw status verbose

If you made a mistake and need to remove a rule:

# Remove a rule by port number
sudo ufw delete allow 80

# Or remove by rule number (check with ufw status numbered)
sudo ufw delete 1

You can test if your firewall is working:

# Check what ports are open
sudo ufw status

# Test if a port is reachable (from another computer)
telnet your-server-ip 80

Good Job!

Your VPS is now much safer with a firewall running. Remember to only open the ports you actually need!