Basic Firewall Setup with UFW

A firewall controls which network ports can be reached from the internet. On Ubuntu and Debian servers, UFW is the simplest way to configure basic firewall rules.

Install UFW

apt update
apt install ufw -y

Allow SSH first

If your SSH port is 22, run:

ufw allow 22/tcp

If you changed SSH to another port, allow that port instead:

ufw allow <your-ssh-port>/tcp

Allow common services

Only open ports you actually use.

Service	Command
HTTP website	ufw allow 80/tcp
HTTPS website	ufw allow 443/tcp
Minecraft Java	ufw allow 25565/tcp
Minecraft Bedrock	ufw allow 19132/udp
Pterodactyl Wings SFTP	ufw allow 2022/tcp

Enable the firewall

After allowing SSH and any required service ports, enable UFW:

ufw enable

Confirm with y when asked.

Check the current rules:

ufw status verbose

Remove a rule

List rules with numbers:

ufw status numbered

Delete the rule by number:

ufw delete <number>

Recommended defaults

For most servers, use these defaults:

ufw default deny incoming
ufw default allow outgoing

Then explicitly allow the ports you need.

Emergency recovery

If you accidentally block yourself out, use the server console or rescue tools in your hosting panel if available, then disable UFW:

ufw disable

After regaining access, fix the rules and enable it again.