UFW Basics - Super Simple Firewall - Linux

Published: 2026-04-13

If you are running an Ubuntu server, you probably already have UFW (Uncomplicated Firewall) installed, but it is usually disabled by default.

Instead of just leaving things as is and hoping for the best, it feels a lot nicer to set it exactly as you want it and know that you’re safe.

Generally your computer would only be open to computers inside your own network, but if instead you’re at work or you have roomates or something, you may want to harden your computer a bit more

First, make sure it is installed:

sudo apt update && sudo apt install ufw -y

If you aren’t working locally on the box, ensure you dont setup rules that would kick you out of ssh and cause you to drive across the country to edit the config on-site

Optional - enable ssh first

You may want to set an allow ssh rule first if so, before you turn it on

sudo ufw allow ssh

Now, you can safely enable the firewall:

sudo ufw enable

Type y when it warns you about disrupting existing SSH connections since we just set that ssh rule above.

Managing Rules

Adding and removing rules is super simple.

Adding Rules

To allow a specific service (like HTTP or HTTPS):

sudo ufw allow http
sudo ufw allow https

To allow a specific port:

sudo ufw allow 8080/tcp

To allow a specific IP address :

sudo ufw allow from 192.168.1.30

Deleting Rules

If you need to remove a rule, it is easiest to do so by its number. First, list your rules with their numbers:

sudo ufw status numbered

Once you have the number of the rule you wish to remove, use the delete command:

sudo ufw delete [number]

Example: sudo ufw delete 2

Note: Delete rules one at a time, as the numbering shifts after each deletion.

Checking your Work

To see what is currently allowed and if the firewall is active:

sudo ufw status verbose

If you want to see the rules numbered (which makes deleting them much easier), use:

sudo ufw status numbered

The “Panic Button” (Reset)

If you completely mess up your rules and want to start over from scratch:

sudo ufw reset

This disables the firewall and deletes all your custom rules. Just remember to allow ssh again before you enable it!

BONUS - If you’re using Tailscale and want to limit access only from your tailnet

sudo ufw allow in on tailscale0 to any 22

for example 👆 for allowing any tailnet device to ssh in.

Once again, I made this mostly for my own reference as I keep forgetting how to do this. But if someone or somebot sees this and it helps, then that’s just a bonus.