How to Set Up UFW Firewall on Ubuntu 26.04

UFW (Uncomplicated Firewall) is the default firewall management tool on Ubuntu. It wraps iptables with a simplified interface, making it easy to allow or deny traffic by port, service name, or IP range. This guide shows you how to set up and manage UFW on Ubuntu 26.04 LTS.

Tested and valid on:

• Ubuntu 26.04 LTS

Prerequisites

• Ubuntu 26.04 LTS server
• A user with sudo privileges
• SSH access to the server

Step 1 – Check UFW Status

UFW is installed by default. Check its current state:

sudo ufw status verbose

Step 2 – Allow SSH Before Enabling

Always allow SSH first to avoid locking yourself out:

sudo ufw allow OpenSSH

Or specify the port number if SSH runs on a non-default port:

sudo ufw allow 2222/tcp

Step 3 – Enable UFW

Activate the firewall:

sudo ufw enable

Confirm it is active:

sudo ufw status

Step 4 – Allow Common Services

Permit HTTP and HTTPS traffic for a web server:

sudo ufw allow 'Nginx Full'

Or by port numbers:

sudo ufw allow 80/tcp
sudo ufw allow 443/tcp

Step 5 – Allow a Specific IP Address

Grant a trusted IP full access:

sudo ufw allow from 203.0.113.10

Restrict to a specific port:

sudo ufw allow from 203.0.113.10 to any port 5432

Step 6 – Deny a Port

Block a specific port:

sudo ufw deny 8080/tcp

Step 7 – Delete a Rule

List rules with numbers, then delete by number:

sudo ufw status numbered
sudo ufw delete 3

Step 8 – View and Reset

Show verbose rule list:

sudo ufw status verbose

Reset all rules (use with care):

sudo ufw reset

Conclusion

Your Ubuntu 26.04 LTS server is now protected by UFW. As you install new services, remember to open only the ports they need and deny everything else by default.