UFW Essentials

UFW is a user friendly method of managing incoming and outgoing firewall rules on a Linux system.

Allows both tcp and udp for specified port

ufw allow 53

Allows specified port over specified protocol

ufw allow 53/udp

Utilize in or out to apply rules to incoming or outgoing traffic

ufw allow in http
ufw reject out smtp

Deny traffic to specific interface

ufw deny in on eth0 to 192.168.0.1 port 25 proto tcp

Allow multiple ports for specific use case such as a web app

ufw allow proto tcp from any to any port 80,443,8080:8090 comment 'web application'

Allow traffic in from a specific IP

ufw allow from 192.168.0.1

Allow traffic from specific IP to specific port

ufw allow from 192.168.0.1 proto tcp to any port 443

Alternatively allow an entire subnet by replacing the ip 192.168.0.1 with 192.168.0.0/24

Create a file with the application name in /etc/ufw/applications.d

[SomeApp]
Title=SomeApp
Description=SomeApp is a demo app.
ports=8080,8081/tcp|12/udp

Register the app in UFW for use with UFW rules

ufw app update someapp

Use the app in a policy

ufw allow someapp

ufw allow from 192.168.0.1 to any app 'someapp'