Enable Firewall on AnduinOS

Why is the Firewall Disabled by Default in AnduinOS?

If you're new to AnduinOS or Linux in general, you might be surprised to find that its built-in firewall, UFW (Uncomplicated Firewall), is not active right after installation. This may seem like a security oversight, but it's actually a deliberate design choice rooted in a philosophy of "secure by default" and prioritizing user experience. In a fresh AnduinOS system, there are no network services listening for incoming connections. With no open doors, there is nothing for a firewall to protect. The system is inherently secure because it doesn't offer any entry points for potential attackers to target.

The primary reason for keeping the firewall off by default is to prevent a frustrating user experience. Imagine if the firewall were active from the start, blocking all incoming connections. When you later decide to set up a service, like SSH for remote access, a Samba share for local network files, or a web server for development, it would fail to connect without any obvious reason. You would be left troubleshooting a perfectly configured service, only to eventually discover it was being silently blocked by a firewall you didn't even know was active. AnduinOS avoids this "trap" by giving you, the user, the control to enable and configure the firewall precisely when you need it—that is, when you start running services that need to be accessed.

This "clean slate" approach also aligns perfectly with modern computing practices. In cloud environments like AWS or Google Cloud, network security is typically managed at a higher level by "Security Groups," making a host-based firewall redundant and an extra layer of complexity. Similarly, for users who automate deployments with tools like Ansible, starting with a predictable, disabled firewall makes scripting easier and more reliable. UFW remains a powerful and simple tool, ready for you to enable with a single command (sudo ufw enable) as soon as you open your first network port to the world.

How to Enable the Firewall

To enable the firewall on AnduinOS, simply run the following command in your terminal:

sudo ufw enable

But this command is risky because it will block all incoming connections, including SSH. If you are connected via SSH, you will lose your connection and will not be able to reconnect until you disable the firewall or allow SSH connections.

To safely enable the firewall while allowing SSH connections, use the following commands:

sudo ufw allow ssh
sudo ufw enable