How to Setup a Firewall in Linux

Why Set Up a Firewall?

Setting of a firewall for Linux lies in three primary reasons:

1. Security: A firewall safeguards your device controlling incoming and outgoing network traffic based on predetermined security rules.
2. Access Control: It allows you to specify which services or applications can be access from outside your network. This process will reduce the risk of unauthorized access.
3. Network Segmentation: Firewalls can help segment your network and limit the potential threat of malware or attackers within your network.

Steps to Set Up UFW in Ubuntu

The Uncomplicated Firewall (UFW) is a simple firewall application that is included with Ubuntu and can be installed on other distributions of Linux. By default, UFW is disabled.

In order to see the status of UFW, open Terminal and type in the following command line: sudo ufw status

To enable UFW, enter the following command: sudo ufw enable

By default, ALL incoming traffic is blocked. Here are a few command lines to allow UFW. Proceed to allow for SSH, HTTP and HTTPS.

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To find out the status of the UFW, type in the following command line: sudo ufw status

sudo ufw status verbose – Shows all Rules currently configured for ufw

Additional useful UFW commands

sudo ufw status numbered – Shows rules in numbered order so that you can delete specific rules.

sudo ufw delete 1 – Deletes rule based on number.

sudo ufw disable – Disables ufw

sudo ufw reset – Deletes all rules and disables ufw

The default firewall configuration tool for Ubuntu is ufw. Developed to ease iptables firewall configuration, ufw provides a user-friendly way to create an IPv4 or IPv6 host-based firewall. By default, UFW is disabled. Gufw is a GUI that is available as a frontend.