As the threats to cybersecurity continue to grow, it’s critical to have effective firewall protection in place. Fortunately, there are many powerful and reliable firewall tools available for Linux users that won’t cost a cent. Here are some of the best free Linux firewall tools available today.

1. iptables:

iptable is a popular firewall tool that comes pre-installed on many Linux distros. This firewall tool is a packet filtering firewall that makes it easy to set up rules to allow or block traffic to different ports and IP addresses. It helps in defining custom rules and provides more controlled traffic filtering, making the network more secure.

2. UFW (Uncomplicated Firewall)

UFW offers a user-friendly interface that makes it particularly easy to get started with firewall protection on a Linux system. It uses iptables as the back-end and offers an easy-to-use command-line interface. It provides an excellent graphical user interface which allows users to create rules and commands.

3. Firewalld

Firewalld is another popular Linux firewall tool widely used in Red Hat based Linux distributions such as CentOS and Fedora. Firewalld is a dynamic and flexible firewall management software that offers customization and flexibility. It uses different levels of zones to provide better security, and it’s compatible with many network and firewall protocols.

4. Shorewall

Shorewall is an advanced firewall tool in the Linux ecosystem that offers network address translation (NAT), filtering, and traffic prioritization services. It is a powerful firewall tool and requires an in-depth understanding of firewall rules to use effectively. It offers advanced network configuration tools, which are particularly useful for deploying security policies that need to be applied in a large scale environment.

5. GUFW (Graphical User Interface for UFW)

GUFW is a graphical user interface built on top of UFW that makes it easier to use for those who don’t want to work with the command-line interface. It provides users with a straightforward wizard to set up rules and filter traffic. GUFW is one of the simplest firewall tools to set up a simple firewall on a Linux system.

In conclusion, these are the best free Linux firewall tools available today. Choosing the most appropriate one depends upon your specific needs, level of technical experience and the scope of your network infrastructure. Since cybersecurity threats are always changing, having a strong, reliable firewall in place is essential to keep your Linux system secure.