Security is paramount. Security involves defense in depth. Approaching security one step at a time, with consistency and rigour, you can mitigate threats, and keep intruders at bay.
Intruders use a variety of different techniques in an attempt to compromise a system. For example, systems can be attacked by denial of service, cracking, intrusion, snooping (intercepting the data of another user), or viruses/worms/Trojan horses. To have a secure box, a system therefore needs a variety of defenses.
One important step to protect a system is using a firewall. Essentially, this is a network security system, acting like a security guard between internal and external networks. The firewall controls incoming and outgoing network traffic using security rules. The rules specify which connections you want to allow and the ports and zones through which the connection can be established.
This roundup recommends a good selection of firewall tools. Only free and open source tools are eligible for inclusion.
Let’s explore the 12 firewall tools at hand. For each title we have compiled its own portal page, a full description with an in-depth analysis of its features, together with links to relevant resources.
| Firewalls | |
|---|---|
| OpenSnitch | Interactive application firewall |
| nftables | Provides a new in-kernel packet classification framework |
| Firewalld | Dynamically managed firewall with support for network/firewall zones |
| Portmaster | Application firewall that does the heavy lifting |
| iptables | Configure the Linux 2.4.x and later packet filtering ruleset |
| ufw | Uncomplicated Firewall. This is software for managing a netfilter firewall |
| Shorewall | High-level tool for configuring Netfilter |
| gufw | Easy, intuitive, way to manage your Linux firewall |
| Vuurmuur | Uncomplicated Firewall, manage a netfilter firewall |
| awall | Firewall configuration tool, providing various benefits over plain iptables |
| Foomuuri | Multizone bidirectional nftables firewall |
| bgpipe | BGP reverse proxy and firewall |
This article has been updated to reflect the changes outlined in our recent announcement.
 Explore our comprehensive directory of recommended free and open source software. Our carefully curated collection spans every major software category.This directory is part of our ongoing series of informative articles for Linux enthusiasts. It features hundreds of detailed reviews, along with open source alternatives to proprietary solutions from major corporations such as Google, Microsoft, Apple, Adobe, IBM, Cisco, Oracle, and Autodesk. You’ll also find interesting projects to try, hardware coverage, free programming books and tutorials, and much more. Know a useful open source Linux program that we haven’t covered yet? Let us know by completing this form. |
OpenSnitch, what an unfortunate name.
Never judge a book by its cover.