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 Group Test 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 |
| iptables | Configure the Linux 2.4.x and later packet filtering ruleset |
| Shorewall | High-level tool for configuring Netfilter |
| ufw | Uncomplicated Firewall. This is software for managing a netfilter firewall |
| gufw | Easy, intuitive, way to manage your Linux firewall |
| Portmaster | Application firewall that does the heavy lifting |
| Vuurmuur | Uncomplicated Firewall, manage a netfilter firewall |
| awall | Firewall configuration tool, providing various benefits over plain iptables |
| bgpipe | BGP reverse proxy and firewall |
| Foomuuri | Multizone bidirectional nftables firewall |
This article has been revamped in line with our recent announcement.
 Read our complete collection of recommended free and open source software. Our curated compilation covers all categories of software. The software collection forms part of our series of informative articles for Linux enthusiasts. There are hundreds of in-depth reviews, open source alternatives to proprietary software from large corporations like Google, Microsoft, Apple, Adobe, IBM, Cisco, Oracle, and Autodesk. There are also fun things to try, hardware, free programming books and tutorials, and much more. |
OpenSnitch, what an unfortunate name.
Never judge a book by its cover.