A firewall is a line of defense on your network, primarily used to filter incoming traffic, but also used for outbound rules and other network related security. All major Linux distros come with a software firewall built into them, since it is part of the Linux kernel itself. Any user can configure their system firewall to get started with securing network traffic, but there are many alternatives to the default which will extend or simplify the functionality.
In this tutorial, we have compiled a list of our top picks for the best firewalls available on Linux. The one you pick will largely depend on your goals for securing your network. Of course, corporations or large networks will need a very different firewall solution than a typical end user. You will see a few choices below to help steer you in the right direction to pick a firewall that best suits your needs.
In this tutorial you will learn:
- Best firewall for Linux
| Category | Requirements, Conventions or Software Version Used |
|---|---|
| System | Any Linux distro |
| Software | opnsense, pfsense, ufw / gufw, ipfire, shorewall, firewalld, iptables / nftables |
| Other | Privileged access to your Linux system as root or via the sudo command. |
| Conventions |
# – requires given linux commands to be executed with root privileges either directly as a root user or by use of sudo command$ – requires given linux commands to be executed as a regular non-privileged user |
Best firewall for Linux
Here are some of our top picks for Linux firewalls. Keep in mind that it is not always necessary to download any extra software, since Linux already comes with iptables/nftables baked in – and this is one of our recommendations as you will see below. There are a lot of choices in addition to the ones below, but these are some of our favorites.
OPNsense
OPNsense is a robust firewall that was forked from pfSense – an established, respected firewall – back in 2015. This is a firewall that runs on dedicated hardware, so it will not be a suitable recommendation to typical users. You need to have OPNsense on a separate device that sits between your router and the rest of your network. The idea is that traffic must pass through OPNsense’s filters before being able to access the rest of the devices on your network.
What we like:
- Easier configuration than its predecessor (pfSense)
- Runs on FreeBSD
- Robust options like VPN, load balancing, and traffic shaping
What we don’t like:
- Complicated for a normal user to implement
pfSense
pfSense is another firewall solution that needs dedicated hardware. It has been around for a long time and has a good reputation, so you can find a lot of free support online, as well as paid commercial support in case you need extra help. The interface can be less user friendly than OPNsense, but pfSense is feature rich, with capabilities like VPN, traffic shaping, NAT, VLANs, dynamic DNS, etc.
What we like:
- Good reputation and backed by an established company
- Lots of commercial grade features
- Lots of support and documentation found online
What we don’t like:
- Complicated user interface
ufw / gufw
The uncomplicated firewall (ufw) is a front end for the embedded iptables firewall built into every Linux system. ufw makes the management of firewall rules much easier and less… well, complicated. It is the default firewall on Ubuntu and Manjaro. To make it even simpler, you can install gufw, which is a graphical interface for ufw.
What we like:
- Easy to use for any kind of user
- Installed by default on some user-friendly distros
- Has a graphical interface (optional)
What we don’t like:
- Not suitable for robust firewall filters
IPFire
IPFire runs on dedicated hardware like OPNsense and pfSense, but uses Linux instead of BSD. It features many advanced capabilities but can run on minimum hardware. You can even install it on a Raspberry Pi. This is an easy one to get set up and started with, if you feel like other dedicated hardware solutions are too complicated or just overkill for your network.
What we like:
- Easy to set up
- Can run on minimal hardware
- Various options for deployment
What we don’t like:
- Less online support and documentation
Shorewall
Shorewall can be installed directly to the computer you want it to protect, or on a separate device before your DMZ. It works with zones and simple text files, making it unique from the other choices in our list. System administrators that like simple and minimalistic configuration will find Shorewall to be an attractive solution.
What we like:
- Simple configuarion with text files
- Can run on your PC or a dedicated box
- Works by setting up different zones
What we don’t like:
- No graphical interface
firewalld
firewalld is a front end for nftables on Linux. It is the default firewall for Red Hat and its derivative distributions. It makes configuration a bit easier than working directly with iptables or nftables. Like Shorewall, it mostly configures everything into different “zones.” It is capable of setting up complex rules that would normally be much more complicated to manually implement directly into nftables.
What we like:
- Easier command syntax than iptables / nftables
- Default firewall for all Red Hat distros
- Organizes rules into different zones
What we don’t like:
- No graphical interface
iptables / nftables
Our last recommendation is the very firewall that is already built into every Linux system – iptables or nftables. Many other firewalls on our list are simply a front end for this firewall, meaning that it already suffices as a good firewall solution in the majority of scenarios. Dedicated administrators will not find it too complicated to work directly with iptables, and it is very satisfying to implement a solution without additional software.
What we like:
- No additional software required
- Capable of complex configuration
- Integrated directly into the Linux kernel
What we don’t like:
- Command syntax takes a while to learn
Closing Thoughts
In this tutorial, we learned about the best firewalls to use on Linux. This included a variety of hardware and software solutions, which range from robust, commercial firewalls to simple, end user firewalls. The best solution largely depends on your own preference and what kind of security your network or individual computer needs.
