Firewalls are made to protect the network from any threat by filtering both the in and outbound traffic and ensuring network security. The first thing when we talk about the 9 best open-source firewalls for Windows and Linux is that they are free, well let us explain such a term for software that is distributed under a license. These are compatible with various Linux distributions along with Windows 10/11.
With the help of this license, users can analyze and modify software with full independence. It is also used to promote user collaboration, which means quick and varied development of different tools.
As it belongs to the community, its development and updates are its responsibility. This is used to increase program continuity. If you talking about firewalls then keep in mind that this by far is the most important part of a network security system.
As it acts as a wall between the internal and external networks. To put the long story short this means activating any app or system which is designed primarily to block or allow access to information that is coming from one system to ours and vice versa.
About Open Source Firewalls – What are they?
Microsoft Windows offers users, a basic yet simple firewall after the arrival of Windows XP Service Pack 3. With this we can have control over the use of internet connection tools and applications, moreover, it is also used to provide protection from all the PC attacks that might make their way via the network.
As the new Microsoft version 11 Creators Update and the great operation of Windows Defender as its Firewall, it has become an integral part of the user’s needs. The only drawback is that the system cannot offer users the complete thing along with features required to secure the infrastructure.
Open-source software offers users quite an easy-on-the-pocket and adjustable option to deploy basic networking for home and infrastructure. They also provide users simple routing and networking functions such as DNS and DCHP. The best thing is that they are packed with security tools and features such as anti-spam, web filtering, and content filtering.
We can download these products and deploy them on any hardware on the virtual program or in the cloud. Today, many users also sell them along with pre-configured appliances, only if you have a like for either their support or functions, and you do not want to get in the hassle of building your very own machine.
We have mentioned to you by far the best open-source firewalls for both home, small businesses and enterprise infrastructure so what is the wait?
Let’s begin…
9 Best Open Source Firewalls For Windows and Linux (Free Picks)
PfSense Community Edition – Everything you will ever need
This one comes with a lot of similarities with Untangle but lacks in many features such as web filtering and anti-virus. The best part is that it carries more than 3 dozen external add-ons for easy installation via the package manager.
It is based on FreeBSD with a custom Kernel which can be installed on the hardware or virtual machines with CD image (.iso), USB, and Embedded image (.img) of these. We also have the option to buy pre-loaded PfSense on the hardware too.
It offers users a membership that costs $99 per year. For support and services, we get resources such as a library of videos from developers which are of extreme importance, its digital book as well as an automatic backup.
Perimeter 81 – A cloud-based solution
FWaaS, which is Perimeter 81’s Firewall as a Service, is much easier to configure and enables users to secure remote access to cloud-based resources that are way out of the corporate office. If you are an admin, it allows you to segment access to particular network resources based on user or group identities. To put the story short, it means that administrators can have control that who in the organization can have access to which resource easily.
The best thing about this is that we can deploy it in the cloud. The granular permission-based policies and user segmentation included are quite effective in securing both remoted workers and company resources. It has compatibility with Windows, iOS, Android, Mac and Linux servers.
RECOMMENDED: Orbot VPN Client For Windows 10 & 11 (Free).
OPNsense – A fully-fledged secure platform
This is an open-source; FreeBSD-based firewall that is able to overpower software that is deployed by Deciso. A company based in the Netherlands was issued to make different hardware and sell support packages for this.
This is a branch of PfSense that got turned into forked from the mOnOwall, which those who do not know created FreeBSD. It started back in 2015, when mOnOwall got shattered in 2015, the inventor, Manuel Kasper, assigned its developer community to it which for now has web-based UI and is being on i386 and x86-64 platforms.
Untangle Firewall – NGFW
This is yet another option that has a lot of similarities with ClearOS and is based on Debian 8.4. It carries basic network functionalities with comes with both free and paid apps to add in additional functions which are managed via web-based UI.
To put it in technical terms it is named NG Firewall and can be installed easily on any hardware or virtual machine or we can also purchase a device with NGFW pre-installed just like in the case of PfSense explained above.
IPFire – Massive support community
This one is developed on top of Netfilter and it seems to be one of the best open-source firewalls. By keeping in mind modularity and flexibility it has been designed and can be used as a proxy server, or even VPN gateway easily. You can then use an open-source VPN client on Windows to connect to it over the public internet.
It is being handled by an online community that has many developers. The best thing is that it would not be too heavy on the system and is quite powerful as well. It uses IDS which stands for Intrusion Detection System to analyze traffic and find potential exploits. To put it short, this is used to detect any attack and directly block the attacker.
Iptables – The real deal
This one is quite a popular utility present on the list and it seemed to be one of the best open-source Firewalls for Linux operating systems out there which are used to provide system administrators both the control and option to configure and analyze network stats. It has been developed with Linux Kernel plus comes with its own strings and stores too.
Recently, different Kernal modules and apps have been used for various protocols. This term also refers to Kernel-level elements. x_tables is the name that the Kernel module carries and shares it code portion which is being used by all four modules which implement API used for various extensions.
SmoothWall – Law Enforcement Grade Protection
It is used to provide support to LAN, DMZ, Internal or external networks, web proxy for acceleration, traffic statistics and much more.
With only a web interface, this can be shut down or rebooted.
Endian Community Edition – A secure BYOD network
EFW which is the Endian Firewall Community provides Linux-based security solutions for all its users out there. The best thing about this one is that it comes both free and developers don’t require any support or offer. It provides users with many options to add extra protection.
Use this to set up basic web and email security according to need. Moreover, it has many more features for Windows. When a user uses EFW he gets powerful open-source anti-virus protection along with VPN support for Windows 11.
It carries some different downloads as well such as standalone distributions which are installed on individual servers or routers. Make sure it meets all your needs and then decide to install it.
ClearOS – A secure foundation for an OS
This is the last option on the list which is not only a router protector but is a unified threat management (UTM) solution that offers users more than 120 functions through add-ons which are called applications. Now, through its web-based interface, all of these are configurable.
Moreover, there is also a ClearVM, a management solution used to deploy different ClearOS virtual machines, other Linux distributions, and the Windows Operating system on the physical server.
Linux distro comparisons for your next server:
Conclusion: Best Open Source Firewall
The benefits of having open-source security measures outweigh the drawbacks. There are more professionals analyzing and upgrading the codebase and fixing bugs and critical vulnerabilities. Our list of 9 open-source Firewalls that are free for personal, educational and testing uses. Many are also modified and used at an enterprise level by businesses as they are so good.
