Open Source Firewall

Introduction :

Open-source firewalls are best known for protecting the network from threats by filtering inbound and outbound traffic and ensuring network security.

Whenever we talk about open-source firewalls, the first thing that strikes our mind is “fully Free.”


However, let me explain it, open-source is the term that is used for the software that is distributed under a license that allows the user access to the source code.

Basically, this type of license simply allows users to analyze and modify the software with complete independence.

Moreover, open source also promotes collaboration between users, which means rapid and varied development of many tools.

What is Open Source Firewall?

Generally, the Open Source Firewall belongs to the community; hence, without any doubt, its development and updates simply depend mainly on the community.

However, the fact is that this also increases confidence in the continuity of the program as well.

Hence, in this post, we will show you the 10 best open-source firewalls to protect your infrastructure.

Just after the arrival of Windows XP Service Pack 1, Windows, by default, offered all its users a very basic and simple firewall.

Generally, with this Windows firewall, we can control the use of our internet connection tools and apps.

Not only that even, but it also protects us from all the possible computer attacks that may arrive through the network.

With the arrival of the Windows 10 Creators Update and the excellent operation of Windows Defender and its firewall, this basic security software has gained great importance and has made more and more users trust it.

But, the fact is that this system couldn’t offer you the whole thing and features that you are finding to secure your infrastructure.

Generally, open-source software offers an economical and adjustable option to deploy basic networking for the infrastructure and home.

Not only that even, but the open-source products also provide us with simple routing and networking functions like DCHP and DNS.

What are the benefits of open source firewall?

These are the main benefits of open source software:

Lower cost: With open source licensing, the code is free.

When you use an open source firewall, you pay for support, security protection, and help managing interoperability.

Table of Contents

What is Open Source Firewall?
What are the benefits of open source firewall?
11 Best Open Source Firewalls 2024
1.Perimeter 81
3.Untangle Firewall
4.OPNsense Firewall
7.IPCop Firewall
Open Source Firewall Features
Other Top 10 Articles to Follow

10 Best Open Source Firewalls 2024

  • Perimeter 81
  • PfSense
  • Untangle Firewall
  • OPNsense Firewall
  • Endian
  • IPFire
  • IPCop Firewall
  • Shorewall
  • SmoothWall
  • Iptables
  • ClearOS

Open Source Firewall Features

Open Source FirewallKey Features
1. Perimeter 811. Secure remote access
2. Cloud agnostic integration
3. Easy to configure & maintain
4. Granular user segmentation
5.Checks for Endpoint Compliance
2. PfSense1. Disable filtering
2. Network Address Translation
3. High Availability
4. Multi-WAN (Wide Area Network)
5.Different WAN load balancing
3. Untangle Firewall1. Spam Blocker Lite
2. Phishing blocker
3. Virus blocker
4. OpenVPN
5.Blocking a country
4. OPNsense Firewall1. Forward Proxy Caching
2. Capital portal
3 Traffic Shaper
4. Virtual Private Network
5.Help with wireless networks
5. Endian1. Email security
2. Multi-WAN
3. Intrusion Prevention
4. Quality of service
5.How to Forward Ports
6. IPFire1. Time server
2. DHCP server
3. Dynamic DNS
4. Catching name server
5.Help for OpenVPN and IPsec
7. IPCop Firewall1. interfaces with typical behavior
2. VLAN available
3. Indirect installation to a flash device
4. Web interface
5.Add-ons and extensions that are flexible
8. Shorewall1. Great interface
2. Multiple interfaces per zone
3. Multiple zones per interface permitted
4. Different rules for proper access
5.Setting up a stateless firewall
9. SmoothWall1. Outbound Filtering
2. Modified time and Accessed time
3. Simple to use and offers a great quality-of-service
4. UPnP support
5.Gateway for the Application Layer
10. Iptables1. Chain-related operation on three-built-in chains
2. Target Disposition
3. Match Operation on the TCP, UDP, and ICMP header fields.
4.IP Filtering for Source and Destination
5.Dealing with Fragmentation
11. ClearOS1. Help with files and prints
2.Managing users and groups
3.List of Servers
4. Intrusion detection and prevention system
5.Market for Applications

All these products can be easily downloaded and deployed on any hardware, on a virtual platform, or in the cloud as well.

However, there are many who also sell them with pre-configured appliances, only if you like their functions or support, and don’t want to build your own machine.

Here in this article, we have mentioned the best open-source firewalls for infrastructure and homes.

However, apart from all these things, we found pfSense and Untangle are some of the best firewalls that could be used in a wide range of environments.

1. Perimeter 81

Perimeter 81

Firewall as a Service (FWaaS) from Perimeter 81 can be set up in minutes and provides safe, off-site access to cloud-based services for businesses.

Additionally, it enables administrators to restrict access to certain network resources based on the identities of individual users or groups.

This means that administrators can simply regulate who in the organization can access which resource.

The FWaaS from Perimeter 81 can be set up in minutes, unlike physical firewalls.

FWaaS’s user segmentation and fine-grained permission-based controls are powerful tools for protecting corporate data and mobile employees.

It works with every platform (Windows, Mac, iOS, Android, and even Linux servers) and any device.

Key Features

  • Integration with threat intelligence services to keep up with the newest security holes and threats.
  • Monitoring and logging all of a user’s actions for security checks and responding to incidents.
  • Connect to Wi-Fi networks safely, making sure that even wireless links are safe.
  • Integration with APIs lets security rules be automated and changed to fit your needs.
  • Endpoint security features may be part of some systems to make sure that devices that connect to the network meet security standards.
What is Good ?What Could Be Better ?
Secure Remote AccessDependency on Internet Connectivit
User-Friendly InterfacePerformance Impact
Scalability and Flexibility
Granular Access Control

Perimeter 81Trial / Demo

2. PfSense


The pfSense open-source firewall is quite similar to Untangle, although it doesn’t have as many bells and whistles as Untangle does, such as web filtering and antivirus.

While this is the case, the package manager provides access to over three dozen more extensions.

With the CD image (.iso), USB image (.usb), or Embedded image (.img) of pfSense, you can install it on your own hardware or virtual machines; it is based on FreeBSD with a modified kernel.

In addition, you can purchase hardware with pfSense already installed on it.

To clarify, a yearly membership to access all of the features and support is available for $99.

In addition, you can get a digital book on pfSense, automatic backups, and a video collection with the most relevant developer tutorials.

Key features

  • High availability installations can keep pfSense running if hardware fails. Load balancing distributes traffic across many WAN links.
  • Multiple WAN (Wide Area Network) connections allow you to connect to the internet multiple ways or share the load.
  • Alternatively, pfSense can function as a DNS server and forwarder for local devices.
  • Stateful firewall rules, NAT, and data blocking are supported.
  • IPv6, the next Internet Protocol, works with pfSense.
What is Good ?What Could Be Better ?
Open-Source and FreeComplexity for Small Deployments
Customizable and ExtensibleHardware Requirements
Comprehensive Security Features
High Performance and Stability

PfSense Trial / Demo

3 . Untangle Firewall

Untangle Firewall

Untangle Open Source Firewall is based on Debian 8.4 and is quite similar to ClearOS.

The core features of the network are supplied, and users can access both free and paid applications to expand its capabilities.

Technically known as NG Firewall, this firewall system may be readily installed on any physical or virtual machine, or you can purchase a device with NG Firewall preconfigured, as we discussed earlier with PfSense.

Key Features

  • Untangle protects against phishing attacks with capabilities that detect and stop them.
  • Untangle’s WAN balancing technology distributes network traffic across many WAN connections to increase speed and reliability.
  • With bandwidth control and QoS, administrators can prioritize traffic and ensure critical applications have the resources they need.
  • Untangle includes many reporting and logging features to help managers monitor network activities, identify trends, and create reports.
  • SSL Inspector scans encrypted messages for risks and filters them to make them safer.
What is Good ?What Could Be Better ?
User-Friendly InterfaceComplexity for Small Deployments
Comprehensive Security FeaturesLimited Advanced Networking Features
Extensive Reporting and Logging
App Store for Additional Functionality

Untangle Firewall Trial / Demo

4. OPNsense Firewall

OPNsense Firewall

OPNsense is a comprehensive Open Source Firewall that is based on FreeBSD and is superior to Deciso’s firewall software.

A Dutch firm designs and manufactures a variety of networking devices and offers paid customer service plans for OPNsense.

It is a fork of PfSense, originally developed by the m0n0wall team, and is based on FreeBSD.

This all began in the first month of 2015.

The m0n0wall development team was transferred to OPNsense by its creator, Manuel Kasper, after the project collapsed in February 2015.

OPNsense supports both i386 and x86-64 architectures and features a web-based user interface.

Key Features

  • Multiple WAN (Wide Area Network) connections allow you to connect to the internet multiple ways or share the load.
  • Dynamic DNS services map dynamic IP addresses to domain names, making them easier to reach from afar.
  • As a DNS server and forwarder, OPNsense may resolve local DNS queries.
  • OPNsense supports IPv6, the future Internet Protocol.
  • As a transparent caching proxy, OPNsense speeds up online browsing by storing frequently used content.
What is Good ?What Could Be Better ?
Open-Source and FreeLimited Commercial Support
Customizable and ExtensibleSystem Updates and Compatibility
Comprehensive Security Features
Active Community and Support

OPNsense Firewall Trial / Demo

5 . Endian


Security solutions based on Linux are available from the Endian Firewall Community (EFW).

There is no need to give or provide assistance, as the software can be obtained without cost. It provides a wide variety of customization options for enhancing existing firewall security.

Users and developers alike will find this program useful for setting up even the most fundamental forms of web and email security with minimal effort.

However, there are more features available, such as robust open-source antivirus protection and VPN capabilities while running EFW.

Furthermore, a few distinct downloads are offered, including standalone distributions that can be set up on individual servers or routers. But you should make sure it does what you need it to do before installing one of these free firewalls.

Key Features

  • As a wireless access point, Endian can connect to Wi-Fi networks.
  • DHCP servers are built into Endian to automatically assign IP numbers to network devices.
  • Endian can resolve DNS queries for local devices.
  • The online interface lets administrators manage firewall rules and policies.
  • Thanks to Endian’s system changes and maintenance tools, the security solution always has the latest updates.
What is Good ?What Could Be Better ?
Interface that is easy to useNot enough community and documentation
Security solution that does everythingChanges in Feature Set
Help with VPNs
Filtering the web and proxy

EndianTrial / Demo

6. IPFire


IPFire is the top open-source firewall since it was built on top of the Netfilter.

It is often modified and created with both modularity and a high level of flexibility in mind.

Simple configuration allows for usage as a VPN gateway, proxy server, or firewall.

Thousands of developers from across the world work together in an online community to update and improve this program.

This free software packs a lot of punch in a small package.

When scanning your network for vulnerabilities, this program also employs an Intrusion Detection System (IDS).

In other words, it will immediately stop the attacker if it detects an attack.

Key features

  • As an internet access point, IPFire can connect wirelessly.
  • IPS features detect and stop network threats, adding protection.
  • IPFire’s “update acceleration” technology speeds up system upgrades.
  • Multiple WAN links can be used for redundancy or load balancing.
  • IPFire add-ons and extensions enable users customize their program.
What is Good ?What Could Be Better ?
Security-Focused FeaturesDependency on Open-Source Components
User-Friendly Web InterfaceLimited Commercial Support
Modular and Extensible
Performance and Stability

IPFire Trial / Demo

7. IPCop Firewall

IPCop Firewall

IPCop, an open-source firewall distribution based on Linux, allows us to keep our network at home and in the office safe and secure.

It lacks a graphical user interface and is only accessible via the command line, which may make it challenging for some users to install and set up the application.

In addition, you might need to have some server and firewall expertise to use the software properly.

This means that sophisticated users have a lightweight option to choose from.

This program is under 60MB in size and was primarily developed for computers with an i486 processor.

Key features

  • It has a DHCP server to assign IP numbers to network devices.
  • IPCop resolves DNS for networked devices.
  • IPCop displays and logs network data for analysis and problem-solving.
  • It is designed for wired networks, but it may operate with Wi-Fi devices with added hardware.
  • This often has system administration and update capabilities to upgrade firewall software with security patches.
What is Good ?What Could Be Better ?
Open-sourceLimited scalability
User-friendly interfaceSoftware updates
Security features
Community support

IPCop Firewall Trial / Demo

8. Shorewall


Shorewall Linux is a free and easy-to-use firewall for servers and routers.

This means its applicability is not restricted to VMs alone.

It is classified as an IPtables setup tool that may transform a server into a hardware firewall appliance.

Shorewall customers can pick a distribution that best suits their requirements.

One public IP address can be hidden on a Linux machine by itself.

There is also a Linux distribution with two network interfaces that can function as a router and firewall for a private network.

The firewall/router and DMZ setup can be customized per user thanks to the router’s three separate interfaces.

The installation options are useful for users who need to conceal many public IP addresses.

Key features

  • Managers can set IPv4 and IPv6 traffic policies with Shorewall.
  • This enables users add add-ons and extensions to their firewall settings for new functionalities.
  • It can be employed in dynamic networks due to its dynamic zones and connections.
  • This allows administrators set conditional rules for specific situations.
  • Shorewall managers can create blacklists and whitelists to restrict or allow traffic based on rules.
What is Good ?What Could Be Better ?
Flexible configurationCommand-line interface
Extensive documentation and resourcesDependency on Netfilter
Support for complex networks
Logging and reporting

ShorewallTrial / Demo

9. SmoothWall


Smoothwall is an open-source firewall program written in the Python programming language and based on the Linux operating system.

Installation and use required minimal familiarity with Linux, and configuration and maintenance were handled using a web-based graphical user interface.

Local area networks, virtual private networks, firewalls (internal and external), Web proxy acceleration, and traffic monitoring and analysis are just a few of the features that this program supports.

In addition, the Web interface is the only place where shutdown and reboot buttons can be found.

Key Features

  • SmoothWall’s logging tools help managers monitor the network and provide reports for analysis and problem-solving.
  • SmoothWall’s user authentication lets administrators restrict access.
  • It allows port forwarding to transfer data between ports.
  • This remote control lets administrators configure and monitor the firewall.
  • SmoothWall’s system updates and maintenance tools keep the firewall software current with security upgrades.
What is Good ?What Could Be Better ?
Security-focusedDependency on SmoothWall hardware
User-friendly web interfaceCommercial support options
Bandwidth management
Add-on modules

SmoothWall Trial / Demo

10. iptables

The greatest open source firewall for Linux applications, Iptables gives a system administrator granular control over network settings and detailed insight into traffic patterns.

It has its own strings and stores and is built on top of the firewall included in the Linux kernel.

There have also been recent shifts toward using unique kernel modules and apps for various protocols.

Iptables is also commonly used as a generic word for kernel-level components.

All four modules, including those that implement the API used for different extensions, share a chunk of the kernel module’s code known by the name x_tables.

Key features

  • Rate-limiting rules can be set in iptables to control data flow.
  • iptables marks packets for specific handling. The IP address TOS field can also be altered.
  • Rules can match IP addresses, groups of IP addresses, or ports. This enables precise traffic control.
  • Iptables’ REJECT and DROP actions let you manage packets that match a rule.
  • iptables supports IPv4 and IPv6, so managers may set rules for both.
What is Good ?What Could Be Better ?
Deep Packet InspectionLack of Graphical Interface
Flexible Rule-Based FirewallLimited Logging and Reporting
Efficient and High Performance
Comprehensive Protocol Support

iptables Trial / Demo

11. ClearOS


More than simply a router firewall, ClearOS is a full-fledged unified threat management (UTM) system with more than 120 customizable features available as applications.

The web-based interface allows for customization of each and every one of them.

In addition, they have ClearVM, a management solution that allows them to install many instances of ClearOS, in addition to other Linux distributions and even Windows, on a single physical server.

Key Features

  • Managers can prioritize network traffic with QoS to ensure critical programs have enough bandwidth.
  • It can control bandwidth usage, allowing administrators to allocate resources to users.
  • This provides email and chat capabilities like collaboration, filtering, and spam prevention.
  • It can centralize storing and writing as a file and print server.
  • A ClearOS DHCP server assigns network device’s IP numbers automatically.
What is Good ?What Could Be Better ?
Easy to UseThird-Party Software Availability
Modular DesignCustomization Constraints
Extensive Feature Set
Community Support

Clear OsTrial / Demo


How does Firewall work?

Now comes the firewall, it’s one of the most significant parts of a network security system.
Because a firewall simply acts as a wall between internal and external networks.
In general, a firewall means activating an application or system which is basically designed to block or allow access to information, both from another system to ours and, of course, from our system to others.

What are the Firewall Features?

Firewalls come with a complete package of security tools and features, like a basic firewall, antivirus, antispam, web filtering, and content filtering with an open-source firewall as well, so what else is needed.


According to Cyber Security News research, these are one of the best Open Source Firewalls available in the open-source world to protect your infrastructure.

We have chosen them because they are cost-effective and user-friendly applications.

So here, we have provided all the information about the top 10 Open Source Firewall lists to protect your infrastructure.

So, try them and see which one is better for you and more helpful. Hence, if you have any other Open Source Firewall application that you have used and think is most suitable, then please let us know in the comment section below.

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Tushar is a Cyber security content editor with a passion for creating captivating and informative content. With years of experience under his belt in Cyber Security, he is covering Cyber Security News, technology and other news.