Firewalls are one of the most important parts of a network security system. In simplest terms, a firewall is a digital wall placed between the internal and external networks. They are very important for protecting a network from a cyber threat. Firewalls both filters inbound and outbound traffic to provide comprehensive protection and decides which requests can pass and which ones get blocked.
Nowadays, most organizations are using open-source firewall solutions, and there is an important reason behind that. The term “open-source” is mostly related to free software, but it is not the main priority for many organizations to prefer open-source solutions. Source code of software distributed under an open-source license can be accessed and changed by the user.
It allows organizations to understand how the software works and more importantly change them to meet their needs, and basically turn them into purpose-built solutions. Thus, open-source firewalls offer features most organizations need, and are free and adjustable. Also, open-source projects are developed and maintained by their communities, which almost eliminates the risk of reaching unexpected end-of-life.
Another significant benefit of open-source firewalls is that they can be deployed on any hardware, on virtual platforms, and cloud. Some of them are also coming with pre-configured appliances to make it even easier for organizations.
So let’s take a close look at some of the industry’s most popular open-source firewalls.
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pfSense
pfSense is an open-source and free version of FreeBSD, designed to be used as a firewall and a router. With its unified threat management, load balancing, and multi-WAN features, it is one of the most popular free open-source firewalls on the market.
Another reason for its popularity is its user-friendly web interface which makes administration much easier for users, especially for new beginners and those who have limited technical knowledge. Its UI can even handle software updates. pfSense can also support most hardware, including old ones and embedded systems. pfSense is updated and patched frequently to protect its users against known threats. pfSense is mostly configured as a DHCP server, DNS server, WiFi access point, and VPN server.
OPNsense
OPNsense, developed by a Netherlands-based company Deciso, is a FreeBSD-based firewall and routing software. The project was started as a fork of pfSense and m0n0wall in 2014 and was initially released in the January of 2015. It offers most of the features included in commercial firewalls with the benefits of open-source.
OPNsense is also frequently updated to protect its users against the latest emerging threats. The release is based upon FreeBSD for long-term support along with the MVC framework based on Phalcon. It is also powered by Hardened BSD, a FreeBSD fork that focuses on security. Some of the most notable features of OPNsense are forward caching proxy, traffic shaping, intrusion detection, and easy OpenVPN client setup. It supports almost as much hardware as pfSense does.
IPFire
IPFire is a hardened and open-source Linux distro that focuses on security. It is capable of performing as a router and a firewall. It comes with a standalone firewall system and a web-based management console, which makes it easier for users to configure the firewall.
The IPFire project started as a fork of IPCop and allows users to add server services by installing add-ons. IPFire uses a Stateful Packet Inspection, built on top of the Linux packet filtering framework, Netfilter. Its Intrusion Prevention System analyzes network traffic to detect exploits, leaking data, and any other suspicious activity. It is also one of the easiest solutions to set up to be used as a firewall, proxy server, or VPN gateway. IPFire is known for being a lightweight solution and it is maintained by an online community, including thousands of developers.
ClearOS
ClearOS, developed by ClearFoundation, is a Linux distribution. The CentOS-based router OS is a unified threat management solution. With its add-ons referred to as applications, it offers over 120 functions, configurable with its web-based interface.
There are three versions of ClearOS, depending on the users’ needs: ClearOS Enterprise, ClearOS Home, and ClearOS Core. ClearOS’ free and fee-based applications and services are organized into 6 categories: Cloud, Gateway, Server, Networking, System, and Reports. Most popular applications include network and gateway applications such as firewalls, and Content filters along with server applications such as mail, media, and file/print.
Endian Firewall Community
Endian Firewall Community, developed by Endian, is a Linux security distribution. It performs as a gateway, router, and firewall that can act as a proxy for web, email, FTP, SIP, and DNS. The Unified Threat Management solution provides basic email and web security services.
The solution uses its Advanced Content Security backed by CYREN and Bitdefender Anti-malware Engine. Endian Firewall Community mainly focuses on usability and it is one of the most simple to install, use, and maintain solutions. Endian Firewall Community offers additional features, including commercial support, and access to the Endian Network.