A firewall is a piece of network security software that monitors incoming and outgoing network traffic and permits or denies data packets following a set of security guidelines. In order to prevent unwanted traffic like viruses and hackers, it ensures that a barrier is constructed between the internal network and incoming traffic from outside sources. Organizations employ one of three basic types of firewalls to safeguard their data and hardware against intrusion from malicious parties. 

These include packet filters, firewalls with stateful inspection, and firewalls for proxy servers. In order to prevent attacks, firewalls analyse incoming traffic following pre-established rules and divert traffic from shady or insecure sources. They keep an eye on the activity at ports, a computer’s entry point and where data is transferred to and from external devices. The purpose of a firewall is to protect your device against the threats associated with data-based viruses. Here you can see about the best open source firewall provider:


OPnsense is a hardened BSD-based firewall and routing platform that is open source, easy to use, and simple to construct. Most of the elements in pricey business firewalls are included, along with additional features. Weekly security updates from OPNsense provide augmentations to address emerging risks. The OPNSense firewall has infinite scalability. Best-in-class virtual private networking, intrusion detection, and a robust firewall with support for both IPv6 and IPv4 live view on passed and blocked traffic are promised by this open-source project. 

Hardware failover, state synchronisation, and intrusion detection are all incorporated with multi-WAN functionality. The solution supports two-factor authentication for both the user and third-party services like VPNs. All customers can receive multilingual support, and there is also an elegant user interface for simple access and development.


  • Captive portal
  • Support for plugins
  • DNS server and DNS forwarder
  • DHCP server and relay


You can expand your app’s connectivity to authorised users everywhere through cloud services from Microsoft Azure and Amazon AWS. Connect your staff, partners, clients, and other parties to exchange resources using site-to-cloud, cloud-to-cloud, and virtual private cloud connections. It is the most cutting-edge technology available, Netgate systems with pfSense Plus software offer complete network security solutions for the enterprise, large companies, and SOHO. This makes protecting your network more accessible than ever. It is constructed on the most reliable platforms and has the highest performance, stability, and confidence.

Netgate systems with pfSense Plus software provide comprehensive network security solutions for the enterprise, large companies, and SOHO. It is made with the most currently available cutting-edge technology. Pfsense software is an easy-to-use setup that brings edge firewall, switch, and VPN functionality to homes, businesses, and government offices strengthening and securing networks.


  • GeoIP blocking
  • Anti-spoofing
  • Time-based rules
  • Connection limits


IPFire is a Linux-based firewall that offers business organisations a high level of network protection. It provides robust defence and fends off any online and DDoS assaults. IPFire has a high level of security and is also lightweight and simple to set up. With this software, you can access an intrusive detection system to examine your network traffic and identify potential exploits. IPFire is a Netfilter-based product that thousands of organisations around the world rely on. It has excellent customising options. 

Because IDS is built-in, assaults are recognised and stopped right away. You can also use a guardian to implement automatic prevention. With IPFire, you can get it going in just 30 minutes. IPFire is a modern, open-source firewall built on Linux that is robust, adaptable, and state-of-the-art. Everyone can use it because of its accessibility, good performance in all conditions, and extensibility.


  • Web-based management interface
  • Web proxy
  • Intrusion detection
  • VPN


A Linux-based open-source network operating system called VyOS offers a unified management interface for all operations, much like conventional hardware routers. VyOS provides a free routing platform that is in direct competition with other solutions offered commercially by well-known network companies. VyOS can be utilised as a router and firewall platform for cloud deployments because it runs on common amd64, i586 and ARM computers. You can connect your on-premises networks with cloud sites without the restrictions and costs of vendor-specific VPN solutions because it runs on bare metal as well as popular hypervisors and cloud platforms.

Alternatively, you can build an affordable remote-access VPN for your distant employees. VyOS is an open-source software provider that democratises network access so everyone can create solutions without constraints and exorbitant costs. An edge router is a common application for VyOS since it supports common routing protocols like OSPF and BGP. There are other BGP characteristics, including 32-bit ASNs and standard, big, and extended communities.


  • Routing
  • VPN
  • Network Services


When they combine their firewall and filter products, companies can get a complete set of online security tools from Smoothwall. In addition, the firewall can be accessed independently to provide real-time dynamic threat filtering, gateway anti-malware protection, and bandwidth control. One of the most intriguing tools available is the Smoothwall firewall, which is constantly improved by hundreds of forum users that use Linux and GNU. Even the OS has been made more secure to lessen user’s exposure to firewall flaws. 

The benefits of the Smoothwall filter are also present in the Smoothwall firewall. It is hostile to intrusion detection and prevention, proxy detection and impedance, HTTPS investigation, anti-malware protection, and proxy protection. You can protect your business from all threats by having everything built into one machine.


  • Bandwidth management
  • Link and load balancing
  • Source NAT
  • Intrusion detection and prevention


Endian aims to be the best user-friendly security software in terms of installation, design, and operation. A variety of capabilities is offered by the open-source Endian Firewall Community, a UTM and firewall solution. Although you can access the software for free, you will have to manage it yourself because the developers don’t offer help. With this software, businesses can quickly build email and web security with robust analytics. Not only do you receive a readymade Linux firewall solution when you download EFW, but you also get unified threat management and an open-source antivirus defence program. Even more, assistance is available in the form of complete VPN services.


  • Stateful firewall
  • Antivirus
  • Multi-WAN


Shorewall is a Linux-based open-source firewall program with a wide range of capabilities incorporating the newest technology. It has a wide range of incredible features, including a Net filter system, potential threat monitoring, and many others. Role-based access management and network partitioning are two features that are highly regarded in Shorewall. It supports several systems. 

It allows customers the option to modify the firewall in accordance with their needs. It includes a lot of great features, such as a Net filter system for identifying and monitoring potential threats. Role-based access management and network segmentation are made possible by Shorewall. Numerous systems can be supported, many network interfaces are available, and the firewall can be completely customised to meet your needs.


  • Multiple ISP support
  • Net Filter System
  • Monitoring potential threats
  • Mapping and traffic accounting


ClearOS is an open-source firewall created to transform a PC from its basic state into an accurate internet server equipped with a firewall solution. Three variants of ClearOS, namely ClearOS business, ClearOS community, and ClearOS home, are primarily geared toward corporate companies. The ClearOS community edition of this firewall software is the free version. The business and residential editions must be purchased separately and need a subscription. Also included in ClearOS is a complete network firewall feature, the functionality of which can be improved by integrating extra programmes like DMZ, DHCP, DNS, and many others.


  • Virtual private networking
  • Web proxy
  • Content filtering
  • Antivirus


Software called CSF Firewall was created for people who know the fundamentals of coding. An advanced, all-encompassing technology to safeguard sensitive information from any online threat is ConfigServer Security and Firewall, sometimes known by that name. It offers access to VirtualBox, Ubuntu, and many other programs. It was primarily designed to run on a Linux server. CSF is renowned for utilising the most recent technology, which is constantly being improved by the large developer community with each new version. The major goal, in this case, is to offer a fully secure service.


  • Login Authentication Failures
  • Messenger Service
  • Port Flood Protection
  • Stateful Packet inspection


Untangle NG firewall allows you to manage every part of your network, including Web storage and content purging, remote access, and strategic authorisation, through a simple, natural graphical interface. Applications analyse traffic in parallel and implement complex rules, speeding up execution and throughput. NG Firewall allows IT managers to see everything occurring at the Layer 7 application level of the organisation. It helps with information filtering so you can focus on tools and places that are advantageous for your business. The use of this firewall ensures complete security.


  • Live support
  • Policy manager
  • Branding manager
  • WAN failover

Winding up

As a result the above mentioned are the best open source firewall providers. These are the different types of network security software that monitor incoming and outgoing network traffic before allowing or preventing data based on different safety regulations.