pfSense vs OPNsense – Which Firewall is Better? (Pros and Cons)

pfSense vs OPNsense – Which Firewall is Better? (Pros and Cons). All in all, firewalls are essential for safeguarding your computer, server and network against malicious attacks. Firewalls are designed computer systems against cyber attacks and unauthorized access, monitor network traffic, and detecting malicious activity. A firewall is an essential cyber security tool that every system should have. The best firewalls are those that are well configured, regularly updated, and highly secure. With the increasing sophistication of cyber threats, selecting the right firewall for your system is essential for ensuring maximum security.

OPNsense and pfSense are among the most popular firewalls. Mainly because of their robust features. They both function as firewalls and also enable you to create VPNs, VLANs, and more. Basically, pfSense was launched in 2006 while OPNsense is a fork of pfSense launched in 2015. Both programs protect and manage your network while offering additional features such as web filters and site tosite support.

This article provides a comparison of pfSense and OPNsense and an overview of their best features. By understanding how each firewall works, you make an informed decision on which firewall to choose to secure your business systems. 

Shall we start with pfSense vs OPNsense – Which Firewall is Better? (Pros and Cons).

What is pfSense?

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pfSense is a free, open source variation of the FreeBSD OS that functions as a firewall and router. Moreover, it offers a powerful, versatile solution for securing networks. Based on the reliable FreeBSD operating system and utilizing the robust PF firewall engine, pfSense provides users with an unbeatable customization options. Also, it comes with many advanced features like support for VPN protocols, intrusion detection systems and content filtering capabilities. 

Additionally, pfSense comes with an easily navigable interface for easy management. You do not require FreeBSD knowledge to use and deploy this firewall. In addition to being a robust and flexible firewall and router platform, pfSense has various features and a unique package system. This software package enables the operating system to expand without adding security holes that bloat the distribution.

How Does pfSense Work?

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pfSense is a stateful firewall. This means it remembers information about connections going through the Firewall to automatically enable reply traffic. All data in pfSense is stored in the State Table. The connection data in the state table includes the destination source, ports, protocols, and more that help to identify individual connections uniquely.

With this mechanism, the user restricts traffic to the interface where it enters the Firewall. Once a connection matches a pass rule, the Firewall generates an entry in the state table. Reply to traffic connections is allowed back via the Firewall by matching it against the state table. This also includes any related traffic using different protocols, like ICMP messages that might be given in response to a UDP, TCP, or other connection.

Features of pfSense

Stateful Firewall

Stateful firewall that tracks individual sessions of network connections flowing through it. You configure pfSense to block traffic depending on policy matches. Alternatively, users inspect IT without blocking traffic by including pass rules for traffic on every interface.

Geo Blocking

Geo blocking feature that blocks internet traffic from entire countries to stop cyber criminals from attacking your organization. GeoIP blocks network connections based on information collected from IP addresses which you then use to filter and stop incoming and outgoing connections to and from your enterprise. By default, pfSense blocks all unwanted inbound traffic to the WAN interface.

Time Based Rules

Moreover it enables you to set time based rules such that it activates during user specified days or periods. Time based rules work the same as other rules, except they are absent the in the rule set outside their scheduled times.

Connection Limits

The connection limit policy permits or denies traffic depending on a matching tuple: destination address, source address, and connection count. This allows for easy detection of irregular connection requests.

Policy Based Routing

With policy based routing, it routes and forwards data packets according to specified policies or filters. This feature uses parameters such as source or destination port, source and destination IP address, packet size, access list, and more to route packets on user defined routes. Also, it has a static routing mechanism whereby a router employs a manually configured routing entry instead of information from dynamic routing traffic.


Intrusion Detection System (IDS) analyzes network traffic for signatures that are similar to known cyber attacks. The IDS also analyzes packets, but stops the delivery of the packet, helping to stop the attack.

Pros of pfSense

  • Simple configuration rules suitable for inexperienced users.
  • XML based backup and restore.
  • Consumes minimal CPU and RAM.
  • Configure it to load balance internet connections.
  • It logs all traffic and filters out bad traffic.

Cons of pfSense

  • Lacks a unified management console for multiple devices.
  • No scripting or automation capabilities due to lack of a CLI.

Next in this article blog pfSense vs OPNsense – Which Firewall is Better? we compare the second tool OPNsense.

What is OPNsense?

OPNsense is a fork of pfSense and has most of the features available in industrial firewalls. This FreeBSD open source firewalling system comes with an intuitive and easy to use interface. OPNsense mainly focuses on code quality and security while offering advanced features such as traffic shaping, intrusion detection, and forward caching proxy. It also provides options that enable organizations to use OpenSSL or LibreSSL.

OPNsense’s reliable update mechanism allows it to handle new and emerging threats while providing a secure and stable user environment.

Features of OPNSense

Besides, OPNsense is a powerful firewall and routing platform. With the set of high end features such as intrusion detection, traffic shaping, and many more. Here are some of the top features of OPNsense:

Caching Proxy

Provides a full feature caching proxy that includes category web filtering, running in transparent mode, and extensive Access Control Lists. You combine the proxy with the traffic shaper to improve user experience. Additionally, the ICAP interface allows integration with most Anti Virus solutions.

Stateful Firewall

A stateful firewall monitors the state of network connections moving across it. OPNSense groups firewall rules by category, which is especially useful for more demanding network setups.

High Availability/ Hardware Fail-over (CARP)

Also, the tool has the Common Address Redundancy Protocol (CARP) for hardware fail over. You configure two or more firewalls to act as a fail over group. If the primary goes offline entirely or one interface fails on the primary, the secondary becomes active. With this feature, OPNSense generates a redundant firewall with a smooth and automatic fail over. At the same time, the system switches to the backup network connection that remains active with minimal disruption for the users.

VPN – Ipsec and OpenVPN GUIH3

After all, OPNSense provides a variety of VPN technologies like IPSec, modern SSL VPNs, and older legacy options such as PPTP and L2TP. Road warrior and Site to Site setups are possible, and the integrated OpenVPN client exporter allows you to configure the client quickly.

Traffic Shaper

Offers a flexible traffic shaping approach organized around queues, pipes, and corresponding rules. The pipes define the permitted bandwidth, you use the queues to set a weight in the pipe, and finally, you use the rules to apply the shaping to a specific package flow. Users handle the shaping rules independently from other settings and firewall rules.

Intuitive Interface

Provides a dashboard where you check the status of your firewall easily. Besides, the user interface comes with built in help, multi language support, and quick navigation, which helps to improve user experience.

Pros of OPNsense

  • Easy to configure and use.
  • Full 2FA support using Google Authenticator.
  • Utilizes CARP for hardware failover and to maintains high availability.
  • Scales easily when running on the hardware.
  • Backs up configuration changes automatically so you view history of changes.

Cons of OPNsense

  • You have to configure everything with the graphic user interface, unlike other firewalls that you can configure with code.
  • Lacks a peer blocking feature.

It is time to compare pfSense vs OPNsense – Which Firewall is Better?

Main Differences Between pfSense and OPNsense

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Both pfSense and OPNsense have great similarities. Both are stateful firewalls and allow you to set up things like VLANs and VPNs. However, they have a major differences that set them apart. Here are some of the top differences between pfSense and OPNsense:


Netgate distributes pfSense under the Apache 2 license, which restricts the freedom of users to change and modify the system for various reasons. On the other hand, OPNsense operates under an open source initiative approved license, which allows users to modify or even re develop it for different uses.

User Interface

While pfSense has a clean user interface, OPNsense has a more logical and easier to use interface, meaning everything is where you’d expect it to be. In OPNsense, you navigate via the settings by using the dashboard on the left side of the screen. PfSense has a dropdown menu bar at the top.

Whereas OPNsense feels logical, pfSense feels bulky. This is not necessarily bad, as most of those additional items are useful in customization. However, it might take some users longer to find what they are looking for than it should. This is because pfSense has a lot of menu options.

Operating System

Both pfSense and OPNsense are variations of FreeBSD. pfSense uses a more modern version and puts more effort into making the system easier to use. With OPNsense, you to automatically load drivers into the kernel of the system startup. Also, you need to tinker with configuration files to start it. This approach is quite cumbersome, and including a network card may result in a system reboot which is not the case for pfSense.

Intrusion Detection

pfSense’s intrusion detection system (IDS) analyzes network traffic to filter out malicious attacks. basically, it acts as a IDS on itself, although it utilizes Snort and Suricata add ons for intrusion prevention. On the other hand, OPNsense IDS is based on Suricata and utilizes Netmap for resource utilization. This results in a deep packet inspection system that can mitigate threats efficiently.

Reporting and Monitoring

pfSense and OPNsense have different reporting and monitoring options. pfSense takes a rather traditional approach to monitoring and reporting. It has a dashboard with configurable widgets that provide an excellent view of system information and graphical data. Also, it supports various local monitoring graphs to enable you view VPN usage, traffic, WAN interface quality, etc.

On the other hand, OPNsense offers numerous reporting and monitoring options. It utilizes RDD graphs to display system health information. Also, you use the network flow exporter to view usage data and active ports. With the integrated Netflow Analyzer, you view insights without installing additional add ons or plugins.

Backup & Restore

pfSense has a backup & restore feature accessible via the GUI Diagnostics menu. To backup your files, all you need is to select an XML for the backup. The computer with then store the XML file that you use later for restoration.

In OPNsense, you easily download a backup file within the GUI and encrypt it for maximum security. OPNsense supports cloud backup so you easily store many files for long. To make this possible, it has integrated Google Drive on the GUI.

Thank you for reading pfSense vs OPNsense – Which Firewall is Better? (Pros and Cons). We will conclude this article blog.

pfSense vs OPNsense – Which Firewall is Better? (Pros and Cons) Conclusion

Apart from minor differences, both platforms primarily provide almost similar performance, functionality, and hardware compatibility. OPN sense is slightly secure because of HardenedBSD and frequent releases. PfSense is somewhat more stable due to ZFS support and fewer releases. Both are great tools, and the ideal choice should be dependent on your individual business needs.

Avatar for Dennis Muvaa
Dennis Muvaa

Dennis is an expert content writer and SEO strategist in cloud technologies such as AWS, Azure, and GCP. He's also experienced in cybersecurity, big data, and AI.

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