PFSense vs. OPNsense: Choosing Your Open Source Firewall Champion

Good morning everyone! Dimitri Bellini here, back with you on Quadrata, my channel dedicated to the fascinating world of open source and IT. You might notice a new backdrop today – still working on the aesthetics, but the content is what matters!

Today, we’re shifting gears slightly from our usual Zabbix discussions to explore another critical area in the open-source landscape: firewall solutions. I’m not just talking about the basic firewall tools within a Linux distro, but dedicated distributions that create powerful network appliances.

Why Dedicated Open Source Firewalls?

Why opt for something like PFSense or OPNsense instead of simpler solutions? Well, whether you’re running a home lab, a small office, or even looking for robust solutions without an enterprise price tag, these distributions offer incredible value. They are designed to be:

• Robust and Reliable: Often running for years without issues, especially on dedicated hardware (like those small, multi-port appliances you often see).
• Feature-Rich: Going beyond basic packet filtering to offer comprehensive network management.
• Versatile: Capable of handling routing, complex NAT scenarios, port forwarding, secure VPN access (site-to-site or remote user), intrusion detection, content filtering, and much more.

Essentially, if you need to manage traffic between your LAN and the internet, securely expose services, connect different locations, or simply have granular control over your network, these tools are invaluable. You can test them easily on a VM using VMware, VirtualBox, or my personal favourite, Proxmox, or deploy them on dedicated, often fanless, hardware appliances.

Meet the Contenders: PFSense and OPNsense

Two names dominate the open-source firewall scene today: PFSense and OPNsense. You’ve likely heard of PFSense; it’s been a stalwart in this space for decades. OPNsense (or OpenSense, as some say) is a newer, but rapidly growing, alternative.

Interestingly, both projects share common ancestry, tracing their roots back to the venerable M0n0wall project. PFSense emerged as an effort to expand M0n0wall’s capabilities. Later, around 2015, as M0n0wall’s development ceased, OPNsense was forked, partly from PFSense code, by developers aiming for a more modern approach and a fully open-source path, perhaps diverging from the direction PFSense was taking with its commercial backing.

PFSense: The Established Powerhouse

PFSense, particularly in its Community Edition (CE), offers a vast array of features:

• Core Networking: Stateful Packet Inspection, robust NAT capabilities, advanced routing.
• VPN Support: Includes OpenVPN, IPsec, and WireGuard (WireGuard often requires installing a package).
• Security Features: Intrusion Detection Systems (IDS/IPS via packages like Suricata or Snort), Captive Portal, Anti-Lockout rules.
• Management: A comprehensive web GUI for configuration, monitoring, and High Availability (HA) setups using CARP.
• Extensibility: A package manager allows adding functionality like PFBlockerNG (IP/DNS blocking), Zabbix agents/proxies, and more.

PFSense is backed by the company NetGate, which offers commercial support and hardware appliances running PFSense Plus. While based on the community version, PFSense Plus is positioned as a separate product with potentially faster updates, additional features (especially related to performance and hardware offloading), and professional support. This is a key distinction: PFSense CE updates might sometimes lag behind the Plus version.

The user interface, while powerful, is often described as more traditional or “retro” compared to OPNsense. It’s built on a FreeBSD base (currently FreeBSD 14 for the latest CE at the time of recording).

OPNsense: The Modern, Fully Open Challenger

OPNsense aims for a similar feature set but with a strong emphasis on usability, security, and a truly open-source model:

• Core Networking: All the essentials like Stateful Packet Inspection, NAT, Routing, VLAN support, GeoIP blocking.
• VPN Support: Also features OpenVPN, IPsec, and WireGuard integrated.
• Security Enhancements: Notably includes built-in Two-Factor Authentication (2FA) support, which is a great plus for securing the firewall itself. It also has strong reporting and traffic visualization tools (Insight).
• Management: Features a modern, clean, and arguably more intuitive web GUI. High Availability is also supported.
• Extensibility: Offers plugins for various services, including Zabbix agents/proxies, Let’s Encrypt certificate management, etc.

The biggest philosophical difference lies in its licensing and development model. OPNsense is fully open source under a BSD license. While there’s a “Business Edition” offering professional support (from Deciso B.V., the company heavily involved), the software itself is identical to the free version. There are no feature differences or separate “plus” tiers. Updates tend to be more frequent, often released on a fixed schedule (e.g., twice a year for major releases, with patches in between).

It’s also based on FreeBSD (currently FreeBSD 13.x at the time of recording, though this changes).

Key Differences Summarized

• Licensing Model: PFSense has CE (free) and Plus (commercial, tied to NetGate hardware or subscription). OPNsense is fully open source, with optional paid support that doesn’t unlock extra features.
• User Interface: OPNsense generally offers a more modern and potentially user-friendly GUI. PFSense has a more traditional, albeit very functional, interface.
• Development & Updates: OPNsense follows a more predictable release schedule and is community-driven (with corporate backing for infrastructure/support). PFSense CE updates can sometimes lag behind the commercial Plus version driven by NetGate.
• Out-of-the-Box Features: OPNsense includes things like 2FA and enhanced reporting built-in. PFSense might require packages for some equivalent functionalities (like WireGuard initially).
• Commercial Backing: PFSense is directly backed and developed by NetGate. OPNsense has backing from Deciso for support/infrastructure but development is more community-focused.

Which One Should You Choose?

Both are excellent, mature, and highly capable solutions. The choice often comes down to your priorities:

• Choose OPNsense if: You prioritize a modern UI, a predictable release cycle, built-in features like 2FA, and a strictly open-source philosophy without tiered versions. It’s often recommended for newcomers due to its interface.
• Choose PFSense (CE or Plus) if: You’re comfortable with its traditional interface, need features potentially exclusive to or better optimized in the Plus version (especially with NetGate hardware), or prefer the ecosystem and support structure provided by NetGate. For business deployments where guaranteed support and optimized hardware/software integration are key, buying a NetGate appliance with PFSense Plus is a very compelling option – you get the hardware, software license, and support in one package, often at a reasonable price point.

Personally, while I love the open-source nature of OPNsense, I also understand the need for companies like NetGate to fund development. If I were deploying for a client needing robust support, the NetGate appliance route with PFSense Plus offers significant peace of mind.

Wrapping Up

Both PFSense and OPNsense empower you to build incredibly powerful network security and management solutions using open-source software. They run on standard hardware or VMs, offer extensive features, and have active communities.

I encourage you to download both and try them out in a virtual environment to see which interface and workflow you prefer. They are fantastic tools for learning and for securing your networks.