OPNsense Firewall Platform

OPNsense Firewall Platform

OPNsense is a powerful, open-source firewall and routing platform based on FreeBSD and forked from pfSense back in 2015 by Deciso B.V. out of the Netherlands.

It delivers enterprise-grade network security features - including stateful packet inspection, Inline IPS via Suricata, traffic shaping, VPN support (WireGuard, OpenVPN, IPsec), and a clean MVC-based web GUI - all without a single licensing fee or vendor lock-in.

The project follows a predictable release cadence with weekly security updates and major releases roughly every six months, and the plugin system lets you bolt on everything from HAProxy to WireGuard to Zenarmor (formerly Sensei) for deep packet inspection.

One of its strongest selling points is the Unbound DNS resolver baked right in, which you can pair with blocklists for network-wide ad and tracker filtering.

Whether you’re running it on a dedicated Protectli Vault appliance or spinning it up in a VM for a lab environment, OPNsense consistently punches well above its weight class compared to commercial alternatives costing thousands per year.

For the full deep-dive, check out the official OPNsense documentation.