OPNsense & pfSense NetFlow Export Configuration Guide

This guide explains how to configure OPNsense and pfSense firewalls to export flow telemetry to your FlowGuard Lite instance.

OPNsense Configuration

1. Log in to your OPNsense Web GUI.
2. Navigate to Interfaces -> Diagnostics -> NetFlow in the sidebar.
3. In the NetFlow Settings panel:
   • Listening Interfaces: Select the interfaces you wish to monitor (typically LAN and WAN).
   • WAN Interfaces: Select your WAN interface (helps differentiate local vs. external traffic).
   • Capture Targets: Enter <FLOWGUARD_LITE_IP>:2055 (where <FLOWGUARD_LITE_IP> is the IP of your FlowGuard Lite host).
   • Version: Select NetFlow v9 or IPFIX.
4. Click Save and Apply.

pfSense Configuration

Since pfSense does not include a native NetFlow exporter out of the box, we recommend installing the lightweight softflowd package.

1. Log in to your pfSense Web GUI.
2. Navigate to System -> Package Manager -> Available Packages.
3. Search for softflowd and click Install.
4. Once installed, navigate to Services -> softflowd.
5. Configure the settings:
   • Interface: Select the interfaces to capture flows on (e.g. LAN).
   • Host: Enter your FlowGuard Lite host IP.
   • Port: 2055
   • NetFlow Version: 9
   • Active Timeout: 60 seconds
   • Inactive Timeout: 15 seconds
6. Click Save.

Validation

Navigate to your FlowGuard Lite Traffic Analysis dashboard. Your firewall’s IP address should appear in the Flow Exporters list, indicating telemetry has begun streaming.