Nmap package

nmap is a powerful network scanner, providing port scanning, OS and service identification, and more.

Usage

Install the package and nmap will be available at Diagnostics > nmap and in the shell (SSH or Console)

The nmap package also installs an OUI database that is used by the pfSense GUI to display manufacturer names on pages that list MAC addresses, such as The ARP Table, and DHCP Leases.

Documentation

Official nmap book