FortiNAC learns about endpoints connecting to the network using multiple methods, and one of the key methods in wireless network integrations is through RADIUS communication.
When a device attempts to connect, RADIUS requests provide MAC address information to FortiNAC.
FortiNAC can also use SNMP traps (link traps or MAC notification traps) and traffic monitoring, but RADIUS is the main standard method for wireless MAC address acquisition.

FortiGate for application control and intrusion prevention system (IPS): In the control area zones, FortiGate can provide critical security measures such as application control and intrusion prevention. This helps detect and prevent unauthorized activities and threats targeting the OT network.
FortiNAC for network access control: FortiNAC can be used to enforce network access policies, ensuring that only authorized devices and users can access specific zones within the control area, thereby reducing the risk of unauthorized access or breaches.
FortiSIEM for security incident and event management: FortiSIEM provides centralized monitoring and analysis of security incidents and events across the OT environment. It helps to identify potential threats, improve visibility, and ensure quick responses to security incidents.

FortiNAC stores which profiling rule originally matched a device. When it later re-evaluates that device, it compares against the same saved rule to confirm or change classification.