In the AAA model, Authentication is the act of proving identity and verifying that the account is valid and active. Just as the club system checks the database to confirm the cardholder is a legitimate member before opening the door, ClearPass checks an identity store (like AD or the Guest DB) to confirm a user's credentials are correct and their account hasn't expired before allowing them onto the network.

This scenario describes a MAC Spoofing attack. Since a MAC address is easily faked, ClearPass Profiler uses
"Fingerprinting." While the attacker's laptop may have the camera's MAC, its DHCP Options (the order and type of parameters requested) and its HTTP User-Agent string will identify it as a "Windows" or "Linux" device rather than a "Linux/Embedded Camera." ClearPass detects this profile conflict and can trigger a CoA (Change of Authorization) to bounce the port or move it to a restricted VLAN.

OCSP (Online Certificate Status Protocol) is designed to provide real-time revocation status. If an OCSP responder returns a status of 'unknown' , it means the responder has no record of the certificate. From a security standpoint, ClearPass treats any response other than 'Good' as a failure. To prevent potential unauthorized access via certificates that the PKI cannot verify, ClearPass will reject the authentication attempt.

Non-AAA enforcement (often called Web-based authentication or MAC-based profiling without 802.1X ) is chosen for ease of deployment. 802.1X is highly secure but requires a "Supplicant" (software) configuration on every client device. By using a non-AAA method, the engineer can secure the network using the device's MAC address and a redirect to a web portal, which works on any device with a browser without needing to touch the client's internal network settings.

Network access devices, including Aruba Instant APs and controllers, generally require certificates in the PEM (Privacy Enhanced Mail) format. PEM certificates are Base64 encoded and are standard for Unix- based systems and networking hardware because they can easily include the entire trust chain (server, intermediate, and root certificates) in a single text file.