This read-only integer reports which authentication method was actually used for this specific session: 802.1X EAPOL, MAC-based authentication, or web-based, captive portal, authentication. An administrator checks this to confirm which of a port's several enabled authentication methods a given client actually used, especially on ports configured to accept multiple methods. For example, on a port set to accept both MAC and EAPOL authentication, this OID lets the admin see whether a particular connected device authenticated via its 802.1X supplicant or fell back to MAC-based authentication.