You are asked to establish authentication for users connecting to the corporate network.

In this scenario, the requirement is to authenticate devices based on theirMAC addressesusing acentralized database.

MAC RADIUS (Option A):This is the standard Juniper method for authenticating "headless" or non-802.1X capable devices based on their hardware (MAC) address. The switch acts as a proxy, sending the device's MAC address as the username and password to a centralizedRADIUS server(the centralized database). If the MAC address is found in the server's database, the device is granted access to the network. This perfectly matches the user's requirement for MAC-based authentication and a centralized database.

Captive Portal (Option B):This is a web-based authentication method requiring user interaction (login via a browser), which is not based on MAC address identification for the initial authentication phase.

Supplicant Modes (Options C & D):These definehowmultiple devices are handled on an 802.1X-enabled port, but they are not authentication methods themselves; they rely on 802.1X (EAP-based) or MAC-RADIUS being already configured.