Which RADIUS attribute can you use to filter MAB requests in an 802.1x deployment?

RADIUS attribute 1 is `User-Name`, which typically carries the MAC address itself for MAB, but it doesn't inherently filter the *type* of MAB request.

RADIUS attribute 6, known as `Service-Type`, can be used to distinguish between different types of authentication requests, including MAC Authentication Bypass (MAB). Specifically, for MAB, the `Service-Type` is typically set to `Call-Check`, allowing the RADIUS server to apply specific policies or filters based on this attribute type.

RADIUS attribute 31 is `Calling-Station-Id`, which carries the MAC address of the supplicant or device in MAB, but it does not filter the *type* of authentication request.

RADIUS attribute 2 is `User-Password`, which is not relevant for filtering MAB requests as MAB does not use a password.