Dell PowerConnect 5548 User Guide - Page 128

The device supports Port Based Authentication via RADIUS servers. Dot1x Overview Dot1x is an IEEE standard for port-based network access control. The Dot1x framework enables a device (the supplicant) to request port access from a remote device (authenticator) to which it is connected. The supplicant is permitted to send data to the port only after it is authenticated and authorized. If it is not authenticated and authorized, the authenticator discards the supplicant data, unless the data is sent to a Guest VLAN and/or non-authenticated VLANs. Authentication of the supplicant is performed by an external RADIUS server through the authenticator. The authenticator monitors the results of the authentication. In the Dot1x standard, a device can be a supplicant and an authenticator at a port, simultaneously requesting and granting port access. However, this device can only act as an authenticator, and does not take on the role of a supplicant. The following varieties of Dot1x exist: • Single session Dot1x: - A1-Single-session/Single Host - In this mode, the switch, as an authenticator, supports a single Dot1x session, and grants permission to use the port to an authorized supplicant. All other access requests, made by other devices received from the same port, are denied until the authorized supplicant is no longer using the port, or the access request is to an unauthenticated or guest VLAN. - Single-session/Multiple Hosts-This follows the Dot1x standard. In this mode, the switch, as an authenticator, enables any device to use a port, as long as it has been granted permission as a supplicant at the port. • Multi-Session Dot1x-Every device (supplicant) connecting to a port must be authenticated and authorized by the switch (authenticator), separately in a different Dot1x session. This is the only mode that supports Dynamic VLAN Assignment (DVA). 128 Dell PowerConnect 55xx Systems User Guide