Which statement about 802.1x port-based authentication is true?
A.
Hosts are required to have an 802.1x authentication client or utilize PPPoE.
B.
Before transmitting data, an 802.1x host must determine the authorization state of the
switch.
C.
RADIUS is the only supported authentication server type.
D.
If a host initiates the authentication process and does not receive a response, it assumes
it is not authorized.
Explanation:
The IEEE 802.1x standard defines a port-based access control and authentication protocol
that restricts unauthorized workstations from connecting to a LAN through publicly
accessible switch ports. The authentication server authenticates each workstation that is
connected to a switch port before making available any services offered by the switch or the
LAN. Until the workstation is authenticated, 802.1x access control allows only Extensible
Authentication Protocol over LAN (EAPOL) traffic through the port to which the workstation is
connected. After authentication succeeds, normal traffic can pass through the port.
Authentication server: Performs the actual authentication of the client. The authentication
server validates the identity of the client and notifies the switch whether or not the client is
authorized to access the LAN and switch services. Because the switch acts as the proxy, the
authentication service is transparent to the client. The RADIUS security system with
Extensible Authentication Protocol (EAP) extensions is the only supported authentication server.
Reference:
Configuring 802.1X Port-Based Authentication
(http://www.cisco.com/en/US/docs/switches/lan/catalyst3560/software/release/12.2_55_se/configuration/guide/sw8021x.html)