A network administrator wants to configure 802.1x port-based authentication, however, the client
workstation is not 802.1x compliant. What is the only supported authentication server that can be
used?

A.
TACACS with LEAP extensions

B.
TACACS+

C.
RADIUS with EAP extensions

D.
LDAP

Explanation:
The IEEE 8021x 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.
With 802.1x port-based authentication, the devices in the network have specific roles as, as
follows:
Reference:
http://www.cisco.com/en/US/docs/switches/lan/catalyst2950/software/release/12.1_9_ea1/configur
ation/guide/Sw8021x.html