A. TACACS+ is the only supported authentication server type.
B. If a host initiates the authentication process and does not receive a response， it assumes it is  not authorized.
C. RADIUS is the only supported authentication server type.
D. Before transmitting data， an 802.1x host must determine the authorization state of the switch.
E. Hosts are required to havea 802.1x authentication client or utilize PPPoE.
F. None of the other alternatives apply.

A. The switch will uniquely authorize the client by using the client MAC address.
B. The switch will cause the port to remain in the unauthorized state， ignoring all attempts by the  client to authenticate.
C. The switch port will disable 802.1x port-based authentication and cause the port to transition to  the authorized state without any further authentication exchange.
D. The switch port will enable 802.1x port-based authentication and begin relaying authentication  messages between the client and the authentication server.