In order to enhance security on the Company network, users must be authenticated using 802.1X. When authentication is required, where must 802.1X be configured in order to connect a PC to a switch?
A.
Switch port and local router port
B.
Switch port, client PC, and authentication server
C.
Client PC only
D.
Switch port only
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.
With 802.1x port-based authentication, the devices in the network have specific roles, as follows:
Client: The device (workstation) that requests access to the LAN and switch services, and responds to requests from the switch. The workstation must be running 802.1x-compliant client software, such as what is offered in the Microsoft Windows XP operating system. (The port that the client is attached to is the supplicant [client] in the IEEE 802.1x specification.)
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.
Switch(also called the authenticator): Controls physical access to the network based on the authentication status of the client. The switch acts as an intermediary (proxy) between the client (supplicant) and the authentication server, requesting identifying information from the client, verifying that information with the authentication server, and relaying a response to the client. The switch uses a RADIUS software agent, which is responsible for encapsulating and decapsulating the EAP frames and interacting with the authentication server.