802.1X architecture
802.1X operates in the client/server model. As shown in Figure 29, 802.1X authentication includes the following entities:
Client (supplicant)—A user terminal seeking access to the LAN. The terminal must have 802.1X software to authenticate to the access device.
Access device (authenticator)—Authenticates the client to control access to the LAN. In a typical 802.1X environment, the access device uses an authentication server to perform authentication.
Authentication server—Provides authentication services for the access device. The authentication server first authenticates 802.1X clients by using the data sent from the access device. Then, the server returns the authentication results to the access device to make access decisions. The authentication server is typically a RADIUS server. In a small LAN, you can use the access device as the authentication server.
Figure 28: 802.1X architecture
