Figure 4. EAP Frames Encapsulated in Ethernet and RADUISThe authentication process involves three devices:• The device attempting to access the network is the supplicant. The supplicant is not allowed tocommunicate on the network until the authenticator authorizes the port. It can only communicatewith the authenticator in response to 802.1X requests.• The device with which the supplicant communicates is the authenticator. The authenticator is thegate keeper of the network. It translates and forwards requests and responses between theauthentication server and the supplicant. The authenticator also changes the status of the port basedon the results of the authentication process. The Dell Networking switch is the authenticator.• The authentication-server selects the authentication method, verifies the information the supplicantprovides, and grants it network access privileges.Ports can be in one of two states:• Ports are in an unauthorized state by default. In this state, non-802.1X traffic cannot be forwarded inor out of the port.• The authenticator changes the port state to authorized if the server can authenticate the supplicant.In this state, network traffic can be forwarded normally.NOTE: The Dell Networking switches place 802.1X-enabled ports in the unauthorized state bydefault.Port-Authentication ProcessThe authentication process begins when the authenticator senses that a link status has changed fromdown to up:1. When the authenticator senses a link state change, it requests that the supplicant identify itself usingan EAP Identity Request frame.2. The supplicant responds with its identity in an EAP Response Identity frame.802.1X 83
