Reference Guide

4. The authentication server replies with an Access-Challenge frame. The Access-Challenge frame requests that the

supplicant prove that it is who it claims to be, using a specified method (an EAP-Method). The challenge is

translated and forwarded to the supplicant by the authenticator.

5. The supplicant can negotiate the authentication method, but if it is acceptable, the supplicant provides the

Requested Challenge information in an EAP response, which is translated and forwarded to the authentication

server as another Access-Request frame.

6. If the identity information provided by the supplicant is valid, the authentication server sends an Access-Accept

frame in which network privileges are specified. The authenticator changes the port state to authorized and

forwards an EAP Success frame. If the identity information is invalid, the server sends an Access-Reject frame. If

the port state remains unauthorized, the authenticator forwards an EAP Failure frame.

Figure 8. EAP Port-Authentication

EAP over RADIUS

802.1X uses RADIUS to shuttle EAP packets between the authenticator and the authentication server, as defined in RFC

3579.

EAP messages are encapsulated in RADIUS packets as a type of attribute in Type, Length, Value (TLV) format. The Type

value for EAP messages is 79.