sage The EAP-Method Identity message is used before or during the authentication phase. It is used to transport the supplicant's identity and, in some cases, during mutual authentication, the authenticator's identity. It can include data that will be presented to the user. Mutual Authentication The EAP-Method Identity message is carried by the EAP Request message for the identity request and then by the EAP Response message for the reply containing the identity. The EAP-Method Identity message is transferred to the authentication server. If the identity received is invalid, then this operation can be repeated several times. It is also possible for the authenticator to verify the supplicant's identity. 6.1.2.2. EAP-Method Notification message The EAP-Method Notification message is used before or during the authentication phase. It is used to transport information on authentication status. It includes data that will be presented to the user. The EAP-Method Notification message is carried by the EAP Request message for the notification request and then by the EAP Response message for the notification response. 6.1.2.3. EAP-Method Legacy NAK message The EAP-Method Legacy NAK message is used by the supplicant to indicate that it does not support the authentication method suggested by the authentication server. The EAP-Method Legacy NAK message is carried by the EAP Response message. It contains the authentication methods supported by the supplicant. If the message contains a Type field equal to ZERO, this means that the supplicant rejects the suggestion and that there is no alternative. The EAP-Method Expanded NAK message is used by the supplicant in response to a request that also contains the EAP-Method Expanded NAK message. This functionality enables the number of types of authentication methods to be expanded beyond the 255 values allowed by the Type field. 6.1.3. RADIUS messages The RADIUS protocol is used for transporting EAP-Method messages between the authentication server and the authenticator (switch or acce