Interlogix NS3562-8P-2S, Руководство пользователя, Страница: 144 / 245

Chapter 4: Web configuration
142 NS3562-8P-2S User Manual
Authentication initiation and message exchange
The switch or the client can initiate authentication. If you enable authentication on a
port by using the dot1x port-control auto interface configuration command, the switch
must initiate authentication when it determines that the port link state transitions from
down to up. It then sends an EAP-request/identity frame to the client to request its
identity (typically, the switch sends an initial identity/request frame followed by one or
more requests for authentication information). Upon receipt of the frame, the client
responds with an EAP-response/identity frame. However, if the client does not receive
an EAP-request/identity frame from the switch during bootup, the client can initiate
authentication by sending an EAPOL-start frame, which prompts the switch to request
the client's identity.
If 802.1X is not enabled or supported on the network access device, any EAPOL
frames from the client are dropped. If the client does not receive an EAP-
request/identity frame after three attempts to start authentication, the client transmits
frames as if the port is in the authorized state. A port in the authorized state effectively
means that the client has been successfully authenticated.
When the client supplies its identity, the switch begins its role as the intermediary,
passing EAP frames between the client and the authentication server until
authentication succeeds or fails. If the authentication succeeds, the switch port is
authorized.
The specific exchange of EAP frames depends on the authentication method being
used. The diagram below shows a message exchange initiated by the client using the
One-Time-Password (OTP) authentication method with a RADIUS server.