FGSW-2620VM User’s Manual
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 during bootup, the client does not receive an EAP-request/identity frame from the switch, the client can
initiate authentication by sending an EAPOL-start frame, which prompts the switch to request the client's identity.
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Notice:
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
becomes authorized.
The specific exchange of EAP frames depends on the authentication method being used. “Figure 2-43” shows a
message exchange initiated by the client using the One-Time-Password (OTP) authentication method with a RADIUS
server.
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