VigorSwitch P2260 User’s Guide
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The figure below shows the procedure of 802.1X authentication.
There are steps for the login based on 802.1X port access control management. The
protocol used in the right side is EAPOL and the left side is EAP.
1.
At the initial stage, the supplicant A is unauthenticated and a port on switch acting as
an authenticator is in unauthorized state. So the access is blocked in this stage.
2.
Initiating a session. Either authenticator or supplicant can initiate the message
exchange. If supplicant initiates the process, it sends EAPOL-start packet to the
authenticator PAE and authenticator will immediately respond EAP-Request/Identity
packet.
3.
The authenticator always periodically sends EAP-Request/Identity to the supplicant
for requesting the identity it wants to be authenticated.
4.
If the authenticator doesn’t send EAP-Request/Identity, the supplicant will initiate
EAPOL-Start the process by sending to the authenticator.
5.
And next, the Supplicant replies an EAP-Response/Identity to the authenticator. The
authenticator will embed the user ID into Radius-Access-Request command and send
it to the authentication server for confirming its identity.
6.
After receiving the Radius-Access-Request, the authentication server sends
Radius-Access-Challenge to the supplicant for asking for inputting user password via
the authenticator PAE.
7.
The supplicant will convert user password into the credential information, perhaps, in
MD5 format and replies an EAP-Response with this credential information as well as
the specified authentication algorithm (MD5 or OTP) to Authentication server via the
authenticator PAE. As per the value of the type field in message PDU, the
authentication server knows which algorithm should be applied to authenticate the
credential information, EAP-MD5 (Message Digest 5) or EAP-OTP (One Time
Password) or other else algorithm.
8.
If user ID and password is correct, the authentication server will send a
Radius-Access-Accept to the authenticator. If not correct, the authentication server
will send a Radius-Access-Reject.
9.
When the authenticator PAE receives a Radius-Access-Accept, it will send an
EAP-Success to the supplicant. At this time, the supplicant is authorized and the port
