Vidipac VSW7242, User Manual, Page: 58 / 288

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Port
The port number for which the configuration below applies.
Admin State
If NAS is globally enabled, this selection controls the port's authentication mode. The following modes are
available:
Force Authorized
In this mode, the switch will send one EAPOL Success frame when the port link comes up, and any client
on the port will be allowed network access without authentication.
Force Unauthorized
In this mode, the switch will send one EAPOL Failure frame when the port link comes up, and any client
on the port will be disallowed network access.
Port
-
based 802.1X
In the 802.1X-world, the user is called the supplicant, the switch is the authenticator, and the RADIUS
server is the authentication server. The authenticator acts as the man-in-the-middle, forwarding requests
and responses between the supplicant and the authentication server. Frames sent between the
supplicant and the switch are special 802.1X frames, known as EAPOL (EAP Over LANs) frames.
EAPOL frames encapsulate EAP PDUs (RFC3748). Frames sent between the switch and the RADIUS
server are RADIUS packets. RADIUS packets also encapsulate EAP PDUs together with other attributes
like the switch's IP address, name, and the supplicant's port number on the switch. EAP is very flexible, in
that it allows for different authentication methods, like MD5-CHALLENGE, PEAP, and TLS. The important
thing is that the authenticator (the switch) doesn't need to know which authentication method the
supplicant and the authentication server are using, or how many information exchange frames are
needed for a particular method. The switch simply encapsulates the EAP part of the frame into the
relevant type (EAPOL or RADIUS) and forwards it.
When authentication is complete, the RADIUS server sends a special packet containing a success or
failure indication. Besides forwarding this decision to the supplicant, the switch uses it to open up or block
traffic on the switch port connected to the supplicant.