Configuration; Understanding Ieee 802.1X Port-Based Authentication - Planet FGSD-1022P User Manual

4.12 802.1X Configuration
802.1x is an IEEE authentication specification which prevents the client from accessing a wireless access point or wired
switch until it provides authority, like the user name and password that are verified by an authentication server (such as
RADIUS server).

4.12.1 Understanding IEEE 802.1X Port-Based Authentication

The IEEE 802.1X standard defines a client-server-based access control and authentication protocol that restricts
unauthorized clients from connecting to a LAN through publicly accessible ports. The authentication server authenticates
each client connected to a switch port before making available any services offered by the switch or the LAN.
Until the client is authenticated, 802.1X access control allows only Extensible Authentication Protocol over LAN
(EAPOL) traffic through the port to which the client is connected. After authentication is successful, normal traffic can pass
through the port.
This section includes this conceptual information:
 Device Roles
 Authentication Initiation and Message Exchange
 Ports in Authorized and Unauthorized States

Device Roles
With 802.1X port-based authentication, the devices in the network have specific roles as shown below.
Client—the device (workstation) that requests access to the LAN and switch services and responds to requests from the
switch. The workstation must be running 802.1X-compliant client software such as that offered in the Microsoft Windows XP
operating system. (The client is the supplicant in the IEEE 802.1X specification.)
 Authentication server—performs the actual authentication of the client. The authentication server validates the
identity of the client and notifies the switch whether or not the client is authorized to access the LAN and switch
services. Because the switch acts as the proxy, the authentication service is transparent to the client. In this release,
the Remote Authentication Dial-In User Service (RADIUS) security system with Extensible Authentication
Protocol (EAP) extensions is the only supported authentication server; it is available in Cisco Secure Access
Figure 4-12-1: 802.1x device role
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