User's Manual

User’s Manual of IGS-4215 Series
223
4.9.1.1 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.
Figure 4-9-1
 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.