User's Manual

User’s Manual of SGS-5240 Series Managed Switch
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 Remote Authentication Dial-in User Service (RADIUS)
 Terminal Access Controller Access Control System Plus (TACACS+)
 Local user name and Privilege Level control
RADIUS and TACACS+ are logon authentication protocols that use software running on a central server to control access to
RADIUS-aware or TACACS-aware devices on the network. An authentication server contains a database of multiple user
name / password pairs with associated privilege levels for each user that requires management access to the SGS-5240 Series
PoE Switch.
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.)