Device Roles - Cisco Catalyst 4500 series Administration Manual

Chapter 46 Configuring 802.1X Port-Based Authentication

Device Roles

With 802.1X port-based authentication, network devices have specific roles.
of each device, which is described below.
Figure 46-1
Workstations
Supplicants
•
•
Note
•
802.1X and Network Access Control
Network Access Control is a feature that allows port access policies to be influenced by the antivirus
posture of the authenticating device.
OL_28731-01
802.1X Device Roles
Client
Catalyst 4500 Network
Access Switch
Authenticator
Client—The workstation that requests access to the LAN, and responds to requests from the switch.
The workstation must be running 802.1X-compliant client software.
Authenticator—Controls physical access to the network based on the authentication status of the
client. The Catalyst 4500 series switch acts as an intermediary between the client and the
authentication server, requesting identity information from the client, verifying that information
with the authentication server, and relaying a response to the client. The switch encapsulates and
decapsulates the Extensible Authentication Protocol (EAP) frames and interacts with the RADIUS
authentication server.
When the switch receives EAPOL frames and relays them to the authentication server, the Ethernet
header is stripped and the remaining EAP frame is reencapsulated in the RADIUS format. The EAP
frames are not modified or examined during encapsulation, and the authentication server must
support EAP within the native frame format. When the switch receives frames from the
authentication server, the frame header is removed from the server, leaving the EAP frame, which
is then encapsulated for Ethernet and sent to the client.
The Catalyst 4500 series switches must be running software that supports the RADIUS client
and 802.1X.
Authentication server—Performs the actual authentication of the client. The authentication server
validates the identity of the client and notifies the switch that the client is authorized to access the
LAN and switch services. (The only supported authentication server is the RADIUS authentication
server with EAP extensions; it is available in Cisco Secure Access Control Server version 3.2 and
later releases.)
RADIUS
Authentication
server
Software Configuration Guide—Release IOS XE 3.6.0E and IOS 15.2(2)E
About 802.1X Port-Based Authentication
Figure 46-1 shows the role
46-3