User guide

802.1X Overview Configuring 802.1X
page 21-4 OmniSwitch 6600 Family Network Configuration Guide April 2005
802.1X Overview
The 802.1X standard defines port-based network access controls, and provides the structure for authenti-
cating physical devices attached to a LAN. It uses the Extensible Authentication Protocol (EAP).
There are three components for 802.1X:
• The Supplicant—This is the device connected to the switch. The device may be connected directly to
the switch or via a point-to-point LAN segment. Typically the supplicant is a PC or laptop.
• The Authenticator Port Access Entity (PAE)—This entity requires authentication from the suppli-
cant. The authenticator is connected to the supplicant directly or via a point-to-point LAN segment.
The OmniSwitch acts as the authenticator.
• The Authentication Server—This component provides the authentication service and verifies the
credentials (username, password, challenge, etc.) of the supplicant. On the OmniSwitch, only RADIUS
servers are currently supported for 802.1X authentication.
Note. The OmniSwitch itself cannot be an 802.1X supplicant.
802.1X Port Behavior
Before any device is authenticated through an 802.1X port, the port will only process 802.1X frames (EAP
frames) from an unknown source.
When an EAP frame or an unknown source data frame is received from a supplicant, the switch sends an
EAP packet to request the supplicant’s identity. The supplicant then sends the information (an EAP
response), which is validated on an authentication server set up for authenticating 802.1X ports. The server
determines whether additional information (a challenge, or secret) is required from the supplicant.
After the supplicant is successfully authenticated, the MAC address of the supplicant is learned in the
appropriate VLAN depending on the following conditions:
• If the authentication server returned a VLAN ID, then the supplicant is assigned to that VLAN. All
subsequent traffic from the supplicant is then forwarded on that VLAN.
• If the authentication server does not return a VLAN ID, then the supplicant is classified by Group
Mobility and dynamically assigned to a VLAN or carried on the default VLAN for the 802.1X port.
802.1X Components
Supplicant
Authenticator PAE
RADIUS server
OmniSwitch
PC
login request
OmniSwitch 6648
OmniSwitch 6648
Authentication
Server
authentication
request
authorization
granted