Specifications

CHAPTER

10-1

Catalyst 2950 and Catalyst 2955 Switch Software Configuration Guide

78-11380-07

Configuring 802.1X Port-Based Authentication

This chapter describes how to configure IEEE 802.1X port-based authentication on your Catalyst 2950

or Catalyst 2955 switch to prevent unauthorized devices (clients) from gaining access to the network.

Note For complete syntax and usage information for the commands used in this chapter, refer to the command

reference for this release.

This chapter consists of these sections:

• Understanding 802.1X Port-Based Authentication, page 10-1

• Configuring 802.1X Authentication, page 10-7

• Displaying 802.1X Statistics and Status, page 10-16

Understanding 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.

These sections describe 802.1X port-based authentication:

• Device Roles, page 10-2

• Authentication Initiation and Message Exchange, page 10-3

• Ports in Authorized and Unauthorized States, page 10-4

• Voice VLAN Ports, page 10-5

• Using 802.1X with Port Security, page 10-5

• Using 802.1X with VLAN Assignment, page 10-6

• Supported Topologies, page 10-7