Cisco WS-C2960-24TC-S Software Guide - Page 181

9 C H A P T E R Configuring IEEE 802.1x Port-Based Authentication This chapter describes how to configure IEEE 802.1x port-based authentication on the Catalyst 2960 switch. IEEE 802.1x authentication prevents unauthorized devices (clients) from gaining access to the network. Note For complete syntax and usage information for the commands used in this chapter, see the command reference for this release and the "RADIUS Commands" section in the Cisco IOS Security Command Reference, Release 12.2 from the Cisco.com page under Documentation > Cisco IOS Software > 12.2 Mainline > Command References. This chapter consists of these sections: • Understanding IEEE 802.1x Port-Based Authentication, page 9-1 • Configuring IEEE 802.1x Authentication, page 9-18 • Displaying IEEE 802.1x Statistics and Status, page 9-41 Understanding IEEE 802.1x Port-Based Authentication The IEEE 802.1x standard defines a client-server-based access control and authentication protocol that prevents clients from connecting to a LAN through publicly accessible ports unless they are authenticated. 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, IEEE 802.1x access control allows only Extensible Authentication Protocol over LAN (EAPOL), Cisco Discovery Protocol (CDP), and Spanning Tree Protocol (STP) traffic through the port to which the client is connected. After authentication, normal traffic can pass through the port. These sections describe IEEE 802.1x port-based authentication: • Device Roles, page 9-2 • Authentication Process, page 9-3 • Authentication Initiation and Message Exchange, page 9-5 • Ports in Authorized and Unauthorized States, page 9-7 • IEEE 802.1x Host Mode, page 9-7 OL-8603-04 Catalyst 2960 Switch Software Configuration Guide 9-1