Cisco 3750G Configuration Guide - Page 255

10 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 3750 switch. IEEE 802.1x authentication prevents unauthorized devices (clients) from gaining access to the network. Unless otherwise noted, the term switch refers to a standalone switch and to a switch stack. Note For complete syntax and usage information for the commands used in this chapter, see the "RADIUS Commands" section in the Cisco IOS Security Command Reference, Release 12.2 and in the command reference for this release. This chapter consists of these sections: • Understanding IEEE 802.1x Port-Based Authentication, page 10-1 • Configuring IEEE 802.1x Authentication, page 10-21 • Displaying IEEE 802.1x Statistics and Status, page 10-46 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 10-2 • Authentication Process, page 10-3 • Authentication Initiation and Message Exchange, page 10-5 • Ports in Authorized and Unauthorized States, page 10-7 • IEEE 802.1x Authentication and Switch Stacks, page 10-8 • IEEE 802.1x Host Mode, page 10-8 OL-8550-02 Catalyst 3750 Switch Software Configuration Guide 10-1