Chapter 31 Configuring 802.1X Authentication; Understanding How 802.1X Authentication Works - Cisco WS-C2948G-GE-TX Configuration Manual

Configuring 802.1x Authentication
This chapter describes how to configure 802.1x authentication on the Catalyst enterprise LAN switches.
For complete syntax and usage information for the commands that are used in this chapter, refer to the
Note
Catalyst 4500 Series, Catalyst 2948G, Catalyst 2948G-GE-TX, and Catalyst 2980G Switches Command
Reference publication.
Note For information on configuring ports to allow or restrict traffic that is based on host MAC addresses, see
Chapter 16,
For information on configuring authentication, authorization, and accounting (AAA) to monitor and
Note
control access to the command-line interface (CLI) on the Catalyst enterprise LAN switches, see
Chapter 30,
This chapter consists of these sections:
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Understanding How 802.1x Authentication Works

IEEE 802.1x is a client-server-based access control and authentication protocol that restricts
unauthorized devices from connecting to a local area network (LAN) through publicly accessible ports.
802.1x authenticates each user device that is connected to a switch port before making available any
services that are offered by the switch or the LAN. Until the device is authenticated, 802.1x access
control allows only Extensible Authentication Protocol over LAN (EAPOL) traffic through the port to
which the device is connected. After authentication is successful, normal traffic can pass through the
port.
802.1x controls network access by creating two distinct virtual access points at each port. One access
point is an uncontrolled port; the other is a controlled port. All traffic through the single port is available
to both access points. Only EAPOL traffic is allowed to pass through the uncontrolled port, which is
Catalyst 4500 Series, Catalyst 2948G, Catalyst 2948G-GE-TX, and Catalyst 2980G Switches Software Configuration Guide—Release 8.2GLX
78-15908-01
"Configuring Port Security."
"Configuring the Switch Access Using AAA."
Understanding How 802.1x Authentication Works, page 31-1
Authentication Default Configuration, page 31-9
Authentication Configuration Guidelines, page 31-9
Configuring 802.1x Authentication on the Switch, page 31-10
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