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Catalyst 3750-X and 3560-X Switch Software Configuration Guide
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Chapter 10 Configuring Switch-Based Authentication
Controlling Switch Access with TACACS+
Controlling Switch Access with TACACS+
This section describes how to enable and configure Terminal Access Controller Access Control System
Plus (TACACS+), which provides detailed accounting information and flexible administrative control
over authentication and authorization processes. TACACS+ is facilitated through authentication,
authorization, accounting (AAA) and can be enabled only through AAA commands.
Note For complete syntax and usage information for the commands used in this section, see the Cisco IOS
Security Command Reference, Release 12.2.
These sections contain this configuration information:
• Understanding TACACS+, page 10-10
• TACACS+ Operation, page 10-12
• Configuring TACACS+, page 10-12
• Displaying the TACACS+ Configuration, page 10-17

Understanding TACACS+

TACACS+ is a security application that provides centralized validation of users attempting to gain access
to your switch. TACACS+ services are maintained in a database on a TACACS+ daemon typically
running on a UNIX or Windows NT workstation. You should have access to and should configure a
TACACS+ server before the configuring TACACS+ features on your switch.
Note We recommend a redundant connection between a switch stack and the TACACS+ server. This is to help
ensure that the TACACS+ server remains accessible in case one of the connected stack members is
removed from the switch stack.
TACACS+ provides for separate and modular authentication, authorization, and accounting facilities.
TACACS+ allows for a single access control server (the TACACS+ daemon) to provide each
service—authentication, authorization, and accounting—independently. Each service can be tied into its
own database to take advantage of other services available on that server or on the network, depending
on the capabilities of the daemon.
The goal of TACACS+ is to provide a method for managing multiple network access points from a single
management service. Your switch can be a network access server along with other Cisco routers and
access servers. A network access server provides connections to a single user, to a network or
subnetwork, and to interconnected networks as shown in Figure 10-1.