CiscoSecure ACS and AAA
The feature and product this chapter discusses most is the CiscoSecure ACS. It is available on UNIX and Windows platforms, and is what provides a Cisco network with AAA capabilities. The CiscoSecure ACS has a graphical user interface (GUI) accessible from a Web browser. It is a highly scalable Web-based Java tool that allows multiple administrators to work with it simultaneously. Let's examine the three different AAA services in detail.
Authentication happens before a user is permitted onto the network. It is the ability to identify the user and determine whether he should be allowed.
Authorization is what a user is allowed to do on a network. You can control which protocols and services are permitted. You can also control what system levels and configuration modes the user can reach and what commands are available at that point.
Accounting allows an administrator to keep track of a number of things: the duration of a connection, the amount of traffic transmitted, and the commands entered on a device.