CCIE Security Exam Certification Guide

Authentication, Authorization, and Accounting (AAA)

Authentication, authorization, and accounting, (pronounced triple A) provides security to Cisco IOS routers and network devices beyond the simple user authentication available on IOS devices.

AAA provides a method to identify which users are logged into a router and each user's authority level. AAA also provides the capability to monitor user activity and provide accounting information.

In today's IP networks, access to network data is available in a variety of methods, including the following:

• PSTN Dialup modems

• ISDN dialup

• Access through the Internet through virtual private networks (VPNs)

The AAA model is defined as follows:

• Authentication— Who are you?

• Authorization— What resources are you ...