AAA stands for authentication, authorization, and accounting. The AAA feature, which is supported by almost every Cisco networking device currently on the market, allows for the centralized management of these features across the entire network. Here is a description of each of those three features.
Authentication requires users and administrators to prove that they really are who they say they are. Authentication is established using a username and password, challenge and response, token cards, and other methods.
After authenticating the user and administrator, authorization services decide which resources the user and administrator are allowed to access and which operations the user and administrator ...