Chapter2.TACACS and RADIUS

Chapter 2. TACACS+ and RADIUS

In this chapter, you learn the following topics:

• A brief overview of TACACS+

• A brief overview of RADIUS

• TACACS+ in detail

• RADIUS in detail

In the authentication arena, an authentication, authorization, and accounting (AAA) client can use multiple protocols to communicate with an AAA server. These are protocols such as TACACS, XTACACS, TACACS+, and RADIUS. This chapter focuses on two of these protocols, Terminal Access Controller Access Control System Plus (TACACS+) and Remote Authentication Dial-In User Service (RADIUS). Specifically, you see the differences between the two, situations that warrant the use of either, and the underlying concepts of each.

When you are done with this chapter, you will find that, while both TACACS+ and RADIUS end up with the same result in general, the underlying architecture is quite different between the two.