Chapter 3. Access Control

As discussed in the previous chapter, you can configure a Cisco device through the console port or through remote access, such as Telnet or SSH. However, to prevent unauthorized use, such access to the devices should be controlled. This chapter covers the tools that control and record administrative access to Cisco devices. The three functions of securing access to a Cisco device, controlling user activity, and recording user activity are together known as authentication, authorization, and accounting or AAA. Terminal Access Controller Access Control System Plus (TACACS+) and Remote Authentication Dial-In User Service (RADIUS) are the two protocols for implementing the AAA technology framework.

Based on the protocols used by AAA, this chapter consists of the following three parts:

• Overview of AAA technology

• Using TACACS+ for AAA

• Using RADIUS for AAA