Network Defense Essentials (NDE) Practice Exam

What is the correct order of steps in TACACS+ authentication?

1. 1-3-2-4

2. 3-1-4-2

3. 2-3-4-1

4. 4-2-1-3

The correct answer is: 3-1-4-2

TACACS+ (Terminal Access Controller Access-Control System Plus) authentication follows a specific sequence of steps to ensure secure access control. The correct order of steps in the TACACS+ authentication process is critical for understanding how network devices authenticate users. In the suggested sequence of 3-1-4-2, the process begins with the client sending an authentication request to the TACACS+ server. This step is essential as it initiates the authentication process. Next, the server checks the user's credentials against its database in the first step, which is vital for verifying user identities. Following this, the server responds to the client with an authentication reply in step four, which informs the client whether the authentication was successful or not. The final step involves the client receiving the server response, determining whether to grant or deny access based on the provided information. This order accurately reflects the operational steps within TACACS+, where initiating the request, validating credentials, responding to the client, and finally processing the result constitutes the fundamental process of user authentication in network security. This understanding is crucial for implementing TACACS+ effectively in managing user access and enforcing security measures in a network environment.