TACACS is commonly used to determine user access rights and may be used with what for two-factor authentication?

• A. Password alone
• B. Biometric data only
• C. Username and password only
• D. Token, smart card, etc.

Answer: (D)

TACACS is about centralizing authentication, authorization, and accounting and it can work with multiple methods to verify a user. For two-factor authentication, you need two different kinds of credentials. A token or smart card represents something you have, which provides the second factor, and is commonly used with TACACS to achieve two-factor authentication when paired with a password or PIN.

Why the other options aren’t the best fit: a password alone is just one factor, so it can’t be two-factor by itself; username and password are two credentials but both are based on “something you know” and still count as a single factor; biometric data alone is also a single factor (something you are). The token or smart card option aligns with the two-factor idea by adding the separate factor of something you have.