Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) — Question 311

Why is the keyword none needed when implementing management plane security using TACACS+?

Answer options

• A. It allows the local database to authenticate when the TACACS+ server is unreachable
• B. It allows the router to query a RADIUS server when the TACACS+ server is unreachable
• C. It prevents all users from accessing router 1 unless the TACACS+ server is reachable
• D. It allows authentication to succeed when the TACACS+ server is unreachable

Correct answer: D

Explanation

The keyword none is essential because it allows the device to authenticate users locally if the TACACS+ server is unavailable, ensuring that access is maintained. Option A is incorrect because it specifically refers to local database authentication, which is covered by the keyword none. Option B is wrong as it mentions RADIUS servers, which are not related to TACACS+. Option C is incorrect because it suggests that access is entirely denied, which is not the case with the use of the keyword none.