CompTIA Network+ N10-006 Q66

A technician has finished configuring AAA on a new network device. However, the technician is unable to log into the device with LDAP credentials but is able to do so with a local user account. Which of the following is the MOST likely reason for the problem?

A. Username is misspelled is the device configuration file
B. IDS is blocking RADIUS
C. Shared secret key is mismatched
D. Group policy has not propagated to the device

Correct Answer: C
Section: Network operations

AAA through RADIUS uses a Server Secret Key (a shared secret key). A secret key mismatch could cause login problems.
Authentication, authorization, and accounting (AAA) allows a network to have a single repository of user credentials. A network administrator can then, for example, supply the same credentials to log in to various network devices (for example, routers and switches). RADIUS and TACACS+ are protocols commonly used to communicate with an AAA server.