Question 280
An administrator reviewing a Cisco ISE deployment identifies: A replacement router sends TACACS+ requests to a reachable ISE service but every login fails after a network-device template copied the wrong shared secret. Which supported configuration change best meets the stated requirement?
Explanation
Correct Answer
The underlying cause is: TACACS+ requests must come from a recognized NAD with compatible shared secret, source identity and device administration service configuration. The correct response is: Correct the router's source address and TACACS+ shared secret to match the authorized ISE network device definition and retest login. Confirm by checking: A known approved administrator authenticates through the replacement router and an invalid client or secret remains rejected.
Incorrect Answers
That intervention addresses aaa local fallback during ise outage, where Administrative AAA needs a tightly controlled fallback access design for total external server unavailability without broadly bypassing central policy in normal operation. Here, the relevant failure is instead: TACACS+ requests must come from a recognized NAD with compatible shared secret, source identity and device administration service configuration.
That intervention addresses investigating tacacs command authorization denial, where Successful TACACS+ authentication does not prove command authorization: shell profile, command set, identity group, and matched device policy may independently restrict commands. In this question the necessary remedy is “Correct the router's source address and TACACS+ shared secret to match the authorized ISE network device definition and retest login”, which this alternative does not provide.
That intervention addresses tacacs device administration license entitlement, where ISE TACACS+ device administration requires the relevant enabled licensing entitlement and service activation, beyond ordinary RADIUS NAC capabilities. The observed condition is a replacement router sends TACACS+ requests to a reachable ISE service but every login fails after a network-device template copied the wrong shared secret; this mechanism addresses another problem.