Selected Answer: D This is a sample debug output from the Router, when the TACACS server is configured with the wrong pre shared key: ... *Apr 6 13:35:07.886: TPLUS: received bad AUTHEN packet: length = 6, expected 43974 *Apr 6 13:35:07.886: TPLUS: Invalid AUTHEN packet (check keys). https://www.cisco.com/c/en/us/support/docs/security-vpn/terminal-access-controller-access-control-system-tacacs-/200467-Troubleshoot-TACACS-Authentication-Issue.html

Selected Answer: D D. bash Copy code R1(config)# tacacs server prod R1(config-server-tacacs)# key cisco123 This configuration sets up the TACACS+ server named "prod" with the key "cisco123". Make sure the key configured on the router matches the key configured on the TACACS+ server. Also, ensure that the TACACS+ server is reachable and properly configured to handle authentication requests from the router.

Selected Answer: D Right

Please explain. I can't understand.

the key is "(check key)" so the issue is the credential!

look at the last line in the log, it says check key. so the issue is with the credentials

Selected Answer: D The log message "TPLUS: Invalid AUTHEN packet (check keys)" from the exhibit points to a problem with the shared secret between the client and server. TACACS+ uses symmetric-key cryptography. The authenticated client in our example used a different encryption key than the server's. Option 'C' makes sure that both the client and the server encrypt their messages with the same key (shared secret, or a.k.a. a pre-configured key.)

Selected Answer: D The last line of the exhibit says, "Check keys," which means you need to change the key (the keys do not match between client and server)