350-401 Question 192
Single answerA network engineer is troubleshooting an issue where devices on a network are experiencing time synchronization problems. The network uses NTP to synchronize device clocks. Upon examining the configuration on a core router, the following commands are found:
ntp server 192.168.1.1 prefer
ntp authenticate
ntp authentication-key 1 md5 cisco123
ntp trusted-key 1
After reviewing these commands, what could be the reason some devices are not synchronizing correctly with the NTP server?
- A
The 'prefer' keyword causes the router to ignore other NTP servers.
- B
The 'ntp authenticate' command is missing the correct trusted key configuration for the devices.
- C
The password used in 'ntp authentication-key' does not match the one configured on the NTP server.
- D
Devices are not configured to use NTP authentication.
Show answer and explanation
Correct answer: C
Explanation
The configuration provided indicates that the NTP server requires authentication using a specific key and password. If the password ('cisco123' in this case) does not match the one configured on the NTP server, devices will fail to authenticate and synchronize. Ensuring that the password matches on both the server and the clients is critical for successful time synchronization when NTP authentication is enabled.
- A. Incorrect.
The 'prefer' keyword does not cause the router to ignore other NTP servers. It simply marks the specified server as preferred for synchronization.
- B. Incorrect.
The 'ntp authenticate' command is correctly configured along with the trusted key. This is not the cause of the issue.
- C. Correct.
The password used in 'ntp authentication-key' must match on both the server and the clients. If it does not match, devices cannot authenticate and synchronize.
- D. Incorrect.
While NTP authentication is optional, if it is configured on the server, devices must also be configured for authentication. However, the scenario does not specify whether devices are configured for authentication.