350-401 Question 190
Select 3A network engineer is troubleshooting an issue with time synchronization in a Cisco enterprise network. The NTP configuration on a router shows the following command: ntp server 192.168.1.1 prefer. However, the router is not synchronizing with the NTP server. Which of the following possible causes should the engineer investigate?
- A
The NTP server 192.168.1.1 is unreachable from the router.
- B
The NTP authentication key is incorrectly configured on the router.
- C
No 'ntp master' command is configured on the router.
- D
The 'ntp server 192.168.1.1 prefer' command is configured incorrectly.
- E
The router’s clock is synchronized with another NTP server with a lower stratum value.
Show answer and explanation
Correct answers: A, B, E
Explanation
When troubleshooting NTP synchronization issues, it is essential to check connectivity to the NTP server, the correct configuration of any required authentication keys, and whether the router is already synchronized with a more accurate server. The 'ntp master' command and the syntax of the 'ntp server' command are not relevant in this scenario, as the router is functioning as an NTP client.
- A. Correct.
If the NTP server is unreachable, the router will not be able to synchronize with it. This is a fundamental issue to investigate.
- B. Correct.
NTP authentication ensures secure communication between the NTP server and the client. If the authentication key is misconfigured, synchronization will fail.
- C. Incorrect.
The 'ntp master' command is used to configure a device as an NTP server, not a client. It is irrelevant in this scenario since the router is intended to synchronize with an external server.
- D. Incorrect.
The 'ntp server 192.168.1.1 prefer' command is correct and prioritizes the specified server during synchronization. There is no issue with the command itself.
- E. Correct.
If the router is already synchronized with another NTP server with a lower stratum value (indicating higher accuracy), it may not switch to the preferred server.