メインコンテンツまでスキップ

Unable to contact NTP servers

Important

  • If at least one of the controller's management ports are configured via DHCP, the controller may be able to automatically detect NTP and DNS servers from your DHCP server.

  • If neither of the management ports are configured via DHCP, or you do not wish the controller to use the NTP or DNS servers from your DHCP server's configuration, you may provide static addresses for the controller to use instead.

  • If a static domain name is provided for an NTP server, a DNS server must also be configured on the same controller to resolve the server's IP address. You may configure a DNS server for the controller by going to Hardware, highlighting the desired controller, and selecting Configure DNS Server.

Recovery Steps​

  1. Check if the affected controller is configured to automatically obtain NTP server addresses from a DHCP server.

    1. Go to Hardware.

    2. Highlight the affected controller shown in the Details area. The controller is located on the backside of the controller shelf.

    3. Select Configure NTP server.

    Is the controller configured to automatically obtain NTP server addresses from a DHCP server?

    • If yes, go to step 2.

    • If no, go to step 8.

  2. Is the controller detecting any NTP servers from your DHCP server?

    • If yes, go to step 3.

    • If no, go to step 5.

  3. Are the detected addresses correct?

    • If yes, go to step 4.

    • If no, fix the problem, and then go to step 20.

  4. Are the NTP servers operational and reachable from the controller given your network configuration?

    • If yes, contact your Technical Support Engineer.

    • If no, fix the problem, and then go to step 20.

  5. Is at least one of the controller's management ports configured via DHCP?

    • If yes, go to step 6.

    • If no, go to step 7.

  6. Add at least one NTP server to your DHCP server's configuration or specify at least one static NTP server address, and then go to step 20.

  7. Specify at least one static NTP server address, and then go to step 20.

  8. Are the provided addresses correct?

    • If yes, go to step 9.

    • If no, fix the problem, and then go to step 20.

  9. Are the NTP servers operational and reachable from the controller given your network configuration?

    • If yes, go to step 10.

    • If no, fix the problem, and then go to step 20.

  10. Are the provided addresses domain names?

    • If yes, go to step 11.

    • If no, contact your Technical Support Engineer.

  11. Check if the controller is configured to automatically obtain DNS server addresses from a DHCP server.

    1. Go to Hardware.

    2. Highlight the controller listed in the Details area.

    3. Select Configure DNS server.

    Is the controller configured to automatically obtain DNS server addresses from a DHCP server?

    • If yes, go to step 12.

    • If no, go to step 18.

  12. Is the controller detecting any DNS servers from your DHCP server?

    • If yes, go to step 13.

    • If no, go to step 15.

  13. Are the detected addresses correct?

    • If yes, go to step 14.

    • If no, fix the problem, and then go to step 20.

  14. Are the DNS servers operational and reachable from the controller given your network configuration?

    • If yes, contact your Technical Support Engineer.

    • If no, fix the problem, and then go to step 20.

  15. Is at least one of the controller's management ports configured via DHCP?

    • If yes, go to step 16.

    • If no, go to step 17.

  16. Add at least one DNS server to your DHCP server's configuration or specify at least one static DNS server address, and then go to step 20.

  17. Specify at least one static DNS server address, and then go to step 20.

  18. Are the provided addresses correct?

    • If yes, go to step 19.

    • If no, fix the problem, and then go to step 20.

  19. Are the DNS servers operational and reachable from the controller given your network configuration?

    • If yes, go to step 20.

    • If no, fix the problem, and then go to step 20.

  20. Wait one hour for the controller to re-query the specified NTP servers. If the failure does not disappear after one hour, recheck the controller's NTP and DNS configuration and then contact your Technical Support Engineer.