Re: Changing NTP on Call Manager 8.6

kwaldecker · ‎11-26-2012

Hello all,

I need to change the NTP server that is on the call manager. Its been awhile since i did one but wanted to check to see if there are any gotchas.

I know it will probably cause the licenses to go bad and have to be reissued.

There isn't a reboot or anything that has to be done is there? I don't think there is but want to verify

thanks

Rob Huffman · ‎11-26-2012

Hi Ken,

You will have to restart the other nodes

NTP Servers

Ensure that external NTP servers are stratum 9 or higher (1-9). To add, delete, or modify an external NTP server, follow this procedure:

Note You can only configure the NTP server settings on the first node or publisher.

Procedure

Step 1 From the Cisco Unified Communications Operating System Administration window, navigate to Settings > NTP Servers.

The NTP Server Settings window displays.

Step 2 You can add, delete, or modify an NTP server:

Note To avoid potential compatibility, accuracy, and network jitter problems, the external NTP servers that you specify for the primary node should be NTP v4 (version 4). If you are usingIPv6 addressing, external NTP servers must be NTP v4.

Note If you run Cisco Unified Communications Manager on a virtualized server and you change this value, you must obtain a replacement license file that is registered to the calculated license MAC based on the new value.

•To delete an NTP server, check the check box in front of the appropriate server and click Delete.

•To add an NTP server, click Add, enter the hostname or IP address, and then click Save.

•To modify an NTP server, click the IP address, modify the hostname or IP address, and then click Save.

Note Any change that you make to the NTP servers can take up to 5 minutes to complete. Whenever you make any change to the NTP servers, you must refresh the window to display the correct status.

Step 3 To refresh the NTP Server Settings window and display the correct status, choose Settings > NTP.

Note After deleting, modifying, or adding the NTP server, you must restart all other nodes in the cluster for the changes to take affect.

http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/cucos/8_6_1/cucos/iptpch4.html#wp1053371

Cheers!

Rob

"And if I should fall behind
Wait for me" - Springsteen

mahmoodmkl · ‎11-17-2013

Hi Rob,

Note

If you run Cisco Unified Communications Manager on a virtualized server and you change this value, you must obtain a replacement license file that is registered to the calculated license MAC based on the new value.

Does the above applies to physical servers..?

Thanks

kwaldecker · ‎11-18-2013

If its a physical server you do not need to get new licenses as the MAC address will not change

On physical servers the licenses use the actual Mac address of the server.

On the virtual servers the licenses use a License Mac address that is generated based on server setting

Joseph Martini · ‎11-18-2013

Correct, you do not need new licenses because the physical MAC address does not change.

kwaldecker · ‎11-26-2012

I think i found the answers

http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/cucos/8_6_1/cucos/iptpch4.html#wp1053371

However once you change the NTP do you immediately have to reset the subscribers in the cluster. or could you change the NTP today and reset the cluster over the weekend?

what would happen if you waited?

Joseph Martini · ‎11-18-2013

I would try your best to not wait. If you can reboot the servers over the weekend, I would change the NTP setting over the weekend too right before the reboot. If your servers become out of sync due to the NTP server change between themselves, replication is usually the first thing to break.