NTP and ccm cluster

[ciscoforum]

We are using an external server as NTP source for CCM. We modified ntp.conf file and now both servers are synced with the external source. My question what the recommended way for subscriber server? should I just keep the current config in the ntp.conf file which by default it gets clock from pub,or I also change the sub pointing to the external source?Thanks

[Steven Smith]

http://www.cisco.com/en/US/products/sw/voicesw/ps556/products_configuration_example09186a008009470f.shtml#maintask1

From the doc:

Please note that you cannot use NTP to synchronize between two Cisco CallManagers. The NTP that is installed in Cisco CallManager is a client NTP service and only synchronizes to an NTP server.

You should use the external source for both.

[koksiong]

Actually, this information may be outdated. My new publisher is definitely running a ntp server and the default install of any subscriber will point the ntp service to get their clock from the publisher.

I have no official doc to back this up though.

[jleon22]

Out of the box, the subscriber is set to attempt to try to sync with the publisher. So, it looks like maybe as of CCM 4.x that the publisher can serve ntp now.

You can verify that after a clean subscriber install of CCM 4.x that the ntp.conf file points to the publisher.

So, basically, you only need to set up the ntp.conf on the pub.

jleon