Remove NTP from CUCM

[Syed]

Dear All,

A quick question.

I want to remove an NTP reference from CUCM which is not in use from long time now, may I know the best & easiest method to trace the dependency and remove it safely?

CUCM Version: 9.1.2

For your information, I am not seeing this particular IP address in OS administration NTP server list.

Regards,

Syed Mujaheer

[Jitender Bhandari]

Hi Syed,

Are you saying you can see the server in "utils ntp server list" on CLI. BUt it is not seeing under OS admin Settings -> NTP Server?

JB

[Syed]

Hi JB,

No, let me put it in a better way.

I have 2 NTP servers in the network and I am seeing them at both places (CLI & OS admin).

I had another NTP server in the same network but it is not there now, so I want to remove the 3^rd server from the CUCM.

The problem is date & time has this server in NTP reference list and it is mapped to device pools. So if I remove it and hit save & reset the dependent device pools will also reset, correct me if I am wrong. Likewise there might other place in call manager which are depending on this.

I would like to remove cautiously.

Find attached screenshot.

Regards,

Syed

[Aman Soi]

Hi,

If u have NTP servers syncronised,then,u can delete this one .

In short, u need to have at least one NTP server synchronized to delete the second NTP.

regds,

aman

[Syed]

Hi Aman,

May I know what could be the impact if I remove this IP address from CMLocal NTP reference list?

[Aman Soi]

Hi Syed,

there won"t be any impact since ntp server to be removed us in unsyncronised state and other two are working fine.

regds,

aman

[Syed]

Hi Aman,

When I remove this NTP reference from date/time groups and hit save & reset/apply config does it make the phones restart?

Regards,

Syed

[Jonathan Schulenberg · Accepted solution]

Yes, it's likely to restart the phones but if it doesn't you should use Apply Config and Reset (not Restart) to ensure phones get this updated setting in their XML file (which is only parsed upon a Reset). Until this happens the phones will continue sending packets to a no longer existent NTP server attempting to synchronize.

[Syed]

Thank you Aman & Jonathan...

[pedro.alexandre]

Hi Jonathan !  

I need to change the ntp server from a specific cucm server but I'm not sure about the impact.

Do you know if the ip phone are automatic restart after apply this change ? 

Thank you in advance !

[Nadav]

Hi,

There is a difference between the NTP server for the OS and the NTP servers that are part of the device pool (Date/Time Groups are assigned to device pools). You need to remove the NTP server from each of the Date/Time Groups before you can remove the NTP server from the OS. Just feel free not to apply config after you save changes.

You should check out:
https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/10_0_1/ccmcfg/CUCM_BK_C95ABA82_00_admin-guide-100/CUCM_BK_C95ABA82_00_admin-guide-100_chapter_0110.pdf

[Jaime Valencia]

AFAIK there is no such dependency, the Phone NTP Reference is only used by phones, if you configure it, it can fallback to the system time, provided by the NTP you configure in the OS. And they're handled independently:

If you want to do so, you can configure phone Network Time Protocol (NTP) references in Cisco Unified Communications Manager Administration to ensure that a phone that is running SIP gets its date and time from the NTP server. If all NTP servers do not respond, the phone that is running SIP uses the date header in the 200 OK response to the REGISTER message for the date and time.

After you add the phone NTP reference to Cisco Unified Communications Manager Administration, you must add it to a date/time group. In the date/time group, you prioritize the phone NTP references, starting with the first server that you want the phone to contact.

The date/time group configuration gets specified in the device pool, and the device pool gets specified on the phone page.

I have added and changed NTPs in my lab and I don't recall any phone reset, if there's a delta between the current time and the NTP, phones will get it without a reset.

[Aman Soi]

Hi Syed,

I have never done from GUI.

you can try deleting ntp from CLI of Pub.

It won't restart phone

regds,

aman

[Jonathan Schulenberg]

Aman-

I believe the OP is asking about the Phone NTP Reference within CUCM Administration that is relevant to the Date/Time Group and not the platform-level NTP configuration.

[Abhay Singh Reyal · Accepted solution]

In order to check the dependency of NTP follow the procedure mentioned in below link for 

Deleting the Phone NTP Reference

http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/7_1_2/ccmcfg/bccm-712-cm/b02ntpsv.html

Also,  you can check the status of NTP and servers from CLI as well.

In order to delete the desired one use below command. 

utils ntp server delete x.x.x.x

Hope this helps .

Regards

Abhay