cucm 11.5 ntp windows

[abd88elhak]

 hi,

I have CUCM 11.5 and an IAD 2400 as ntp server, when this gateway is restarted the clock is rested. so to avoid this problem I would like to use windows 2012 as ntp server.is it possible?

if yes is there any guide that indicates the steps needed for configuration ?

best regards

[Slavik Bialik]

Very easy. Just go to the registry editor (regedit) of your Windows Server 2012, and navigate to:
Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\TimeProviders\NtpServer
You'll find a key named "Enabled" there. Just edit it and set it to 1, and you have a NTP server.
In addition, it is recommended that this NTP server will be also synced from some trusted source, so if it's not synced, sync it to an external NTP server, you can do it like that via command line:
w32tm /config /syncfromflags:manual /manualpeerlist:"0.pool.ntp.org 1.pool.ntp.org 2.pool.ntp.org 3.pool.ntp.org"
Stop-Service w32time
Start-Service w32time

So if this windows server has an access to the Internet, it'll sync from the "pool.ntp.org" NTP servers. If not, instead of that list just put the IP address of an NTP server you're using inside your network.

[Jaime Valencia]

Ensure that external NTP servers are stratum 5 or lower. We recommend that the NTP for the publisher is set to stratum 1, 2, or 3, and that you use only a Linux or IOS NTP source. Windows Time Services as an NTP server is not recommended or supported.

[varungulati]

Hi Jaime,

Can you please point to the document that states CUCM doesn't work with Windows based NTP servers? I couldn't find any reference in the CUCM install guides, the only reference I could find was a general explanation in "IP Application services" Technotes.  

Thanks,

VG

[Jaime Valencia]

That note is in the SRND

[asafgo616]

Hello Jaime,

"Using Windows Time Services as an NTP server is not recommended or supported because Windows Time Services often use Simple Network Time Protocol (SNTP), and Cisco Unified CM cannot successfully synchronize with SNTP."

my customer have Windows NTP server, he doesn't use SNTP in that server, this scenario supported in Cisco?

Thanks,

Asaf

[Jaime Valencia]

No, it won't be supported. Windows NTP are not supported.

[H-Alashi]

Hello varungulati,

you can check this link as a document,

https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-communications-manager-callmanager/215537-network-time-protocol-ntp-on-cucm.html

Best regards,