NTP time sync with Windows 2003

It is well known problem that Communication Manager cannot synchronize time with Windows 2003 Server machines over NTP. Here’s the workaround recommended by Avaya Tier 3 support engineers:

The NTP client on the S8X00 server is rejecting the NTP server because it considers it as a not reliable source clock. The NTP server reports the ‘root dispersion’ value with 10 seconds and this is considered too high. This is a Windows 2003 server issue and it is not an S8X00 problem. Below is what you can do on the Windows server.

Change the LocalClockDispersion value in the Windows 2003 server registry, from the default value 10 to 0, the registry value is:

HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesW32TimeConfigLocalClockDispersion

This can be done from the command line:

w32tm /config /LocalClockDispersion:0

Restart the Windows Time service, this can be done from the services application in windows or from the command line:

net stop w32time && net start w32time

I hope this helps.

It helped indeed. I haven’t checked this with Windows 2008 but if the symptoms are alike, the solution above may be valid.

One Comment

  • Ramon says:

    Hi,

    Should this follow the same logic for windows 2008 and 2012 servers?
    I’m having a problem that the server synchronizes the first time after it loses the synchronization.

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