DCs, time event 142, w32time, and group policy

Over a year ago, we applied a fix related to this on our domain controllers because of intermittently reported client problems. This fix was the most significant finding out of Microsoft AD RAP as a service engagement that we had.

Turns out that down in the deep details of the time settings there’s a lot that can cause problems. And Microsoft deployed poor values for many of those settings for prior OSes, some of which got encoded in the default group policy values. We turned on those group policy settings back when the values were really bad, and of course, those bad values were still in place because nothing will automatically change an existing GPO setting.

 

Here’s a table summarizing the craziness:

  2008R2 Admx Defaults 2008 / 2008R2 DC Default* 2008 / 2008R2 Member Defaults 2003 Adm Defaults 2003 DC Defaults
FrequencyCorrectRate 4 4 4 4 4
HoldPeriod 5 5 5 5 5
LargePhaseOffset 50000000 50000000 50000000 128000 50000000
MaxAllowedPhaseOffset 300 300 300 300 300
MaxNegPhaseCorrection 172800 172800 4294967295 54000 4294967295
MaxPosPhaseCorrection 172800 172800 4294967295 54000 4294967295
PhaseCorrectRate 1 7 1 1 7
PollAdjustFactor 5 5 5 5 5
SpikeWatchPeriod 900 900 900 90 900
UpdateInterval 100 100 30000 30000 100
AnnounceFlags 10 10 10 10 10
EventLogFlags 2 2 2 2 3
LocalClockDispersion 10 10 10 10 10
MaxPollInterval 10 10 15 15 6
MinPollInterval 6 6 10 10 10

* These are the settings you want on you DCs as they are the OS defaults for a DC

 

On your DCs, you want to apply what’s in the column labeled “2008/2008R2 DC Default*”. To correct our problem, I turned off all the GPO time settings. Then I turned them back on. Then I fixed the only setting whose (GPO) default value doesn’t match the OS default value for a DC (PhaseCorrectRate).

 

This fixed all of the time events being raised in our domain.

 

YMMV, but I expect this will likely help quite a few folks.

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