What Time is It?

One of my Windows 2008R2 servers recently had a hard time syncing time to the default time.windows.com. I know I shouldn't really use it in the first place but what can I say.

I took the time to learn some more about Windows time sync set it up correctly to sync off of multiple servers. The Windows Time Service is controlled by the w32tm executable. Some of the options may work in a regular prompt but for the good commands you will need to run it in an elevated command prompt.

First lets see what is going one by querying the status.

w32tm /query /status
Leap Indicator: 0(no warning)
Stratum: 2 (secondary reference - syncd by (S)NTP)
Precision: -6 (15.625ms per tick)
Root Delay: 0.0559595s
Root Dispersion: 0.0273364s
ReferenceId: 0x808A8DAC (source IP:  128.138.141.172)
Last Successful Sync Time: 5/19/2015 8:05:01 PM
Source: time.nist.gov,0x1
Poll Interval: 8 (256s)

To determine the current source we can query the source.

w32tm /query /source
time.nist.gov,0x1

To compare the current computer to a time server you can use the stripchart function.

w32tm /stripchart /computer:time.nist.gov
Tracking time.nist.gov [128.138.141.172:123].
The current time is 5/19/2015 8:02:40 PM.
20:02:40 d:+00.0599903s o:-00.0166235s  [                           *                           ]
20:02:42 d:+00.0559723s o:-00.0174569s  [                           *                           ]
20:02:44 d:+00.0569959s o:-00.0179584s  [                           *                           ]
20:02:46 d:+00.0569889s o:-00.0174459s  [                           *                           ]

The command I used for this server.

w32tm /config /manualpeerlist:"pool.ntp.org,0x1 time.nist.gov,0x1" /syncfromflags:manual /reliable:yes /update

One item that I have not fully answered is if I should change the 0x1 after each entry to 0x8. 0x1 acts like it is a peer whereas 0x8 is just a client. I suspect that the time servers just ignore the peer information and treat all of the requests as clients but I have not found a definitive answer yet.


Related:
Windows Server w32tm
Windows Time Service at Ntp.org
More Windows Time Service at Ntp.org
How Windows Time Service Works
Windows Time Service Tools and Settings
Explanation of some of the modes of operation
Older Blog Entry from one of the Windows Time Service Authors