[ntp:questions] Test internal clock

David Woolley david at ex.djwhome.demon.co.uk.invalid
Thu Mar 19 22:27:49 UTC 2009

Rob wrote:

> When somebody asks a question about a Windows system, where a native
> NTP implementation is available that can be debugged with a simple
> commandline program (w32tm), the response to any question invariably
> is to "install ntpd".

One key factor is that Microsoft never post to this newsgroup.  Only 
they really know how w32time works.  They do not release source code and 
the Technet article is not sufficient without access to source code.

However, prior to Windows 2003, w32time definitely didn't implement NTP, 
and, at least in the original implementations, its SNTP implementation 
was broken.  Later versions are broken out of the box, but can be 
configured to comply.

The Windows 2003 version does seem to have some NTP like capabilities, 
but it is not at all clear that it is internally fully compliant, even 
when configured.  Also, to produce anything that stands a chance of 
being compliant, one needs to change a large number of its registry 

The reference implementation interpolates clock ticks, but w32time doesn't.

However, I'm sure that on many occasions people have been given w32time 
as an option, with the caveat that it is only suitable for relatively 
crude time setting (several seconds for naive users).

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