[ntp:questions] Win7: ntpd adjusting time backwards

Jeroen Mostert jmostert at xs4all.nl
Sat Dec 8 21:18:14 UTC 2012

On 2012-12-08 22:03, David Woolley wrote:
> If you suffer from temporary severe asymmetric delays, you can use the huff and
> puff tinker option to try and compensate.
Given that the adjustments come about every hour, and the machine is not doing 
anything particularly interesting with the network, *and* I've seen this 
behavior on other Win7-machines configured to use the NTP pool servers (with 
radically different network setup/use) I doubt that would do the trick. But I'll 
keep it in mind.

For now I've tried setting NTPD_USE_INTERP_DANGEROUS, because 1) it has 
DANGEROUS in the name, FOR SCIENCE! and 2) it's reported that the interpolation 
may actually work again on Windows 7 machines, sometimes (it didn't work well on 
Vista, which is why ntpd started using the clock directly).

Though it's really too early to tell, it's interesting that the offset has kept 
to <40 ms since the last restart 2 hours ago and no adjustment to the system 
time has been logged, so this may be a keeper.


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