[ntp:questions] Time sync on a windows domain

Serge Bets serge.bets at NOSPAM.laposte.invalid
Sat Jun 2 08:20:14 UTC 2007


Hello Jason,

 On Thursday, May 24, 2007 at 14:55:08 +0000, Jason Rabel wrote:

> Windows uses SNTP to fetch time which is more or less a one-shot deal,
> same with ntpdate on *nix. SNTP is just a stripped down version of a
> NTP packet. (You will notice in the internet time tab it says "next
> sync at...") Your clock will be most accurate right after it syncs, but
> will slowly drift without any correction.

Even the oldest win32time sometimes does corrections to the clock
frequency, or something alike it calls "Changing TimeAdjustment from
default increment (to compensate for skew)". The clock can then safely
wait for the next poll/sync without wandering too much.

Ntpdate doesn't do any frequency correction: Between calls, the clock
indeed wanders at the possibly wild crystal frequency. Unless you
calculate the needed mean frequency correction, and set it with
ntptime -f.


Serge.
-- 
Serge point Bets arobase laposte point net




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