[ntp:questions] Problem with good synchronization.

Marcin Okraszewszki okrasz_news at o2.pl
Fri Oct 15 08:48:26 UTC 2004

I need to synchronize computers' clocks very tightly. I mean clocks
offset shouldn't exceed 50ms. All computers are in the same LAN, so in
fact network traversal time isn't very big. But with default settings I
find that offset even goes to 700ms, and from time to time there are
some step clock changes that are highly undesirable (at least with
amount of 500ms).

I tried to set minpoll 4 and maxpoll 5 turned step 0 (to avoid sudden
time changes) The results are as fallows: absolute value of offset has
reduced to average 70ms with standard deviation 90ms and maximum 350ms.
This is not good enough. What is even worse, suddenly the time offset to
server was 60s (not ms)!! And it happened in all clients at the same
time, which for me means that something happened with the time on the
server, but there is nothing about it in the system log.

Is there any way to improve this situation?

The ntp server is running Windows 2000 (ntpd 4.1.72) and clients are
Linuxes (ntpd 4.1.1). To measure the offset I use ntptrace. The Windows
is not synchronized to any other source.

Thanks for help.
Marcin Okraszewski

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