topic Re: NTP frequency ? in Operating System - Linux

NTP frequency ?

Debbie Fleith — Mon, 09 Oct 2006 10:54:15 GMT

How often does ntpd poll a time server to check if updates are needed?

Re: NTP frequency ?

Ivan Ferreira — Mon, 09 Oct 2006 11:09:23 GMT

You can identify that information from the ntpq -pn command, the poll column. You can use also the minpoll and maxpoll configuration options.

Re: NTP frequency ?

Debbie Fleith — Mon, 09 Oct 2006 11:17:02 GMT

What does the number in the poll column refere to? Mine says 64, is that 64 seconds/minutes or ?

Re: NTP frequency ?

Al Licause — Mon, 09 Oct 2006 11:56:52 GMT

My notes say the poll interval displayed from ntpq is in seconds. The man page doesn't give that level of detail.....unfortunate.

Re: NTP frequency ?

Ivan Ferreira — Mon, 09 Oct 2006 13:49:22 GMT

minpoll #
maxpoll #

Specify the minimum and maximum polling interval for NTP messages, in seconds to the power of two. The default range is 6 (64 seconds) to 10(1024 seconds). The allowable range is 4 (16 seconds) to 17 (36.4 h) inclusive.

So, what you see is in the output of ntpq is seconds.

Re: NTP frequency ?

rick jones — Mon, 09 Oct 2006 19:46:56 GMT

The limits to poll frequency have already been stated - as NTP decides that things are "stable" it will increase the interval between queries of the time servers (one should always have at least two time servers configured...)

If the poll frequency remains high (ie a small interval between queries) it suggests that either NTP does not yet think things are sufficiently stable, or it has decided that things cannot become sufficiently stable to allow a longer polling interval.

Re: NTP frequency ?

Steven E. Protter — Sun, 15 Oct 2006 02:53:18 GMT

Shalom,

The default in ntp.conf has always worked for me.

SEP

Re: NTP frequency ?

timmy2006 — Wed, 08 Nov 2006 01:05:16 GMT

ntpd can somehow crash or failed to start and almost always you will notice it when log dates will differ with other machines.
i prefer to use ntpdate 'ip' in cron sheduled to start every 15'.