[ntp:questions] Re: Linux NTP Polling

Brad Knowles brad at stop.mail-abuse.org
Wed May 11 10:35:30 UTC 2005


At 7:55 PM +1000 2005-05-11, Geoff wrote:

>  Actually the change in time is significant, by years, not seconds.

	If your time server suddenly jumps years, then all the clients 
are going to exit.  The hard limit is one thousand seconds, not 
milliseconds, days, months, or any other unit of time -- 1000 
seconds.  If you suddenly exceed that limit after you've gone through 
the startup phase, then all NTP clients should exit as soon as they 
detect that change.

>                                                                      How can
>  I test it is actually re-syncing if the max timeout is 1000 seconds (ok,
>  1000 secs is ok but is it Secs or Msecs?)

	It's not a timeout -- it is an absolute maximum difference 
between client and server, and the value is 1000 seconds.

>                                             I can change the time by a few
>  mins to check if you think that is the better option, all I want to know is
>  if it is re-syncing.  I waited 1/2 hour to an hour.

	Generally speaking, you watch the logs, or you watch the output 
from "ntpq -p".  If you use this command, you simply run it every 
minute or so and watch the values as they change.  You're looking for 
the amount that your server thinks it is offset from the upstream 
time server, which is the next-to-last column in the output from this 
command.

>  No, haven't checked the system log.  In fact to sound dumb, how do I do
>  that?  This version of Linux is very watered down as it is on a switch.

	You should be able to check the log the same way you would any 
other Linux machine.  If not, then you would need to contact your 
vendor for details.

-- 
Brad Knowles, <brad at stop.mail-abuse.org>

"Those who would give up essential Liberty, to purchase a little
temporary Safety, deserve neither Liberty nor Safety."

     -- Benjamin Franklin (1706-1790), reply of the Pennsylvania
     Assembly to the Governor, November 11, 1755

   SAGE member since 1995.  See <http://www.sage.org/> for more info.



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