[ntp:questions] Does NTP cause an abrupt/sudden change in an orphan's system time?

Harlan Stenn stenn at ntp.org
Wed Aug 8 11:03:04 UTC 2012


Arpith Nayak writes:
> I have a server that is in the orphan mode i.e. it was not connected to the
> internet (and thus the various public NTP servers) when I booted it up. Now
> if I install ntpd oin this server and run it, will the first instance of
> ntpd cause a sudden change in the system time as well as timestamps or does
> NTP cause a slow gradual change so that it syncs up with the public server
> over a period of time?

If you don't override this in the ntp.conf file, it will "step" any
change of greater than 128ms as soon as it knows the time.

If you override this in the ntp.conf file (or via a startup option) it
will slew the time gradually, but realize it may take a *very* long time
to get the clock right.  This type of change is applied at 500ppm, so a
change of 1 second will be applied over 2000 seconds.

H


More information about the questions mailing list