[ntp:questions] Re: NTP vanished!
Richard B. Gilbert
rgilbert88 at comcast.net
Wed Oct 6 13:49:29 UTC 2004
W. D. wrote:
>At 22:16 10/5/2004, Harlan Stenn, wrote:
>>>>I recommend you use "ntpd -g" (NOT ntpdate)
>>ntpdate is broken and deprecated.
>OK, but how? I've looked at all the docs I can find.
>>>>and use "iburst" on your server
>Great! Will do. Has been taking quite a while
>to synch up. How long does it usually take
>to synch up using iburst? My broadcast signals
>don't go out until the server is synched.
iburst causes the client to send eight request packets with two second
spacing between them at startup. This allows ntpd to fill the
processing pipeline and get a reasonable idea of the round trip delay to
the server and what time it is. This happens in 2*8 = 16 seconds
(longer if you are using a dialup connection). Without it, you need
eight minutes and thirty-two seconds to get to a similar state. ntpd
will need a much longer interval to accurately determine the frequency
error of your clock and begin the process of correcting it. It may
spend eight or ten minutes watching your clock drift before calculating
and applying a preliminary correction. It will then resume watching the
clock drift and will eventually calculate and apply a new, and hopefully
much smaller correction. It might take as much as twenty-four hours to
get your system keeping the best time it is capable of but you should be
in pretty good shape within twenty or thirty minutes.
More information about the questions