[ntp:questions] ntpdate

RICCARDO castellani.riccardo at tiscali.it
Thu Mar 29 15:18:10 UTC 2007


On 28 Mar, 20:23, Eric <nospam... at jensenresearch.com> wrote:
> Well, using ntpdate will always "step" your PC clock, so you can count on it jerking
> forward and back at each chron interval.  So I'm not sure how it would help to always
> use the same server, it will still hop around even from one server.  And, ntpdate I
> believe has been "deprecated" and is no longer being enhanced or supported.
>
> What you really want is somehow to reach out to several servers, get an approximation
> of the correct time by consensus, then slowly steer the PC clock to match it.  No
> steps, no dependency on a particular server.  
>
> This is what the reference implementation of NTP does.  It's called NTPD.  I'd give
> that a try.
>
> - Eric
>
> On 28 Mar 2007 02:50:11 -0700, "RICCARDO" <castellani.ricca... at tiscali.it> wrote for
> the entire planet to see:
>
>
>
> >I use ntpdate command in crond to synchronize local clock of my Linux
> >servers.
> >I run ntpdate -B -s ntp1.ien.it ntp2.ien.it
>
> >1- NTP algorithm will choose best time, so is't possible client
> >retrieves time from ntp1 server or ntp2 ? Can you confirm me this
> >behaviour ?
> >2- Does it exist way to retrieve time ALWAYS from same server (for
> >example ntp1) and only if it is not available gets time from second
> >server (ntp2) ?- Nascondi testo tra virgolette -
>
> - Mostra testo tra virgolette -

I think time offset is very little at every each cron interval; "-B"
option uses "adjtime" system call which is more soft function to
adjust time. (it slowly steers pc clock)
What do you think ?
I thought to use ntpdate so in this way I have no installed service,
CPU load is more free and thare are no attacks risk from other
machines.




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