ntp config tech note
Joel Jaeggli
joelja at darkwing.uoregon.edu
Thu May 20 21:00:09 UTC 2004
note that ntpdate is actually depreciated. and at some point you'll have
to run ntpd to set the time (with the -q flag) then run it again.
joelja
On Thu, 20 May 2004, Randy Bush wrote:
>
> sorry to take you away from discussing spam with an actual
> tech note, but twice this morning i have hit incidents where
> much needed ntp clients were blown. so, as i was gonna have
> to write it up, i figured i would bore you all with it.
>
> ---
>
> ntp config hint
> 2004.05.20
>
> ntpd will not work if your clock is off my a few minutes.
> it just sits there forever with its finger in its ear. so,
>
> at boot, before you start ntpd, use ntpdate to whack your
> system's time from a friendly low-numbered strat chimer.
>
> do not background ntpdate with -b, because, if it is slow to
> complete, ntpd can't get the port when you try to start it
> next in the boot sequence.
>
> if ntpdate takes a minute and thus adds to your boot time,
> then something is wrong anyway; fix it.
>
> in case your dns resolver is slow, servers are in trouble,
> etc. have an entry for your ntpdate chimer in /etc/hosts.
> yes, i too hate /etc/hosts; but i have been bitten without
> this hack; named is even more fragile than ntpd.
>
> once ntpdate has run, then and only then, start your ntpd.
> and read all the usual advice on configuration, selection
> and solicitation of chimers with which to peer, ...
>
> and then, if having accurate time on this host is critical,
> cron a script which runs `ntpq -c peers` and pipes it to a
> hack which looks to be sure that one of the chimers has a
> splat in front of it. run this script hourly, and scream
> bloody hell via email if it finds problems.
>
> ---
>
> now back to your regular spam discussion. /*
>
> yes, spam is an important issue. but, if your local
> organization, this mailing list, ... gets swamped with
> discussions of spam, then the spammers have won.
>
> you have to compartmentalize it, in your organization and
> in the general net culture. that's why there are
> separate mailing lists for spam, ddos, and other net crap
> with which we have to deal.
>
> that's why we have more than one mailing list in the
> world, to compartmentalize so we can focus.
>
> */
>
> randy
>
--
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Joel Jaeggli Unix Consulting joelja at darkwing.uoregon.edu
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