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Date:      Thu, 5 Mar 2020 15:23:44 +0000
From:      Bob Bishop <rb@gid.co.uk>
To:        Peter Jeremy <peter@rulingia.com>
Cc:        Dewayne Geraghty <dewaynegeraghty@gmail.com>, freebsd-stable stable <freebsd-stable@freebsd.org>
Subject:   Re: ntp problems stratum 2 to 14?
Message-ID:  <53A0BB94-6D6B-472B-9BCF-9B49EDFF7593@gid.co.uk>
In-Reply-To: <20200305063332.GC42815@server.rulingia.com>
References:  <CAGnMC6q2V6tfA%2BbkSXVgTq1poaLgrkv4Hd=R6fNBAZASUZPu4A@mail.gmail.com> <20200226194329.GA85186@server.rulingia.com> <CAGnMC6o9ruSJQS14McEd2Z1ib58M=O6yENuUi6F00WcnGTy37Q@mail.gmail.com> <20200305063332.GC42815@server.rulingia.com>

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Hi,

> On 5 Mar 2020, at 06:33, Peter Jeremy <peter@rulingia.com> wrote:
>=20
> Hi Dewayne,
>=20
> Sorry for the delay.  Unfortunately, I can't really suggest anything -
> it's not clear to me why ntpd would prefer a stratum 14 clock over a
> stratum 2 clock.  Have you tried looking through the debugging hints
> page (https://www.eecis.udel.edu/~mills/ntp/html/debug.html)?
>=20
> I haven't seen that problem but I don't use the local clock.
>=20
> During startup, it would not seem unreasonable for the local clock to
> become valid first because it will have a lower jitter.  But ntpd
> should switch to the stratum 2 clock and stay with in as the better
> time source.  One problem is that if ntpd decides to switch away from
> the clock for any reason (eg a burst of jitter), it may get stuck on
> the local clock as it drifts further from "real" time.

Yes. I=E2=80=99ve had exactly that happen with a stratum 1 (GPS) server =
with only local as fallback. The GPS signal dropped for a while and the =
box drifted off sufficiently that it wouldn=E2=80=99t reacquire the =
accurate clock.

The solution is to add a few pool (or whatever) servers into the config =
- you can still =E2=80=98prefer=E2=80=99 a local server but it ensures =
the box won=E2=80=99t drift off into the weeds.

> --
> Peter Jeremy

--
Bob Bishop
rb@gid.co.uk





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