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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[-- Attachment #1 --] Hi, > On 5 Mar 2020, at 06:33, Peter Jeremy <peter@rulingia.com> wrote: > > Hi Dewayne, > > 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)? > > I haven't seen that problem but I don't use the local clock. > > 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’ve 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’t reacquire the accurate clock. The solution is to add a few pool (or whatever) servers into the config - you can still ‘prefer’ a local server but it ensures the box won’t drift off into the weeds. > -- > Peter Jeremy -- Bob Bishop rb@gid.co.uk [-- Attachment #2 --] -----BEGIN PGP SIGNATURE----- iF0EARECAB0WIQR+a6Wh87I/iYwcbE+8xpPppLfFvwUCXmEZgAAKCRC8xpPppLfF v9kBAKCAxe9gUzpB6ljW7t0CaWXIJAtcxACfXQUcYYCQQRJbifZY65ZISBI8vsk= =mCf7 -----END PGP SIGNATURE-----home | help
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