Date: Mon, 6 Jul 2009 19:37:01 -0400 From: Louis Mamakos <louie@transsys.com> To: Christian Weisgerber <naddy@mips.inka.de> Cc: freebsd-net@freebsd.org Subject: Re: NTP - default /etc/ntp.conf Message-ID: <20090706233701.GA30824@ringworld.transsys.com> In-Reply-To: <h2t1pr$28me$1@lorvorc.mips.inka.de> References: <20090702084608.GA59311@roberto-al.eurocontrol.fr> <200907020955.aa73037@walton.maths.tcd.ie> <h2t1pr$28me$1@lorvorc.mips.inka.de>
next in thread | previous in thread | raw e-mail | index | archive | help
On Mon, Jul 06, 2009 at 02:30:19PM +0000, Christian Weisgerber wrote: > David Malone <dwmalone@maths.tcd.ie> wrote: > > > (Also, we probably really want people to run in orphan mode rather > > than local clock mode, but we can wait a little longer until orphan > > mode is more commonly deployed, IMHO...) > > I didn't know about orphan mode, so I had to try it right away. > > $ cat /etc/ntp.conf > server 127.127.8.0 mode 14 > fudge 127.127.8.0 time1 0.236 > tos orphan 5 > $ ntpq -p > remote refid st t when poll reach delay offset jitter > ============================================================================== > *GENERIC(0) .DCFa. 0 l 27h 64 0 0.000 -1.255 0.793 > > Shouldn't ntpd have figured out by now that the clock is gone (I > unplugged it yesterday) and have switched into orphan mode? > > -- > Christian "naddy" Weisgerber naddy@mips.inka.de It seems like orphan mode is something that you'd run on an ensemble of local machines to ensure that they continue to be synchronized with each other because that's deemed important for some application need. I don't understand why you'd go to all this trouble on a single host to simulate NTP clock synchronization when in fact the local clock isn't synchronized to anything? If you're concerned about keeping the local clock synchronized to UTC in the event that your NTP process is partitioned from it's external NTP peers, then you don't need to do anything. Once NTP has determined what you're clock's intrinsic frequency error is, the local clock model will contnue to apply this frequency correction even in the absence of external peers providing offset/delay samples. (This is the magic number squirreled away in /var/db/ntp.drift, or wherever it gets put these days.) louie
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20090706233701.GA30824>