Date: Tue, 19 Dec 2006 12:51:43 -0500 From: Michael Proto <mike@jellydonut.org> To: koitsu@FreeBSD.org Cc: freebsd-stable@freebsd.org Subject: Re: ntpd flipping between PLL and FLL mode Message-ID: <458826AF.7040908@jellydonut.org> In-Reply-To: <20061219165741.GA40101@icarus.home.lan> References: <20061219124151.GA33385@icarus.home.lan> <20061219132032.GA66632@slackbox.xs4all.nl> <45880BA6.80907@jellydonut.org> <20061219165741.GA40101@icarus.home.lan>
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Jeremy Chadwick wrote: > On Tue, Dec 19, 2006 at 10:56:22AM -0500, Michael Proto wrote: >> An alternate workaround I've discovered is to use a maxpoll of 9 in >> /etc/ntp.conf: >> >> server rolex.peachnet.edu maxpoll 9 >> >> Since implementing this I haven't seen any of the FLL/PLL flips in my logs. > > How would decreasing the polling time fix this? I do not understand > the semantics/behaviour of NTP very well. > > Taken from the manpage: > > maxpoll maxpoll > These options specify the minimum and maximum poll intervals for > NTP messages, in seconds to the power of two. The maximum poll > interval defaults to 10 (1,024 s), but can be increased by the > maxpoll option to an upper limit of 17 (36.4 h). The minimum > poll interval defaults to 6 (64 s), but can be decreased by the > minpoll option to a lower limit of 4 (16 s). > I made the change some time ago after combing newsgroups for this issue, so my memory is a little hazy, but I seem to remember something about the FLL/PLL switch being right at about 1024s. Check the Tuning section here: http://www.eecis.udel.edu/~ntp/ntpfaq/NTP-s-algo.htm -Proto
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