From owner-freebsd-stable@FreeBSD.ORG Tue Dec 19 17:51:44 2006 Return-Path: X-Original-To: freebsd-stable@freebsd.org Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 4C4C916A407 for ; Tue, 19 Dec 2006 17:51:44 +0000 (UTC) (envelope-from mike@jellydonut.org) Received: from mail.secureworks.net (mail.secureworks.net [65.114.32.155]) by mx1.FreeBSD.org (Postfix) with SMTP id BE97543CA3 for ; Tue, 19 Dec 2006 17:51:43 +0000 (GMT) (envelope-from mike@jellydonut.org) Received: (qmail 79927 invoked from network); 19 Dec 2006 17:51:42 -0000 Received: from unknown (HELO ?192.168.23.35?) (63.239.86.3) by 0 with SMTP; 19 Dec 2006 17:51:42 -0000 Message-ID: <458826AF.7040908@jellydonut.org> Date: Tue, 19 Dec 2006 12:51:43 -0500 From: Michael Proto User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.8.0.8) Gecko/20061206 Thunderbird/1.5.0.8 Mnenhy/0.7.4.666 MIME-Version: 1.0 To: koitsu@FreeBSD.org References: <20061219124151.GA33385@icarus.home.lan> <20061219132032.GA66632@slackbox.xs4all.nl> <45880BA6.80907@jellydonut.org> <20061219165741.GA40101@icarus.home.lan> In-Reply-To: <20061219165741.GA40101@icarus.home.lan> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: freebsd-stable@freebsd.org Subject: Re: ntpd flipping between PLL and FLL mode X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 19 Dec 2006 17:51:44 -0000 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