From owner-freebsd-net@FreeBSD.ORG Thu Jul 2 18:21:13 2009 Return-Path: Delivered-To: freebsd-net@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 707B41065678; Thu, 2 Jul 2009 18:21:13 +0000 (UTC) (envelope-from brde@optusnet.com.au) Received: from mail03.syd.optusnet.com.au (mail03.syd.optusnet.com.au [211.29.132.184]) by mx1.freebsd.org (Postfix) with ESMTP id 0BF438FC1C; Thu, 2 Jul 2009 18:21:12 +0000 (UTC) (envelope-from brde@optusnet.com.au) Received: from c122-106-161-96.carlnfd1.nsw.optusnet.com.au (c122-106-161-96.carlnfd1.nsw.optusnet.com.au [122.106.161.96]) by mail03.syd.optusnet.com.au (8.13.1/8.13.1) with ESMTP id n62IL1rC011262 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Fri, 3 Jul 2009 04:21:04 +1000 Date: Fri, 3 Jul 2009 04:21:02 +1000 (EST) From: Bruce Evans X-X-Sender: bde@delplex.bde.org To: David Malone In-Reply-To: <200907020955.aa73037@walton.maths.tcd.ie> Message-ID: <20090703035833.E40558@delplex.bde.org> References: <200907020955.aa73037@walton.maths.tcd.ie> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: Edwin Groothuis , freebsd-net@FreeBSD.org Subject: Re: NTP - default /etc/ntp.conf X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 02 Jul 2009 18:21:13 -0000 On Thu, 2 Jul 2009, David Malone wrote: >>> The local clock should only be configured on a single server in a >>> NTP domain that might be disconnected from the rest of the tree. >>> Since the default config is a client config, it doesn't make sense >>> to have the local clock configured. Even if it was a server config, >>> it still wouldn't make sense, because it is only useful if a single >>> server has it configured. > >> I do not see the point in removing it, it helps to keep the ntpd daemon >> running if for some reason it loses the "real" ntp servers. > > It's definitely a misconfiguration to ship it by default. If you > have many clients all with a local clock configured, then, when > disconnected, they all just follow themselves rather than following > the clock on a server. If you have it configured on several servers > you end up with some clients following each of the servers, but > they won't all stay together unless you're lucky. For this use of > the local clock, you only want one local clock per island that might > become disconnected. This is handled by having different local clocks in different strata. I only use 2 such strata -- 1 for server and another for all clients. But this is not so easy to set up as a default. ref8 FreeBSD cluster machines have the new ntp.conf, so they have the local clock with the same stratum and this misconfiguration is getting some official testing :-). It is probably actually unofficial, due mergemaster blowing away the old primitive ntp.conf which is still used on other FreeBSD cluster machines. This seems to break the server config generally -- ntptrace on ref8* hangs after localhost while ntptrace on ref7-amd64 hangs after hub. Bruce