Date: Thu, 2 Jul 2009 11:29:24 +0200 From: John Hay <jhay@meraka.org.za> To: David Malone <dwmalone@maths.tcd.ie> Cc: freebsd-net@freebsd.org, Edwin Groothuis <edwin@freebsd.org> Subject: Re: NTP - default /etc/ntp.conf Message-ID: <20090702092924.GA52735@zibbi.meraka.csir.co.za> In-Reply-To: <200907020955.aa73037@walton.maths.tcd.ie> References: <20090702084608.GA59311@roberto-al.eurocontrol.fr> <200907020955.aa73037@walton.maths.tcd.ie>
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On Thu, Jul 02, 2009 at 09:55:44AM +0100, David Malone wrote: > > > We are supposed to contact the people running the pool and ask for > > > a freebsd.pool.ntp.org subdomain. > > > That's a good idea. > > OK - should I contact the pool guys and ask for freebsd.pool.org? > > > > Second, we shouldn't have the local clock configured by default. > > > Why? > > When Redhat did this, it caused a variety of niggles and compaints > in the ntp community. The recent thread in comp.protocols.time.ntp > gives one example where the local clock came under suspicion for > causing various problems. It also interfers with people using real > local clocks, where the system clock is controled by something other > than NTP, and you just want NTP to distribute the time. > > > > 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. > > (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 agree with what David said. Maybe just in addition, a client machine (one that do not supply time to anyone), is not really worse off if its ntpd daemon is not synchronised because it could not get to valid ntp servers, so here you do not gain anything by adding a fake local clock. You might just cause confusion because it will look like it is synchronised where it is actually not. In the ntp server case you want to be really carefull with using the fake local clock. It can cause a lot of problems. My feeling is that the fake local clock should not even be commented out in the default ntp.conf file. It should totally removed. John -- John Hay -- jhay@meraka.csir.co.za / jhay@FreeBSD.org
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