From owner-freebsd-hackers@freebsd.org Tue Oct 9 14:06:37 2018 Return-Path: Delivered-To: freebsd-hackers@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id BDB7910CFE97 for ; Tue, 9 Oct 2018 14:06:37 +0000 (UTC) (envelope-from ian@freebsd.org) Received: from outbound2r.ore.mailhop.org (outbound2r.ore.mailhop.org [54.200.129.228]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 4B1AC8A898 for ; Tue, 9 Oct 2018 14:06:37 +0000 (UTC) (envelope-from ian@freebsd.org) X-MHO-RoutePath: aGlwcGll X-MHO-User: 804053b6-cbcc-11e8-a70c-1d534e3451d5 X-Report-Abuse-To: https://support.duocircle.com/support/solutions/articles/5000540958-duocircle-standard-smtp-abuse-information X-Originating-IP: 67.177.211.60 X-Mail-Handler: DuoCircle Outbound SMTP Received: from ilsoft.org (unknown [67.177.211.60]) by outbound2.ore.mailhop.org (Halon) with ESMTPSA id 804053b6-cbcc-11e8-a70c-1d534e3451d5; Tue, 09 Oct 2018 14:06:25 +0000 (UTC) Received: from rev (rev [172.22.42.240]) by ilsoft.org (8.15.2/8.15.2) with ESMTP id w99E6Lwn012894; Tue, 9 Oct 2018 08:06:21 -0600 (MDT) (envelope-from ian@freebsd.org) Message-ID: <1539093981.72469.30.camel@freebsd.org> Subject: Re: ntpd strange problem From: Ian Lepore To: Wojciech Puchar , Peter Jeremy Cc: freebsd-hackers@freebsd.org Date: Tue, 09 Oct 2018 08:06:21 -0600 In-Reply-To: References: <20181005061829.GG21091@server.rulingia.com> <1538855151.14264.54.camel@freebsd.org> <20181009052924.GJ21091@server.rulingia.com> Content-Type: text/plain; charset="ISO-8859-1" X-Mailer: Evolution 3.18.5.1 FreeBSD GNOME Team Port Mime-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.27 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 09 Oct 2018 14:06:37 -0000 On Tue, 2018-10-09 at 08:42 +0200, Wojciech Puchar wrote: > > > > > > > > Strange but today (4 days after i restarted ntpd) it seems to be > > > in sync > > A couple of suggestions: > > * (especially if you have an ADSL link): The NTP protocol assumes > > that > > the path between the client and server are have symmetric > > timing.  In > i have gigabit connectivity with low and stable delays. so it's not > this. > > > > > my experience, bulk uploads or downloads can cause significant path > > delay asymmetries, which can confuse ntpd. > > * You only have a single server and are therefore dependent on the > > trustworthiness of that server.  A few more servers could be > > useful. > this server is quite (actually excellently) stable and i trust it. When I asked for various outputs, I meant "when the unsync problem is happening"; those outputs are uninteresting when everything is working right. You should remove the config for the "local" clock from your ntp.conf. Configuring a bogus local clock is NEVER the right thing to do, and it's even worse to configure it at a high stratum number. -- Ian