Date: Tue, 14 Jul 2015 10:47:59 -0400 From: Paul Mather <paul@gromit.dlib.vt.edu> To: krad <kraduk@gmail.com> Cc: freebsd-stable <freebsd-stable@freebsd.org> Subject: Re: Circular dependency between local_unbound and ntpd? Message-ID: <E6BF2A3D-01CA-4AE5-AB3D-883ADE3DF26C@gromit.dlib.vt.edu> In-Reply-To: <CALfReye4Byhv0dX%2B2JVm=CEuAPnDitYOwgBFm_071Qwg_jvP_g@mail.gmail.com> References: <EDD17B95-0EA7-4C97-836D-7707416C0F07@gromit.dlib.vt.edu> <CALfReye4Byhv0dX%2B2JVm=CEuAPnDitYOwgBFm_071Qwg_jvP_g@mail.gmail.com>
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On Jul 14, 2015, at 10:33 AM, krad <kraduk@gmail.com> wrote: >=20 > As >=20 > $ grep REQUIRE /etc/rc.d/ntpd > # REQUIRE: DAEMON ntpdate FILESYSTEMS devfs >=20 >=20 > You could set something similar to the following in the rc.conf >=20 > ntpdate_hosts=3D"a.b.c.d w.x.y.z" > ntpdate_enable=3Dyes Thanks for that suggestion. I assume the "a.b.c.d w.x.y.z" are IP = addresses, not hostnames, otherwise we'd have the same problem. The /etc/rc.d/ntpdate startup script has a "REQUIRE: NETWORKING ..." and = /etc/rc.d/local_unbound has a "BEFORE: NETWORKING" in it, meaning it = will be running before ntpdate runs. That means DNS resolution will = require an accurate clock and, I assume, mean that ntpdate will require = IP addresses, too? So, it still comes down to this: do I need to know the IP address of an = NTP server to be able to use local_unbound safely with NTP? Cheers, Paul. >=20 >=20 >=20 >=20 > On 14 July 2015 at 14:43, Paul Mather <paul@gromit.dlib.vt.edu = <mailto:paul@gromit.dlib.vt.edu>> wrote: > I believe I ran afoul of a circular dependency between local_unbound = and ntpd on my 10.2-PRERELEASE system. I use a stock /etc/ntp.conf and = use ntpd_sync_on_start=3D"YES". >=20 > Last night, a BIOS settings reset cause my CMOS clock to go WAY out of = synch for the first time. No problem, I thought: NTP will correct it at = boot. >=20 > Wrong! >=20 > When my system booted, the time was not corrected. Also, DNS = resolution was not working. I figured out it was because local_unbound = relies on an accurately set clock, but the clock could not be set = accurately because my stock ntp.conf requires working DNS resolution to = reach the NTP servers. >=20 > That sounds like a potential circular dependency to me. >=20 > My workaround at the time was to look up 0.freebsd.pool.ntp.org = <http://0.freebsd.pool.ntp.org/>; on another system; stop ntpd; then do a = ntpdate using the IP addresses to set the clock. Once the clock was set = accurately, things were all hunky dory. >=20 > Does anyone have any suggestion for an automatic way around this? I = guess one way would be to put the IP address of an NTP server into my = ntp.conf file, so at least one would be reachable without needing a = working DNS? >=20 > My main concern is for those systems like my Raspberry Pi and = Beaglebone Black that don't have a battery-backed clock. I currently = don't use local_unbound on those, but it seems like I'd encounter this = problem routinely if I did. >=20 > Cheers, >=20 > Paul. > _______________________________________________ > freebsd-stable@freebsd.org <mailto:freebsd-stable@freebsd.org> mailing = list > http://lists.freebsd.org/mailman/listinfo/freebsd-stable = <http://lists.freebsd.org/mailman/listinfo/freebsd-stable>; > To unsubscribe, send any mail to = "freebsd-stable-unsubscribe@freebsd.org = <mailto:freebsd-stable-unsubscribe@freebsd.org>" >=20
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