On Wed, Nov 29, 2023 at 08:49:55AM +0100, Otto Moerbeek wrote:
> On Tue, Nov 28, 2023 at 04:19:07PM +0100, Paul de Weerd wrote:
>
> > Hi all,
> >
> > I have a few APU's I'm using to experiment with some stuff. I found all
> > of them unable to sync with NTP because they don't have IPv4
> > connectivity to the outside world.
> >
> > Digging a bit deeper, it turns out that v6 is only configured after
> > ntpd is started. This means the constraints cannot be reached (ntpd
> > logs "constraints configured but none available"). Even if v6 becomes
> > available (shortly after) ntpd is started, ntpd still refuses to try
> > to connect to the constraints over IPv6.
> >
> > Simply restarting ntpd when an IPv6 address is configured makes
> > everything go again: the constraint servers can be reached, so those
> > are checked, and then the regular NTP servers also work fine.
> >
> > Address configuration is dynamic:
> >
> > --- cat /etc/hostname.em0 --------------------------------------------
> > up
> > inet autoconf
> > inet6 autoconf
> > ----------------------------------------------------------------------
> >
> > I have confirmed the behaviour by removing all config from the
> > interface, stopping ntpd and then bringing up a v4 address (ifconfig
> > em0 inet autoconf), starting ntpd and bringing up a v6 address
> > (ifconfig em0 inet6 autoconf). ntpd never connects to the constraint
> > servers, despite having a v6 address (and the constraint servers have
> > AAAA records, obviously). Again, restarting ntpd when a v6 address is
> > configured gets things going: constraint servers are reached just
> > fine, and time is adjusted according to NTP.
> >
> > Paul 'WEiRD' de Weerd
>
> I'll see if I can find the root cuase of this.
>
> -Otto
>
So I tried a couple of configs--all with a v6 address coming up late--
with both no v4 at all and v4 but not working, but in all cases
(though it may take a while) the contrainst *did* use v6 addresses,
both for the hardcoded case and retrieved via DNS case.
So I like to see your config and also -vv log files to figure out
what's different in your setup.
-Otto
