[ntp:questions] Stick to PPS, even if the prefer server fails

Dave Hart davehart at gmail.com
Sun Mar 22 00:31:52 UTC 2009

On Mar 21, 1:51 pm, "alkope... at googlemail.com"
<alkope... at googlemail.com> wrote:
> If Server A loses the GPS signal, it falls back to LOCAL and begins to
> drift away. In the beginning Server B doesn't care about that and
> stays to the PPS. But later it disconnects PPS and runs on Server A
> again. So both servers drift away. In my opinion Server B should stay
> to the PPS signal. Is there anything I can do about that?

I believe you're limited to options that would keep the prefer peer
surviving NTP's clock selection gauntlet.  I could be mistaken, but I
believe PPS with no prefer peer is intended to stop working.

Dr. Mills' comment "the PPS should still be enabled" confusede me at
first, but I think he's saying assuming your PPS is disciplining the
kernel clock directly, that aspect should continue to keep your local
clock from drifting from its cesium standard during a GPS outage
despite ntpd eventually losing its PPS(1) peer.

Dave Hart

More information about the questions mailing list