[LinuxPPS] chrony with LinuxPPS and gpsd

[Miroslav Lichvar]

On Tue, Jun 22, 2010 at 02:22:05PM +0200, Remco dB wrote:
> Miroslav,
> 
> I want to test it on a system which is fed by a PPS signal, locked to UTC 
> epochs. So, in ntpd terms: I only need an external (internet) reference and 
> driver 22 (127.127.22.0).
> 
> Therefore I do not need the gpsd part. 
> 
> How do I need to config chrony in that case?

Replace the SHM refclock with a server directive and remove the lock
from PPS. Like this:

server 0.pool.ntp.org
refclock PPS /dev/pps0

If it's a local NTP server, you might want to add minpoll 4 maxpoll 4
or similar to the server specification.

> Afterwards, is chronyd 'ntpdc-able' ? I.e. are ntpdc queries like
> ntpdc -c kern <host> possible?

The protocols used by ntpq and ntpdc are not supported, chrony has its
own protocol running on UDP port 323. It's used by the chronyc
utility. By default, only connections from localhost are allowed, use
cmdallow directive in chrony.conf to allow access from other IP
addresses or networks as needed.

-- 
Miroslav Lichvar