Re: [gpsd-users] Help with extracting time information from GPS to NTPD

[Dave Hart]

On Tue, Nov 8, 2011 at 10:21, Jordan <address@hidden> wrote:
> However I can't quite figure out how to get ntpd to pull the information
> from gpsd. I've modified my /etc/ntp.conf to:
>
> Code:
>
> server 127.127.28.0 minpoll 4 maxpoll 4
> fudge 127.127.28.0 refid GPS
>
> restrict 127.0.0.1
> restrict 10.1.1.0 mask 255.255.255.0 nomodify notrap
>
> where 127.127.28.0 is supposed to be the IP to access the GPS information. I
> can ping that IP successfully. However when I try to access the server using
> ntpq -p, it says 'No association ID's returned'.

My bet is your ntpd was compiled with options that left out the SHM
refclock driver (or all refclocks).  There should be a message from
ntpd in syslog hinting as much.

> If I stop NTPD and run 'ntpdate 127.127.28.0' it says there were no suitable
> synchronization servers found.

That's not really an IP address.  127.*.*.* are all localhost, which
is why you can ping it.  ntpd special-cases 127.127.d.u to refer to
reference clock driver number d, unit number u.  Only within ntpd do
those IPs refer to reference clocks.

Cheers,
Dave Hart