[ntp:questions] NTP not seeing servers with a 2-year offset, stand alone configuration

Martin Burnicki martin.burnicki at burnicki.net
Tue Jan 19 20:04:02 UTC 2021


I only came across your message right now.

David Taylor wrote:
> NTP doesn't work as expected when using PPS and GPSD alone, when there
> is a very large offset (2 years) between the host date/time (Raspberry
> Pi) and the GPS date/time.  PPS and GPSD appear to be present (using
> "ppstest" and "ps-e | grep gpsd", and the ntpq display shows the PPS and
> GPS servers but with zero reach.  This is with the Wi-Fi blocked on the
> RPi.
> There is a physical hardware clock on that system, which works correctly
> when the Wi-Fi is unblocked, but sometimes shows a data in February 2019
> with the Wi-Fi blocked.
> The same system works correctly otherwise when unblocked.  Even the
> HWCLOCK can be set and read.
> Does this ring any bells with anyone?

Maybe have a look at this page:

Search that page for "flag1". There should be 2 hits about a constraint
in the initial time offset ("Mode-independent post-processing"), and how
this can be disabled by setting flag1 to 1.

Maybe this helps.



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