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

Dave Hart davehart at gmail.com
Mon Mar 23 04:00:14 UTC 2009

Dr. Mills,

Thank you for your confirmation.  The original poster should be
satisfied, assuming their kernel time is being disciplined directly by
their cesium standard.  If they are unable to use the kernel
discipline for some reason, could they tinker _max_disp (I don't know)
to keep the upstream server with GPS surviving longer?  If there is no
maximum dispersion tinker, "tinker dispersion 5" on the upstream
server with GPS should similarly delay the inevitable.  (The default
is 15, units part per million)

Dave Hart

On Mar 23, 3:22 am, mi... at udel.edu (David Mills) wrote:
> Dave,
> Once the kernel PPS is lit, it will stay lit even if the daemon loses
> the prefered soure or even dies.This is the intended behavior, which I
> confirmed just now. Veriy that  ntptime shows PPSTIME lit after the
> daemon loses the prefer peer or is stopped.
> By the way, with just a remote peer and PPS, the intersection algorithm
> is quite picky if the remote peer strays a bit. Use tinker mindisp to
> something higher, like .05 s.

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