[ntp:questions] flipping between stratum 1 clocks regularily

mmoore0011 at hotmail.com mmoore0011 at hotmail.com
Tue Feb 19 16:58:27 UTC 2008


I've recently been provided with 4 "highly accurate" ntp servers that
are using GPS as their primary synchronization source.  Well, 2 of the
hosts are using GPS (stratum 1) and the other two are syncing to those
(stratum 2).  I've been going around configuring all 4 hosts in my
ntp.conf and am starting to notice that my machines are flipping back
and forth between the two stratum 1s.  I don't think this is

Some of the documentation from the clock vendors suggests that their
clocks are "so accurate" that ntp has a hard time determining which is
more so and this affect can occur.  I was thinking of dropping one of
the ST1 clocks from the config and going with 1 ST1 and 2 ST2s....
that seems more stable in a test.  I wanted to see if anyone else has
dealt with something similar and how you fixed it.


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