[ntp:questions] Client doesn't drop failed source

Michael Moroney moroney at world.std.spaamtrap.com
Mon Jan 11 22:12:57 UTC 2010

Can anyone point me to anything similar to "How to explain NTP to Project
Managers" esp. explaining how a preferred clock server is included even
though the LAN cable is known to be dangling from the rack.  Most of which
I find with Google is too technical.  This is confusing to me as well,
with the algorithm tracking round trip times, compensating for offsets, 
drift, jitters etc., plus this is all new to me.

What I was asked to do is pretty much as follows: Track Clocks A and/or B
as long as either are available, otherwise track Clocks C and/or D.

All 4 clocks are GPS clocks (stratum 1) and clocks C and D belong to 
another group and are supposed to be "backup" while A and B are "our"

Manager expects that if the LAN cable to A is pulled, A will be dropped 
and system will synch to B and vice versa.  The "disconnect antenna" test
worked perfectly since the clocks changed their stratum to 16 and the
system dropped them as a source on the next poll.  I do understand that in
actuality all the available Stratum 1 Clocks will be used, and I understand
that the actual NTP client and clocks don't care who "owns" them.

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