[ntp:questions] Using both Server and Peer in ntp.conf

Richard B. gilbert rgilbert88 at comcast.net
Thu Feb 8 19:23:01 UTC 2007


Uwe Klein wrote:
> 
> A question in this context:
> 
> How is an orphaned server that was well
> synced for some time degraded in
> 
> quality and/or stratum
> 
> with/without the local clock
> being used as (additional) server
> 
> over time?
> 
> uwe
> 

The answer is: It depends!   (God I love to be helpful!!!!)

When the server loses its connection to the upstream source, ntpd 
continues to discipline the clock using the last known good frequency 
correction.  It cannot compensate for variations in the environment, of 
which the temperature is the most important.

How many minutes, hours, or days of "holdover" with reasonably correct 
time you may get depends on the quality of the local clock, the 
stability of the temperature, the phase of the moon and the whims of the 
gods!

If you must have the correct time, take precautions such as getting one 
or more hardware reference clocks, redundant internet connections, 
redundant servers, etc.

It might be interesting to try the experiment!  Get a server "well 
synchronized", "orphan" it, and plot the deviation of the clock from the 
correct time versus elapsed time.  (It's possible that you would be 
wasting your time; someone may already have done this.)




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