[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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