[ntp:questions] NTP servers redundancy

Rob nomail at example.com
Tue Jan 19 16:57:37 UTC 2010

Richard B. Gilbert <rgilbert88 at comcast.net> wrote:
> The fundamental problem with two servers is this: which one do you 
> believe when the two differ?  You know that at least one of the two must 
> be wrong but it's impossible to determine WHICH one!

This is not relevant when the two servers return the same time within
the margin that one considers acceptable.

So when you have two servers that each are synchronized to the same
GPS PPS clock, there should be no problem.  They return the same time
or no response at all (when down) and the clients will lock on either
of them without problem.

When a server returns the wrong time and still says it is synchronized,
there is a software bug.  This you aren't going to solve with as many
servers as you like (all setup the same way).  Then you would need to
run many servers with different software versions, different OS, different
hardware, etc.

Probably more trouble than the problem is worth.

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