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

unruh unruh at wormhole.physics.ubc.ca
Sat Jan 9 04:18:16 UTC 2010

On 2010-01-09, Michael Moroney <moroney at world.std.spaamtrap.com> wrote:
> David Woolley <david at ex.djwhome.demon.invalid> writes:
>>Michael Moroney wrote:
>>> that synchronizes with the four clocks, and ntpq> peers shows one of the
>>> primaries with a "*" in the first column meaning it was synchronized to as
>>> time source, the other 3 show "+" as expected, meaning they are usable
>>> sources.  We disconnect the antenna of the selected clock.  As expected
>>* and + mean they are used, not just that they are usable.  The time 
>>used to discipline the clock is a weighted average of all of them.
> If it uses all of them, what is the difference between "*" and "+"?
> It still doesn't explain why the disconnected clock doesn't get dropped.
>>> the clock (Spectracom) changes its stratum from 1 to 16 after a delay, and
>>If it remains the best choice it could take up to 8192 seconds before 
>>all the samples are flushed from the FIFO and it becomes completely 
>>ineligible.  There is logic to discourage early switching, as clock 
>>hopping is, itself, considered a bad thing.
> OK, is 8192 the default time before a nonresponsive host gets dropped?

No, 8 poll intervals, whatever your poll interval is. 

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