[ntp:questions] Local DCF77 clock is rejected in favour of remote ISP stratum 1s (was: Help appreciated)

David Woolley david at ex.djwhome.demon.co.uk.invalid
Wed May 13 11:27:43 UTC 2009

Towli wrote:

> What i dont get ,is that the precison of 2**-6 seems to steem from 
> which is the DCF77 appliance box (that is - not a switch) 
> on my internal network. How come it has this low precision ? is it bad 
> hardware could it be bad network connection/ bandwidth?

Precision is determined by local hardware and software.  A poor 
precision tends to be the result of using 10ms or longer clock ticks, 
without reading the residual count, or other means of interpolation. 
Nowadays, the main source of such low precision is w32time.

> Below is an output of one of my client switches, getting its time from 
> the core switches (which then in turn is synching with the mentioned 
> aplliance box). -Here the precision is better (?).

Precision is a local issue.  The upstream precision is factored into the 
root dispersion.

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