[ntp:questions] Synchronization and Non-Synchronization status

David Woolley david at ex.djwhome.demon.invalid
Sat Feb 20 10:28:42 UTC 2010

Jaiprabhu wrote:

> I have observed that the server reaches the reject state, while the 
> stratum stays the same (it was at 1), a long time after it moved into 
> the reject state. The server was moved to the reject state by making it 
> unreachable by adding it's IP in an iptables drop rule. The reject state 
> already means that the server is not a synchronization source. What's 
> the rule of thumb on the duration it would take for the stratum shifting 
> to 16?

It should shift when the last available sample is too old to really 
correlate well with the true time.  There is a definite drop dead when 
the root dispersion reaches about a second.  I thought that the stratum 
collapses when somewhere between about 4 and 6 polls have been lost, but 
it might not be until the estimated error (root dispersion) becomes too 

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