[ntp:questions] ntpdate refusing ntp.nmi.nl

David Woolley david at ex.djwhome.demon.co.uk.invalid
Sat Jan 10 00:00:53 UTC 2009


Folkert van Heusden wrote:
> 
> Ok so the root dispersion is not too high if I understand you correctly
> (well it would be better if it were lower)

The root dispersion is consistent with having a very old reference time. 
  The reference time is too old, which means the root dispersion is too 
high.  It is the high root distance (which includes the root dispersion) 
that is causing the server to be rejected.


> The systems I checked that sync to this server (and others, of course)
> seem to ignore it:
> 
> *GENERIC(0)      .DCFa.           0 l   55   64  337    0.000   -2.421   2.390
> +adsl.remco.org  .GPS.            1 u  504 1024  377   19.581    3.159   0.188
> ...
>  ntp.nmi.nl      .IRIG.           1 u  535 1024  377   12.146   52.565   0.044
> 
> 
> The reason that I keep on going on this system is that I would like to
> have them get it to also work with ntpdate and such and not only the
> windows implementation. The reasons for them to fix it I come up with is

It is not working with nptd, either.  There is no character in front of 
it, which means that it is being rejected.  If you do rv for the 
association, you will see a code indicating that the the distance is too 
high.

> now:
> - root dispersion too high

and therefore root distance is too high, and therefore it is rejected as 
a source.

> - offset too high; 52ms (tried from ADSL, cable and SDSL connected

The very large root distance would make 52ms highly acceptable, if the 
clock weren't being rejected.  52ms is well within the, nearly, 4,000ms 
uncertainty.

In reality, this figure could either represent that it really has been 
unsynchronised for three days, but is drifting at rather less than 15ppm 
(and 15ppm is really rather pessimistic), or that you have a calibration 
error on your PPS input.

>   systems, synced to GPS+PPS, DCF77, MSF and systems on the internet)
> - reference time too old

DCF is not good for very high accuracy time.

Someone mentioned that this machine is only intended for synchronising 
Windows.  I don't believe that w32time performs a root distance check on 
its servers.




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