Clock accuracy stats

I installed and setup NTP on my PC as a client, using the server
time.nist.gov. I would like to view accuracy statistics. I tried the
"ntpq -p" command, but I get the error: "No association ID's
returned".

I also downloaded and installed NTPmonitor, but it says the
status of each of the default list of servers (time.nist.gov, etc.) is
unknown, and says that it is "disconnected" from each of them.

I am running on Windows Vista, but the NTP software (and
NTPmonitor) is installed in another directory, not the standard
"Program Files" directory that can result in problems (cannot write to
it).

Thanks, Alan

Alan wrote:[color=blue]
> I installed and setup NTP on my PC as a client, using the server
> time.nist.gov. I would like to view accuracy statistics. I tried the
> "ntpq -p" command, but I get the error: "No association ID's
> returned".
>
> I also downloaded and installed NTPmonitor, but it says the
> status of each of the default list of servers (time.nist.gov, etc.) is
> unknown, and says that it is "disconnected" from each of them.
>
> I am running on Windows Vista, but the NTP software (and
> NTPmonitor) is installed in another directory, not the standard
> "Program Files" directory that can result in problems (cannot write to
> it).
>
> Thanks, Alan[/color]

Alan,

In your firewall software, please ensure that both NTPD and NTPQ have both
incoming and outgoing Internet access allowed. (Outgoing alone may be
enough). Restart NTP.

If that is OK, either check the server list for NTP, or look in the event
viewer to see any error messages from the NTP application.

Cheers,
David

Alan wrote:[color=blue]
> I installed and setup NTP on my PC as a client, using the server
> time.nist.gov. I would like to view accuracy statistics. I tried the[/color]

Incidentally, that server is heavily overloaded and is unlikely to be a
good choice compared with a nearby stratum 2 server. As a general
principle leaf nodes shouldn't be using stratum one servers. For
non-critical, personal, systems the servers provided by any competent
ISP should do.
[color=blue]
> "ntpq -p" command, but I get the error: "No association ID's
> returned".[/color]

I'd assume that it has failed to read the configuration file and has
started without any servers. I think it might also happen if you fail
to resolve the domain names, which might be a service dependency issue.

With regard to the subject, these tools cannot tell you the accuracy of
the clock, they can only give you information about the quality of the
time measurements that are being made. In particular, providing you are
getting offsets scattered evenly around zero, the clock's variation is
likely to be a lot less than the offsets you are seeing, but there may
be a systematic bias in the time that is not reflected in the statistics.

On 2008-06-16, David Woolley <david@djwhome.demon.co.uk>
wrote:
[color=blue]
> Alan wrote:
>[color=green]
>> I installed and setup NTP on my PC as a client, using the server
>> time.nist.gov. I would like to view accuracy statistics. I tried the[/color]
>
> Incidentally, that server is heavily overloaded and is unlikely to be
> a good choice compared with a nearby stratum 2 server. As a general
> principle leaf nodes shouldn't be using stratum one servers. For
> non-critical, personal, systems the servers provided by any competent
> ISP should do.[/color]

In addition to one's ISP, sources for Public Time Servers include:

* The Stratum 2 Time Server List at [url]http://support.ntp.org/s2[/url]

* The NTP Pool at [url]http://support.ntp.org/pool[/url] or [url]http://www.pool.ntp.org/[/url]

--
Steve Kostecke <kostecke@ntp.org>
NTP Public Services Project - [url]http://support.ntp.org/[/url]