[time-nuts] Win XP and NIST time

Chris Albertson albertson.chris at gmail.com
Tue Mar 26 11:30:47 EDT 2013

On Tue, Mar 26, 2013 at 12:41 AM, Hal Murray <hmurray at megapathdsl.net> wrote:
> davidwhess at gmail.com said:
>> I have had trouble with the built in XP NTP client where it fails silently
>> so I usually install Tardis which keeps an easy to read log which includes
>> performance data.
> One of the problems with timekeeping is the load on the servers.
> The standard ntpd package tries hard to be a good citizen.
> I don't know the current status, but Tardis is a good example of a bad guy.
> Lots of other systems are also buggy.   Here is a wonderful summary:
>   http://en.wikipedia.org/wiki/NTP_server_misuse_and_abuse

I would think that the best cure for persistent server abuse (abuse
that continues even after a KoD is sent) would be to send back a bogus
time with a huge random error of many thousands of hours.  A normal
NTP client will notice the error and stop sending requests and the
simple ntp clients in Windows and home routers will annoy their users
so much they would get disconnected.

A lot of people don't understand how NTP works and think sending many
packets will work better.   It is simple to understand if you think
about how to set a real mechanical wall clock.    The goal is to set
the "fast/slow" lever to the "correct" position.  So you set you clock
to match a standard clock then wait and after waiting you look at the
offset from the standard.  The LONGER you wait the better.  NTP's goal
is to adjust the rate of your clock.  At first it waits a short time
then as your clock's rate gets closer to correct it waits longer and
longer.  The longer times are actually a good sign.  BUT somehow
people think forcing a one second or one minute interval is better.

Chris Albertson
Redondo Beach, California

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