"Brad Knowles" wrote in message
news:mailman.29.1111192970.588.questions@lists.ntp.isc.org...
> At 3:16 PM -0800 2005-03-18, David Schwartz wrote:
>> The assumption is that you have three servers, two of which are
>> working
>> and one of which is not. If two of them are working, then their
>> intervals
>> *must* overlap.
> They can't overlap, since it takes two machines to *define* an interval.
> If you have three machines, you may have as many as two different
> intervals. If one of those machines is insane, then you're back to the
> well-known two-machine problem.
A machine reports a time of X and it reports its own accuracy as Y and
the round trip time is Z. Why does this one machine not define an interval
X+Y+Z to X-Y-Z?
>> Obviously if you have three servers and no two of them
>> are
>> reliable, you are screwed.
>
> You're pretty much screwed if you have just three servers and any one of
> them is unreliable.
I don't see why. Common sense say that if you have three servers and
they report:
10:11
10:11
12:03
The time is probably 10:11.
DS
|