[ntp:questions] Windows NTP setup problem.

David Woolley david at ex.djwhome.demon.co.uk.invalid
Sat Feb 16 10:24:39 UTC 2008

Tualha Khan wrote:
> Hello Everyone,

> The platform is Windows 2003 x64. I am running the windows build of
> meinberg ntp server. 

I think you mean the Meinberg build of the reference implementation of 
ntpd.  All that Meinberg do is to compile and package the standard code, 
for Windows.  A version number might help, though.

> Basically, there are two servers which will preferably feed off an
> external time source, and in case the external time source is
> unreachable, they will feed off of each other. Since these machines are

Feeding off each other can only be done properly using the recently 
introduced orphan mode.  I've not used it, but I have a feeling that you 
do not specify local clocks in that case.  The alternative approach is 
to use a strict client server relationship and fudge the local clock 
stratums so that the client one is, numerically, at least two greater 
than the server one, although no more than 14.

Trying to peer with local clocks can cause all sorts of misbehaviour, 
and it is more or less essential that you provide enough real sources of 
time to outvote-them.

> The problem is that if I remove the external server reference from the
> ntp files on both the machines, and change the time on any one of them,

Please note that ntpd is not designed to handle this situation well. 
Time doesn't jump at one place but not another!

> the other one does not sync its time with this machine. It continues to
> run with a time gap, irrespective of how long I wait for it to sync. Am
> I doing something wrong here?

I imagine they both think the other machine is broken.

> Secondly, I don't understand what "fudge" means and difference between

The meaning of fudge comes from its sense of meaning cheat.

It should always be done with a local clock in this situation so that it 
appears to be so far from the root server that its bogus idea of the 
time cannot propagate very far.  Times derived more than 15 hops from 
the client are ignored, so fudging to 14 results in direct client s 
accepting the time, but any indirect ones ignoring it.  (Of course, some 
versions of w32time are broken, so if you use them as clients, they will 
set the stratum back to 2.)

> peer and server. I have read the documentation, but I am still not sure
> if I should be using my internal server's references as peer or server.

Server means that the client will use the time information that the 
server sends, but the server will ignore the information that the client 
sends, even though it will send it.  Peer means that:

1) at some times, one may nominate the other as its official reference
    reference source, at some time vice versa, and sometimes a completely
    different source may be used;

2) according to rules with which I'm not completely familiar, although
    I believe they have restrictions on trivial loops, and stratum
    difference, they can both use the other as one of the sources of time
    in the average of all usable servers used to discipline their own
    time.  Even if that works with two local clocks, it is not guaranteed
    to be stable.
> This message (and any associated files) is intended only for the use
> of the individual or entity to which it is addressed and may contain

Then why did you send it to the whole universe?

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