[ntp:questions] Peer's stratum is less than Host's stratum

David Woolley david at djwhome.demon.co.uk
Fri Dec 8 08:03:41 UTC 2006

In article <1165511202.941746.78800 at f1g2000cwa.googlegroups.com>,
jjxjjx <jjxjjx2003 at yahoo.com> wrote:

> Subject: Peer's stratum is less than Host's stratum

Peers are not the same as clients, and you shouldn't be configuring them
unless you really know what you are doing.

> i got this message when trying to sync system clocks on win 2003.

In any case, I can't find this message anywhere in version 4.2.0 of the
reference implemntation.

Which implementations and versions are you using.  Note that the 
service pack level of Windows 2003 is important if you are using W32Time.
(Although, as the source code and detailed documentation for W32Time are
not available outside Microsoft, they are the best people to ask about
that implementation.)

> Using ethereal i see packets between client and server.
> Client is intruducing itself as Client but has Stratum 1

That should only be true if it has a directly attached and working
references clock, in which case it doesn't need an external server.
Even the early versions of W32Time didn't start reporting a synchronised
stratum until they had been synchronised once, and, even then, reported
stratum 2 (regardless of the source!!!).

Remove the reference clock from the configuration, or replace the 
client with a working NTP implementation.

> Server is intruducing itself as Server bu has Stratum 15

I think this is correctly synchronised to a stratum 14 reference clock,
which is the most paranoid setting for the local clock driver.  Assuming
the network is only two levels, there is no valid reason for configuring
the local clock with any better a stratum.

> We configured server with some NTP server tool that has reference to
> Local System time on server.

What tool?  What parameters did you use?  Normally people configure the
local clock by directly editing the configuration file, and are able
to quote its contents here.

> Is it possible to force stratum on machine?

No, it is only possible to force the stratum on a reference clock, but
you should never need to force the local clock to anything numerically
lower than 15 minus the largest number of NTP network hops to a client.

As has already been noted, many of the assumptions in NTP are based on
the idea that time is eventually traceable to Universal Coordinated
Time, rather than the random measure of time produced by some PC's clock.
As such, using the local clock as a first choice source is never the
best solution.

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