[ntp:questions] Re: Howto synchronize a ntp client (Linux) with a server running w32time (Win 2000)?

David Woolley david at djwhome.demon.co.uk
Wed Mar 2 21:03:55 UTC 2005

In article <4225fd07$0$44063$5fc3050 at dreader2.news.tiscali.nl>,
philippe.reis at tiscali.be wrote:

> How to synchronize a NTP client (Linux) with a server running w32time (Win 2000)?

Not legally.  NTP requires an NTP server to work to specification.  If enough
fields are set appropriately in the reply, you might be able to in practice,
but you really should make Windows the leaf node and *nix the server,
as Windows is about the worst common platform, even when running the
reference implementation.

> My Win 2000 is not synchronized with "the real time" but I would like
** to use it as a time server for the others machine.

Looking further down, it isn't synchronized to a fake time either.  It simply
isn't synchronized.  No compliant NTP or SNTP server will synchronize to it.

> The problem is that YATS is not free and it expires in few days.

I fail to see why a market niche would exist for such a product, given that
full NTP is free and the OpenNTP SNTP client is also free.  Maybe it is
because people are prepared to pay to not be told the server is broken.

> Is it possible to synchronize an NTP client with a server running w32time?

It is possible with some versions of w32time, if they are themselves 
synchronised, although it will not be acting as a true NTP client.

> I read somewhere that w32time on Windows is a SNTP server and not a real NTP.

Worse than that, it is a broken SNTP server.

> Does a Linux SNTP client exist?

OpenNTP and (although some builds don't work) the one that comes with the
reference NTP, but if either of these synchs to the server that produced the
results below, please raise a bug report against it as it's broken.

> stratum 16, precision -20, leap 11, trust 000

Stratum 16 is "not synchronized" - server cannot be used
Leap 11 is ***ALARM***  - server cannot be used

> reference time:    00000000.00000000  Thu, Feb  7 2036  7:28:16.000

Reference time 0 is "never been synchronised"  - server cannot be used

You have a server that is telling clients not to use it in three
different ways.  Anything that does use it is broken.

> originate timestamp: c5d0438c.1d7635e7  Wed, Mar  2 2005 14:52:12.115
> transmit timestamp:  c5d04393.0ac61522  Wed, Mar  2 2005 14:52:19.042

Looks as though you have everything you need other than the lack of

> filter delay:  0.02608  0.02579  0.02579  0.02579
>           0.02579  0.02579  0.02579  0.02579

25ms delay is very bad for a LAN.  You should expect this sort of delay
over broadband WAN, but is not surprising for a Windows based server.

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