NTP Client synchronization with a Windows 2003/2008

Jon Radel jon at radel.com
Tue Oct 13 16:02:45 UTC 2009

Jacques Henry wrote:
> Hello,
> I am using a System based on FreeBSD 6.3.
> On this System an automatically generated ntpd.conf file is generated in
> order to synchronize the System clock with a NTP Server. I want to use a
> Windows 2003 or 2008 Server to act as the NTP Server. On the Windows System
> the NTP Server (Windows Time Service) is *correctly* running. The thing is
> that even if there are NTP traffic between the client and the Server (NTP
> Client and Server IP packet), My FreeBSD is not synchronizing at all:
> freebsd-client>ntpq -p
>      remote           refid      st t when poll reach   delay   offset
> jitter
> =======================================================
>  NTP_server     2 u  103 1024    1    1.037  -587367
> 0.002
> As you can see the offset is huge and never decreases as in a normal way...
> My ntpd.conf file looks like:
> -----------
> # File is automatically generated
> # Do not edit
> tinker panic 1
> tinker step  1

My man page for ntp.conf clearly states in regards to the tinker command:

The default values of these variables have been carefully optimized for 
a wide range of network speeds and reliability expectations.  In 
general, they interact in intricate ways that are hard to predict and 
some combinations can result in some very nasty behavior.
Very rarely is it necessary to change the default values; but,
some folks cannot resist twisting the knobs anyway and this com-
mand is for them.  Emphasis added: twisters are on their own and
can expect no help from the support group.

so the very first thing you might want to try is to comment out the 
tinker commands, in particular the panic one. I'm not sure that after 
you set the panic threshold to 1 second you should expect your ntpd to 
pay any attention to servers with an offset of 587 seconds. If that 
fails, consider setting


in your /etc/rc.conf and simply stepping to the correct time at boot time.

In short, I don't think this has anything with a Windows server being 
involved, and everything to do with starting off almost 10 minutes off 
and a config file that says to never make a step correction larger than 
1 second and to panic if you see an offset of over 1 second.


--Jon Radel
jon at radel.com
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