[ntp:questions] Re: w32tm UDP Port

Richard B. Gilbert rgilbert88 at comcast.net
Thu Jun 23 19:26:45 UTC 2005

stonecoldfan1 at hotmail.com wrote:

>Not a regular poster, don't blast me too hard.
>I am running a small group of servers (Win2K, sp4) in a protected zone.
> One server is set up as the 'time server', the rest as clients.
>The time server is not 'official' by any means, but we needed to
>sync all the times on the servers to each other.
>Despite being in this protected zone, I am required (on each server) to
>restrict the TCP/IP settings.  I originally thought that allowing UDP
>on port 123 would be enough, but as soon as I placed the restriction on
>the client, I was not able to sync up anymore.
>I ran a sniffer and found that the request from the client goes to UDP
>port 123 on the server...but is generated from a seemingly random port
>on the client.  The time server sends the datagram back to the client
>from 123 to the previously mentioned random port (and is blocked, of
>Using w32Time, is there a way to control the port(s) that the time sync
>request is made on in order to allow the reply to get through?
W32Time is a brain damaged Microsoft implementation of SNTP.  You need 
to ask Microsoft how to fix it.  (Lots of luck!!)

If you download and install the Windows version of ntpd, someone here 
might be able to help you control what port(s) it uses.  It might even 
do the right thing all by itself!   Sorry, I can't supply a link to a 
site from which you can download the Windows version; attempts to reach 
ntp.isc.org from here are timing out at the moment.

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