[ntp:hackers] Re: Conference Call

David L. Mills mills at udel.edu
Sat Nov 6 09:59:59 PST 2004


Jack,

You might want to pass this along to the troops. I observe three things 
for the Windows NT implementation. The first is that the service is 
allegedly based on a very old but still valid RFC for SNTP. However, if 
the XP implementation is in fact the NT implementation, the 
implementation is defective in that it uses an incorrect (symmetric) 
mode. Second, the local clock frequency is adjusted, although unclear 
how. Third, there is some attempt to mitigate between servers.

What this all means is that using the native Windows time service within 
a domain, while not optimal, might not be such a bad idea. I still 
believe that domain controllers should use the public NTP to synchronize 
with their servers.

See http://support.microsoft.com/default.aspx?scid=kb;en-us;223184. It 
looks like the public NTP for Windows should be modified to set the 
reliableTimeSource registry key according to whether synchronized or not.

Dave




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