[ntp:questions] Windows built-in SNTP/NTP clients

Ryan Malayter malayter at gmail.com
Thu Aug 14 12:58:38 UTC 2008

On Wed, Aug 13, 2008 at 11:56 AM, David L. Mills <mills at udel.edu> wrote:
> Neither does Windows implement the mode-6 protocol nor does it conform
> to the basic protocol.

Microsoft claims otherwise:
"The Windows Time service integrates NTP version 3 with algorithmic
enhancements from NTP version 4"
from http://technet.microsoft.com/en-us/library/cc773013.aspx
There are plenty of references to RFC 1305 on those pages.

The only strange behavior I've observed from Windows Time Service
>2003 is the use of symmetric-active associations as a default.
However, that is not a non-compliance problem, as client-mode
associations are easily configured explicitly. It is just a stupid

Now the lack of support for broadcast and multicast modes may be
grounds for calling the implementation, but the RFC is a bit unclear
as to whether all modes are required. The use of the standard RFC 221

> As the author of rfc1305 I say you misquote me. The mode-6 control and
> monitoring protocol is an integral component of the specification; the
> mode-7 protocol is intended as propietary. In any case the mode-6
> protocol was defined and implmented well before SNMP.

>From RFC 1305 Appendix B, paragraph 1:
"These messages are intended for use only in
systems where no other management facilities are available or
appropriate, such as in dedicated-function bus peripherals. Support for
these messages is not required in order to conform to this

Now David, you may have *meant* something else, but what you wrote
into RFC 1305 seems pretty clear. The first sentence quoted above
clearly indicates that mode 6 packets are *not* the preffered method
for management and monitoring of NTP systems. Any NTP implementer -
even Microsoft - cannot be taken to task accountable for following the
recommendations of RFC 1305!


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