[cifs-protocol] RE: Registry Setting to change NTP clients not to run as 'symmetric active'

[Hongwei Sun]

Andrew,

   Thank you for the feedback regarding Microsoft implementation of NTP client modes.

   Actually, in Windows Behavior  of  [MS-SNTP], the section below describes how Windows clients set the Mode field.

[MS-SNTP]  Windows Behavior <13>

In Windows 2000, the client always sets the Mode field of its Client NTP Request messages to 0x3 ("Client"). In Windows XP, Windows Server 2003, Windows Vista, and Windows Server 2008, a client that is also a time source sets the Mode field of its Client NTP Request messages to 0x1 ("Symmetric Active"), while a client that is not a time source sets the Mode field in its Client NTP Request messages to 0x3 ("Client"). By default, a client running on a domain controller is also a time source. The syntax and semantics for the Mode field of the Client NTP Request message are specified in [RFC1305] Appendix A.

Thanks !



-----Original Message-----
From: Andrew Bartlett [mailto:abartlet at samba.org]
Sent: Wednesday, June 11, 2008 6:14 PM
To: Hongwei Sun
Cc: pfif at tridgell.net; cifs-protocol at samba.org
Subject: Re: Registry Setting to change NTP clients not to run as 'symmetric active'

On Wed, 2008-06-11 at 09:26 -0700, Hongwei Sun wrote:
> Andrew,
>
>
>
>    In Window XP and Window 2003, the mode of client used to
> synchronize with time server is specified in registry key HKLM\SYSTEM
> \CurrentControlSet\Services\W32Time\Parameters\NtpServer.

Sure, but my point is that the protocol docs do not indicate Microsoft's unfortunate behaviour in this area (clients should be clients, not
symmetric active), even in the windows-specific behaviours section.

I'm well aware that the registry setting can be modified, but in terms of interoperability the pain comes from existing clients over which a server implementer does not have control.

The fundamental flaw is in Microsoft's implementation in this case.

Andrew Bartlett

--
Andrew Bartlett
http://samba.org/~abartlet/
Authentication Developer, Samba Team           http://samba.org
Samba Developer, Red Hat Inc.