[cifs-protocol] RE: Registry Setting to change NTP clients not to
run as 'symmetric active'
hongweis at microsoft.com
Fri Jun 13 19:52:37 GMT 2008
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.
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:
> In Window XP and Window 2003, the mode of client used to
> synchronize with time server is specified in registry key HKLM\SYSTEM
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.
Authentication Developer, Samba Team http://samba.org
Samba Developer, Red Hat Inc.
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