Microsoft KB Archive/945435

= You experience a long delay when you try to access to a WebDAV share for the first time on a Windows Vista-based computer =

Article ID: 945435

Article Last Modified on 12/3/2007

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APPLIES TO


 * Windows Vista Enterprise 64-bit Edition
 * Windows Vista Home Basic 64-bit Edition
 * Windows Vista Home Premium 64-bit Edition
 * Windows Vista Ultimate 64-bit Edition
 * Windows Vista Business
 * Windows Vista Business 64-bit Edition
 * Windows Vista Enterprise
 * Windows Vista Home Basic
 * Windows Vista Home Premium
 * Windows Vista Ultimate

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SYMPTOMS
When you try to access a Web Distributed Authoring and Versioning (WebDAV) share for the first time on a Windows Vista-based computer, you experience a long delay.

Additionally, you may experience the long delay during a later attempt to access a WebDAV share when the connection to the WebDAV workspace is closed.

Note If the connection to the workspace remains, you will not experience the long delay when you access the WebDAV share.



CAUSE
In Windows Vista, multiple UNC provider (MUP) tries all the network providers sequentially according to the information that is specified in the registry. By default, the Server Message Block (SMB) redirector comes first. Therefore, MUP must try the SMB provider before MUP tries the Distributed Authoring and Versioning (DAV) provider.

If the router is configured to drop TCP packets that are directed to SMB ports (port 139 and port 445), MUP waits until the SMB connection times out. Then, MUP tries the DAV provider. This behavior causes the long time delay.



RESOLUTION
A hotfix is available to resolve this problem. All calls to WebDAV shares are converted from HTTP paths to UNC paths. These conversion routines set DavWWWRoot as the share name. After you apply the hotfix, MUP checks the share name before MUP tries any network provider. If the share name is DavWWWRoot, the call will not be forwarded to the SMB connections. This behavior avoids the delay that occurs when MUP tries the SMB provider.

Hotfix information
A supported hotfix is now available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next service pack that contains this hotfix.

To resolve this problem, submit a request to Microsoft Online Customer Services to obtain the hotfix. To submit an online request to obtain the hotfix, visit the following Microsoft Web site:

http://go.microsoft.com/?linkid=6294451

Note If additional issues occur or any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. To create a separate service request, visit the following Microsoft Web site:

http://support.microsoft.com/contactus/?ws=support

Prerequisites
There are no prerequisites for installing this hotfix.

Restart requirement
You must restart the computer after you apply this hotfix.

Hotfix replacement information
This hotfix does not replace a previously released hotfix.

Registry information
To use one of the hotfixes in this package, you do not have to make any changes to the registry.

File information
The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.

Windows Vista, x64-based versions


WORKAROUND
To work around this problem, stop the Workstation service.

Note You cannot access the SMB share if the Workstation service is stopped.



STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the &quot;Applies to&quot; section.



MORE INFORMATION
For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:

824684 Description of the standard terminology that is used to describe Microsoft software updates

Keywords: kbfix kbqfe kbpubtypekc kbexpertiseadvanced kbhotfixserver KB945435

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