Microsoft KB Archive/925442

= Files may become corrupted when you use an Intel PRO/10GbE network adapter that has TCP segmentation offload enabled on a Windows Server 2003-based computer =

Article ID: 925442

Article Last Modified on 10/11/2007

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APPLIES TO


 * Microsoft Windows Server 2003, Standard Edition (32-bit x86)
 * Microsoft Windows Server 2003, Enterprise Edition
 * Microsoft Windows Server 2003, Datacenter Edition (32-bit x86)
 * Microsoft Windows Server 2003, Standard x64 Edition
 * Microsoft Windows Server 2003, Enterprise x64 Edition
 * Microsoft Windows Server 2003, Datacenter x64 Edition
 * Microsoft Windows Server 2003, Enterprise Edition for Itanium-based Systems
 * Microsoft Windows Server 2003, Datacenter Edition for Itanium-Based Systems

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SYMPTOMS
Consider the following scenario:
 * You use one of the following network adapters on a Microsoft Windows Server 2003-based computer that is part of a network:
 * Intel PRO/10GbE LR
 * Intel PRO/10GbE SR
 * TCP segmentation offload is enabled on this network adapter.
 * You use this network adapter to transfer files between the Windows Server 2003-based computer and a different computer that is on the network.

In this scenario, the files that are transferred may become corrupted.



CAUSE
This problem occurs because the remote file I/O function for the driver that the network adapter uses does not work correctly when TCP segmentation offload is enabled. The network adapter uses the remote file I/O function to transfer the data for the files. When the network adapter receives a request to transfer lots of data, TCP segmentation offload divides the data into smaller segments of data. The remote file I/O function incorrectly stops processing these smaller segments of data before the network adapter sends all the data. Therefore, the files become corrupted.



MORE INFORMATION
To troubleshoot this problem, disable TCP segmentation offload on this network adapter. To do this, follow these steps:
 * 1) On the Windows Server 2003-based computer that uses this network adapter, click Start, click Run, type ncpa.cpl, and then click OK.
 * 2) Right-click the network connection that you use for this network adapter, and then click Properties.
 * 3) Click the General tab, and then click Configure.
 * 4) Click the Advanced tab.
 * 5) In the Property area, click Offload TCP Segmentation.
 * 6) In the Value list, click Off, and then click OK.

Note To enable TCP segmentation offload, follow steps 1 through 6, but click On instead of Off in step 6.

Technical support for x64-based versions of Microsoft Windows
If your hardware came with a Microsoft Windows x64 edition already installed, your hardware manufacturer provides technical support and assistance for the Windows x64 edition. In this case, your hardware manufacturer provides support because a Windows x64 edition was included with your hardware. Your hardware manufacturer might have customized the Windows x64 edition installation by using unique components. Unique components might include specific device drivers or might include optional settings to maximize the performance of the hardware. Microsoft will provide reasonable-effort assistance if you need technical help with a Windows x64 edition. However, you might have to contact your manufacturer directly. Your manufacturer is best qualified to support the software that your manufacturer installed on the hardware. If you purchased a Windows x64 edition such as a Microsoft Windows Server 2003 x64 edition separately, contact Microsoft for technical support.

For product information about Microsoft Windows XP Professional x64 Edition, visit the following Microsoft Web site:

http://www.microsoft.com/windowsxp/64bit/default.mspx

For product information about x64-based versions of Microsoft Windows Server 2003, visit the following Microsoft Web site:

http://www.microsoft.com/windowsserver2003/64bit/x64/default.mspx



RESOLUTION
To resolve this problem, install the latest drivers for this network adapter. To obtain the latest drivers for this network adapter, visit the following Microsoft Windows Update Web site:

http://windowsupdate.microsoft.com

