An FTP session that is copying a file from an FTP server appears to stop responding on a client computer that is running Windows Server 2003

Consider the following scenario:

• On a client computer that is running Microsoft Windows Server 2003, you connect to an FTP server.
• Windows Firewall is installed on the client computer.
• You run separate FTP sessions on the client computer to copy files of different sizes from the FTP server.
• The FTP session that is copying the smaller file finishes its copy operation.

In this scenario, the FTP session that is copying the larger file appears to stop responding (hang).

This problem occurs because the Windows Firewall driver (Ipnat.sys) incorrectly closes the FTP session that is copying the larger file instead of closing the FTP session that is finished copying the smaller file.

Service pack information

To resolve this problem, obtain the latest service pack for Windows Server 2003. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

Hotfix information

A supported hotfix is 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 software update that contains this hotfix.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if 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. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site: Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.

Prerequisites

No prerequisites are required.

Restart requirement

You must stop and start the firewall service on the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other hotfixes.

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 Server 2003, Itanium-based versions

Windows Server 2003, x64-based versions

Windows Server 2003, x86-based versions

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section. This problem was first corrected in Windows Server 2003 Service Pack 2.

For more information, click the following article number to view the article in the Microsoft Knowledge Base: