The FTP PORT Command Fails in IIS 3.0 When the System Has Multiple Network Interface Cards

• Microsoft Windows NT Workstation version 4.0
• Microsoft Windows NT Server version 4.0
• Microsoft Internet Information Server version 3.0

SYMPTOMS

There is the possibility that, when the PORT command is sent to the FTP services on a Microsoft Internet Information Server (IIS) version 3.0 system that has more than one network interface card, the PORT command will fail with the following error:

Error 425, can't open data connection

CAUSE

When the FTP server connects to the client's data socket, IIS 3.0 will bind the socket to the first available address on the system. After applying this patch IIS 3.0 will now bind to the address of the user initiating the request.

RESOLUTION

To resolve this problem, obtain the latest service pack for Windows NT 4.0 or Windows NT Server 4.0, Terminal Server Edition. For additional information, please see the following article in the Microsoft Knowledge Base:

Q152734 How to Obtain the Latest Windows NT 4.0 Service Pack

STATUS

Microsoft has confirmed this to be a problem in Microsoft Internet Information Server version 3.0. This problem was first corrected in Windows NT 4.0 Service Pack 4.0 and Windows NT Server 4.0, Terminal Server Edition Service Pack 4.

Additional query words:

Keywords : NT4SP4Fix kbbug4.00 kbfix4.00.sp4
Version : WinNT:3.0,4.0
Platform : winnt
Issue type : kbbug