NetBT Tears Down TCP Session with Multiple Concurrent File Transfers (161968)

SYMPTOMS

Copying files from one computer running Windows NT to a UNC path on a second computer running Windows NT may fail if the Windows NT machine is under heavy stress. This usually occurs when there are multiple, concurrent, file transfers in progress. If the file transfers are initiated by an application, the application initiating the file transfer may log events with error 59 ("An unexpected network error occurred"). A network sniff of the failure will show a TCP RESET segment being sent by the computer running Windows NT that is doing the writing.

CAUSE

When under a heavy load, Windows NT may send multiple server message blocks (SMBs) in the same network segment. Rdr.sys was incorrectly assuming the response to the Session Setup & X would be the only SMB in the segment and was taking more data than it should.

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

152734 How to Obtain the Latest Windows NT 4.0 Service Pack

To resolve this problem, obtain the following fix for Windows NT 3.51:

   01/26/98  04:58p               260,384  Rdr.sys (Intel)
   01/26/98  04:55p               471,664  Rdr.sys (Alpha)

NOTE: Service Pack 5 must be applied to Windows NT 3.51 prior to applying this fix.

STATUS

Microsoft has confirmed that this is a problem in Windows NT 4.0 and Windows NT Server 4.0, Terminal Server Edition. 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.

Microsoft has confirmed this to be a problem in Windows NT version 3.51. A supported fix is now available, but is not fully regression tested and should be applied only to systems experiencing this specific problem. Unless you are severely impacted by this specific problem, Microsoft recommends that you wait for the next Service Pack that contains this fix. Contact Microsoft Product Support Services for more information.