Server Rejects TreeConnectAndX and DirectorySearch SMB

• Microsoft Windows NT Workstation version 3.51
• Microsoft Windows NT Server version 3.51

SYMPTOMS

Some applications running on IBM OS/2 Lan Requester clients may fail when accessing files located on Windows NT server shares.

CAUSE

This problem happens when the Server Message Block (SMB) client chains the TreeConnectAndX and DirectorySearch commands in the same SMB.

Since Windows NT Server incorrectly rejects this SMB, the client application is prevented from working correctly.

This problem occurs when the connection to the share and the DirectorySearch are issued in the same SMB.

RESOLUTION

Using "map drive" instead of uniform naming convention (UNC) names prevents these commands from being chained together.

You can also resolve this problem by upgrading to Windows NT 4.0.

MORE INFORMATION

SMB specification allows some commands to be chained together in the same SMB. The Lan Manager 1.x book states that the DirectorySearch command is one of the authorized chained commands for TreeConnectAndX.

When the server rejects an SMB request, it also logs event 2006: "The server received an incorrectly formatted request from the server \\<server name>."

The data associated with this event shows the beginning of the rejected SMB and may help to identify the problem.

   0000: 00 00 34 00 02 00 7c 00   ..4...|.
   0008: 00 00 00 00 d6 07 00 c0   ....O..A
   0010: 00 00 00 00 01 20 98 c0   ......?A
   0018: 00 00 00 00 00 00 00 00   ........
   0020: 00 00 00 00 00 00 00 00   ........
   0028: 2f 06 00 00 ff 53 4d 42   /...ySMB
   0030: 75 00 00 00 00 08 00 00   u.......  -> 75 Tree Connect and X
   0038: 00 00 00 00 00 00 00 00   ........
   0040: 00 00 00 00 04 08 25 00   ......%.
   0048: 01 08 06 1a 03 81 00 31   .....?.1  -> 81 Directory Search
   0050: 00 01 00 08 00 41 3a 00   .....A:.

STATUS

Microsoft has confirmed this to be a problem in Windows NT version 3.51. We are researching this problem and will post new information here as it becomes available.