DOCUMENT:Q140536  23-FEB-2000  [foxpro]
TITLE   :PRB: "TDS buffer length too large" Error with SQL Server
PRODUCT :Microsoft FoxPro
PROD/VER:WINDOWS:2.5,3.0
OPER/SYS:
KEYWORDS:kbnetwork kbvfp300 kbMDAC250

======================================================================
-------------------------------------------------------------------------------
The information in this article applies to:

 - Microsoft Visual FoxPro for Windows, version 3.0 
 - Microsoft Data Access Components version 2.5 
-------------------------------------------------------------------------------

SYMPTOMS
========

When you try to connect to a data source on a SQL Server, you may receive an
error, which may be intermittent, that is similar to this:

   [Microsoft][ODBC SQL Server Driver]TDS buffer length too large(#0)

CAUSE
=====

This often shows up on workstations running Windows for Workgroups 3.11, servers
that were originally running Windows NT 3.1 but have been upgraded to Windows NT
3.5 or 3.51, and on systems using named pipes over Microsoft's NWLINK network
redirector.

NWLINK is Microsoft's IPX/SPX compatible network redirector. Windows NT 3.5
introduced a new feature called Direct Hosting, where the workstation and server
bypass the NETBIOS layer of the protocol. This allows the two to talk more
directly, eliminates a layer of overhead, and generally speeds
workstation/server interactions. However, when direct hosting is used with older
versions of the redirector, communications become unreliable.

RESOLUTION
==========

There are basically two resolutions, either replace the redirector or turn off
direct hosting. It is best to update the redirector to retain the speed of
direct hosting and to use the most recent versions of the drivers.

To replace the redirector, you need to find the files that comprise it and copy
them to the Windows\System subdirectory. The updated files are:

   NDIS.386
   NET.EXE
   NETAPI.DLL
   NWNBLINK.386
   VNETSUP.386
   VREDIR.386

They can be found on the Windows NT compact disc. For Windows NT 3.5, they are
located in \Clients\Wfw\Update. Note that these files are only for Windows for
Workgroups 3.11.

To turn off direct hosting, open the System.ini file on the Windows for
Workgroups client, find the [network] section, and add this line:

      DirectHost=off


STATUS
======

Microsoft is researching this behavior and will post new information here in the
Microsoft Knowledge Base as it becomes available.

Additional query words: connection VFoxWin

======================================================================
Keywords          : kbnetwork kbvfp300 kbMDAC250 
Technology        : kbVFPsearch kbAudDeveloper kbMDACSearch kbMDAC250 kbVFP300
Version           : WINDOWS:2.5,3.0
Issue type        : kbprb

=============================================================================

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS
PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND.  MICROSOFT DISCLAIMS
ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  IN NO
EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR
ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL,
CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF
MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGES.  SOME STATES DO NOT ALLOW THE EXCLUSION
OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES
SO THE FOREGOING LIMITATION MAY NOT APPLY.

Copyright Microsoft Corporation 2000.