Ethernet Packet Size Incorrectly Determined w/ Packet Burst Off

 Last reviewed: April 10, 1997
Article ID: Q150426
The information in this article applies to:
  • Microsoft Windows NT Workstation version 3.51
  • Microsoft Windows NT Server version 3.51

SYMPTOMS

When you turn off Packet Burst on Windows NT 3.51 , the computer may not be able to copy files larger than 1450 bytes to or from a Novell server over Ethernet. The copy can also fail if the NetWare server does not have Packet Burst turned on and Packet Burst is enabled on Windows NT. Most versions of NetWare have Packet Burst enabled by default, but NetWare Version 3.11 does not. This problem does not occur on Windows NT 3.5.

You may receive one of the following error messages: 

   File Manager cannot copy <filename>: The remote computer is not
   available.
-or- 

   File Manager cannot copy <filename>: Error performing inpage operation.

CAUSE

When Packet Burst is turned off on Windows NT 3.51, the computer fails to negotiate the proper packet size for Ethernet and attempts to use a packet size which is too large. Negotiations occur properly if Packet Burst is turned on.

RESOLUTION

You can use either one of the following resolutions:

Resolution 1

  1. Make sure Packet Burst is turned on for both Windows NT and the NetWare
server. 

   WARNING: Using Registry Editor incorrectly can cause serious, system-
   wide problems that may require you to reinstall Windows NT to correct
   them. Microsoft cannot guarantee that any problems resulting from the
   use of Registry Editor can be solved. Use this tool at your own risk.

  • Run Registry Editor (REGEDT32.EXE).

  • From the HKEY_LOCAL_MACHINE subtree, go to the following key: 

          \SYSTEM\CurrentControlSet\Services\NWCWorkstation\Parameters

  • Check for the following entry: 

          MaxBurstSize:REG_DWORD: 0

  • If the value is present, delete the value. Do not change this entry to 1, because Packet Burst will not be turned in Windows NT 3.51.

  • Choose OK and quit Registry Editor.

  • Shut down and restart Windows NT.

    NOTE: On the NetWare Server make sure that the PBurst NetWare loadable module (NLM) is loaded. This is only necessary in Version 3.11, because the NLM is enabled by default in later versions.

    Resolution 2

    1. Edit the Registry of the Windows NT computer to change the packet size being used by Windows NT.

      WARNING: Using Registry Editor incorrectly can cause serious, system-wide problems that may require you to reinstall Windows NT to correct them. Microsoft cannot guarantee that any problems resulting from the use of Registry Editor can be solved. Use this tool at your own risk.

    2. Run Registry Editor (Regedt32.exe).

    3. From the HKEY_LOCAL_MACHINE subtree, go to the following key: 

            \SYSTEM\CurrentControlSet\Services\NwRdr\Parameters

    4. Add the following value: 

            DefaultMaxPacketSize:REG_DWORD: 1450(decimal)5aa(Hex).

    Note: This change will force the proper packet size.

    MORE INFORMATION

    For additional information, please see the following article in the Microsoft Knowledge Base:

    ARTICLE-ID: Q134385 

    TITLE     :

    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 in the Microsoft Knowledge Base as it becomes available.

    • Additional query words: prodnt copy GSNW CSNW
    Keywords : kbnetwork ntinterop NTSrvWkst
    Version : 3.5 3.51
    Platform : WinNT

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    Last reviewed: April 10, 1997
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