Troubleshooting Lost Network Connections

This article was previously published under Q90226
Retired KB Content Disclaimer
This article was written about products for which Microsoft no longer offers support. Therefore, this article is offered "as is" and will no longer be updated.
3.10 3.11
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This article provides troubleshooting steps and suggestions that mayassist you in solving network connectivity problems. Microsoft cannotguarantee the success of any specific steps provided in this article.
Windows for Workgroups may sometimes lose (drop) network connections.This problem is most likely to occur if one of the following conditionsexists:

  • You are running a network installation (SETUP /N) of Windows for Workgroups.

    NOTE: Microsoft does not recommend running Windows for Workgroups from a network installation (SETUP /N) because doing so is a common stress condition that can cause a loss of network connections. If your system is run this way, store data and applications on a client or server that does NOT contain the shared Windows directory (created with SETUP /A); this appears to reduce the frequency of the problem.
  • Several people in a workgroup are running the same application from a server.

    NOTE: Network connections also can be lost when many users run the same application from a server (for example, 10 clients use the same installation of Microsoft FoxPro for MS-DOS). MS-DOS-based applications seem most susceptible to this problem, but Windows-based applications can be affected as well. Windows-based applications generally report segment load failures when the network connection is lost. MS-DOS-based applications that leave a lot of files open, such as database programs, are more susceptible to this problem.
If network connections are lost or dropped, the system or applicationmay stop responding(hang), the network installation of Windows forWorkgroups may become corrupted, and MS-DOS-based applications may produceunexpected results.

WARNING: If you lose your Windows for Workgroups connections, immediatelysave all open data files to backup files on your local drive or a remotedrive where you still have a valid connection.
Loss of network connections can occur when you use any version of theredirector, but the basic redirector, invoked by using the "NET STARTBASIC" command, is most likely to have this problem. The problem seems tobe caused by a timing issue in the NetBEUI protocol. It may also be relatedto the network buffer size because it occurs when data is being sent overthe wire. In testing, this problem didn't occur unless the system wasrunning under the conditions listed above; however, the problem may occurwhen a system is not under any stress, but this is very rare.

Other factors that can cause connection problems include the following:

  • Network cards: Some network cards are more prone to these problems than others.
  • Machine speed: The slower the machine, the more likely that its network connections may be lost.
This problem usually originates with the server but affects clientsonly.

Attempting to Recover

To determine if you have lost network connections, go to the server and useNet Watcher to see if the machine that is not responding still has a validsession open. This method does not always work because some applicationscan reopen the network connections. Some applications may not be affectedby a lost network connection if they are not dependent on file pointersbeing maintained on the server.

Sometimes you can issue the NET USE command at the command prompt todetermine whether or not a session has been disconnected. This techniqueworks best when the machine is not using a network installation (SETUP /N)of Windows. Issuing the DIR command may restore the network connection andallow the application to continue or at least exit without causing thesystem to stop responding (hang).

You can also try to close all open files and attempt to quit Windows. Ifthe problem results from a network installation of Windows having lost itsnetwork connections, you will get a message telling you that you do nothave enough memory to complete the operation.

Avoiding the Problem

The following steps may help prevent this problem:

  • Increase FILES= to 128 or higher in the CONFIG.SYS file.
  • Increase FCBS= to 25 or higher in the CONFIG.SYS file.
  • Increase Sessions= to 20 or higher in the PROTOCOL.INI file.
  • Set NCBS= to 40 in the PROTOCOL.INI file.
  • Set NetHeapSize= to 52 in the [386Enh] section of the SYSTEM.INI file.
  • Set TimerCriticalSection= to 5000 or higher in the [386Enh] section of the SYSTEM.INI file.
  • If you are using a network installation of Windows (Setup /N) set maintainserverlist= to NO in the [network] section of the SYSTEM.INI file.
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Article ID: 90226 - Last Review: 09/17/1999 12:51:00 - Revision: 1.0

Microsoft Windows for Workgroups 3.2

  • KB90226