Re: The MSComm Error 8021 with desc.: "Application-defined or object-defined error"

From: Randy Birch (rgb_removethis_at_mvps.org)
Date: 08/24/04

  • Next message: Rino Ouellet: "Re: The MSComm Error 8021 with desc.: "Application-defined or object-defined error"" 
    Date: Tue, 24 Aug 2004 17:49:32 -0400

    Since you appear not to be positive that the comm control is causing the
    error, here's another wild-ass guess that may explain why your user
    experinces a failure but you don't.

          Multihomed Master Browser May Cause Event ID 8021 and 8032

    Q135404

    --------------------------------------------------------------------------------

    The information in this article applies to:

      a.. Microsoft Windows NT Workstation versions 3.5, 3.51, 4.0
      b.. Microsoft Windows NT Server versions 3.5, 3.51, 4.0
      c.. Microsoft Windows 2000 Advanced Server
      d.. Microsoft Windows 2000 Server
      e.. Microsoft Windows 2000 Professional

    --------------------------------------------------------------------------------

    SYMPTOMS
    Your computer running Microsoft Windows NT or Windows 2000 may occasionally
    log one or more of the following events in the Event Viewer System log:
      Event id: 8021
      Source: Browser
      Description: The browser was unable to retrieve a list of servers from the
    browser master <PDC> on the network \device\<protocol_netcard>. The data is
    the error code.
      -or-
      Event id: 8032
      Source: Browser
      Description: The browser service has failed to retrieve the backup list
    too many times on transport of <protocol_netcard>. The backup browser is
    stopping.
    This symptom occurs if:

      a.. Your computer is a multihomed computer (that is, it may link
    simultaneously to two or more subnets using multiple network cards).

      b.. Your computer is a master browser.

      c.. Your computer is running the TCP/IP protocol.

    CAUSE
    The following situations can cause this symptom:

      a.. Your computer network cards are linked to the same subnet.

      b.. Your computer network cards are not linked directly to the same
    subnet, but are linked indirectly through other subnets that they are
    connected to.

      c.. The master browser is using an incorrect subnet mask.

    WORKAROUND
    To work around this problem, do one of the following:

      a.. Unbind all but one of the TCP/IP subnet transport bindings from the
    workstation service.

      -or-

      b.. Remove all but one of the network cards or RAS connections.

      -or-

      c.. At the command prompt type the following command:
        net stop browser
      NOTE: This option prevents you from receiving computer browse lists from
    other networks.

    After you perform these steps, wait at least 10 minutes to see if the errors
    still occur. If they do, continue troubleshooting by cross- referencing 2
    pieces of information. First, check the transport that failed in the event
    log. For example, error 8021 displays a message similar to the following:
      The browser was unable to retrieve a list of servers from the browser
    master \\<server_name> on the network \Device\NetBT_<driver_name>. The data
    is the error code.
    The important data is NetBT_<driver_name>, which indicates the protocol and
    netcard binding, also known as an "endpoint." The potential protocols you
    may see are:
      Nbf_netcard = NetBEUI NetBT_netcard = TCP/IP (or NetBIOS over TCP/IP)
    NwlnkIpx = IPX/SPX (NwLink) [will not indicate netcard] NwlnkNB = NetBIOS
    over NwLink [will not indicate netcard]
    After you have determined the failed protocol endpoint, check the working
    status of the Browser service on all installed protocols with the Windows NT
    resource kit program Browstat.exe. At a command prompt, type the following
    command:
      browstat status
    This will enumerate the browser status on all endpoints. Look for the
    message Browser is NOT active on domain under each endpoint. Disregard data
    about endpoints that list "NdisWanX" (such as Device\NetBT_NdisWan5); these
    are RAS endpoints and will usually list the error anyway.

    You should find a protocol match between these two steps. The next step is
    to record any important information about the protocol from Protocol Setup
    in the Network tool in Control Panel. Then, remove the protocol, restart the
    computer, and see if the error no longer gets logged (remember to wait at
    least 10 minutes). Then, try reinstalling the protocol, checking for the
    error, and reapplying the service pack that exists on the current Windows NT
    installation.

    If the error persists after a protocol reinstallation, you may have problems
    with the network adapter card. Check with the vendor to see if there is an
    updated driver, or try another network adapter card.

    STATUS
    Microsoft has confirmed this to be a problem in the Microsoft products that
    are listed at the beginning of this article. We are researching this problem
    and will post new information here in the Microsoft Knowledge Base as it
    becomes available.

    Additional query words: tcpip multi-homed multi homed

    Keywords : kbnetwork
    Issue type : kbbug
    Technology : kbWinNTsearch kbWinNTWsearch kbWinNTW400 kbWinNTW400search
    kbWinNT351xsearch kbWinNT350xsearch kbWinNT400xsearch kbWinNTW350
    kbWinNTW350xsearch kbWinNTW351xsearch kbWinNTW351 kbwin2000AdvServ
    kbwin2000AdvServSearch kbwin2000Serv kbWinNTSsearch kbWinNTS400xsearch
    kbWinNTS400 kbWinNTS351 kbWinNTS350 kbwin2000ServSearch kbwin2000Search
    kbwin2000ProSearch kbwin2000Pro kbWinNTS351xsearch kbWinNTS350xsearch
    kbWinAdvServSearch

          Last Reviewed: February 12, 2001
          © 2001 Microsoft Corporation. All rights reserved. Terms of Use.

    --------------------------------------------------------------------------------

    Send feedback to MSDN.Look here for MSDN Online resources. 

    -- 
Randy Birch
MVP Visual Basic
http://vbnet.mvps.org/
Please respond only to the newsgroups so all can benefit.
"Rino Ouellet" <rinouellotravail@globetrotter.net> wrote in message 
news:wNNWc.51986$X12.24140@edtnps84...
: Hello.
:
: Can someone tell me the possible causes of the error I have?
:
: I have the error 8021 (Application-defined or object-defined error) in a 
Sub
: that contains the line
:
:    FrmMain.MSComm1.Output = (Q$)
:
: where Q$ is a string we send on Com1. It contains some other lines, but it
: only assign a variable to the value 5 and set an Image visible and another
: image invisible.
:
: In the current circumstance, I suppose the error 8021 is caused by MSComm
: control. The description of the error 8021 for MSComm control is "Internal
: error retrieving device control block for the port".
:
: So what could be the causes of this "Internal error retrieving device
: control block for the port"?
:
: Note: The error happens on our client's computer but we can't reproduce 
the
: trouble on our computer and it seems to work properly here. I use Visual
: Basic 6.0.
:
: Thank you!
:
: -- 
:
: My E-mail: rinouellotravail@globetrotter.net
:
:
  • Next message: Rino Ouellet: "Re: The MSComm Error 8021 with desc.: "Application-defined or object-defined error""

    Relevant Pages