Q171942: SNA Windows 95 and Win 3.x Named Pipe Clients Fail to Connect

Article: Q171942
Product(s): Microsoft SNA Server
Version(s): WINDOWS:3.0,3.0 SP1
Operating System(s): 
Keyword(s): kbnetwork
Last Modified: 01-APR-2000

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The information in this article applies to:

- Microsoft SNA Server, versions 3.0, 3.0 SP1 
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SYMPTOMS
========

SNA Server Windows 95 and Windows 3.x named pipe clients may be unable to
connect to an SNA Server computer if the Windows NT domain controller is slow to
authenticate user logon requests.

Looking at a network monitor or sniffer trace, the trace may show the server
responding repeatedly with Server Message Block (SMB) Error 231
(ERROR_PIPE_BUSY) to the client's named pipe open request (that is, SMB Open to
\PIPE\COMNODE, the SNA Server named pipe, or \PIPE\COMNAP, the SnaBase named
pipe).

CAUSE
=====

When SNA Server named pipe clients connect to the SNA Server (or SnaBase
service), the client is authenticated against a Windows NT domain controller.
While this authentication is occurring, the SNA Server has no listens pending on
the server end of the named pipe, causing Windows NT to respond with
ERROR_PIPE_BUSY if other clients attempt to connect to the SNA Server named pipe
during this time period.

The SNA Server Windows NT named pipe client accommodates this condition by
retrying the named pipe open request up to 50 times with 250-millisecond delays
between each request. The SNA Server Windows 95 client retries 50 times with no
delay, and the Windows 3.x client only retries five times.

STATUS
======

Microsoft has confirmed this to be a problem in SNA Server versions 3.0 and 3.0
Service Pack 1 (SP1). This problem was corrected in the latest SNA Server
version 3.0 U.S. Service Pack. For information on obtaining this Service Pack,
query on the following word in the Microsoft Knowledge Base (without the
spaces):

  S E R V P A C K


MORE INFORMATION
================

When the update to the SNA Server 3.0 Windows 95 and Windows 3.x clients is
applied, the client retry behavior is similar to the SNA Server Windows NT
client. The SNA client software should already be upgraded to 3.0 SP1 before
applying this update. This has corrected this problem in SNA Server client
stress testing.

However, if the Windows NT domain controller is very slow to respond to client
authentication requests, the network and Windows NT domain structure should be
investigated, to find ways to improve the speed of the authentication. For
example, if users are connecting to an SNA Server which is separated across a
wide area network from the user's Windows NT domain controller, you should
consider installing a Windows NT domain controller near the SNA Server to
improve responsiveness of user authentication.


Additional query words:

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Keywords          : kbnetwork 
Technology        : kbAudDeveloper kbSNAServSearch kbSNAServ300 kbSNAServ300SP1
Version           : WINDOWS:3.0,3.0 SP1
Issue type        : kbbug
Solution Type     : kbfix

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