KnowledgeBase Archive

An Archive of Early Microsoft KnowledgeBase Articles

View on GitHub

Q175336: 3270 User Connects to Host Session of Previous User

Article: Q175336
Product(s): Microsoft SNA Server
Version(s): WINDOWS:2.11,2.11 SP1,2.11 SP2,3.0,3.0 SP1,3.0 SP2
Operating System(s): 
Keyword(s): kbfixlist
Last Modified: 13-JUN-2001

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

- Microsoft SNA Server, versions 2.11, 2.11 SP1, 2.11 SP2, 3.0, 3.0 SP1, 3.0 SP2 
-------------------------------------------------------------------------------


SYMPTOMS
========

When using pooled 3270 LUs with SNA Server, a new 3270 user connects to the host
session of the previous user. This problem was observed when using a CICS host
application, and CICS and VTAM are configured to use the CLSDST and OPTION=PASS
host options.

When CICS issues CLSDST, it saves information about the user id and LU. The
CLSDST=PASS option causes VTAM to drop the current session, put in on queue, and
then start a new session with another VTAM application. When the second session
ends, VTAM takes the session on the queue, and then establishes a session
between the LU and CICS. CICS retrieves the saved information about the user id,
so the users do not need to do a new sign on to RACF.

CAUSE
=====

When SNA Server terminates a 3270 session, SNA Server sends a TERMSELF to the
host, followed by NOTIFY with type 01, which means:

  SLU capability is disabled. Sessions can be Queued but not started.

When a new user activates a 3270 session, SNA Server sends a NOTIFY(type 03 = SLU
Enabled), the old CICS session is started over the LU.

This problem does not occur if SNA Server sends a NOTIFY Type 00, which means

  SLU Capability is Inhibited. Sessions can be Neither Queued nor Started.

STATUS
======

Microsoft has confirmed this to be a problem in SNA Server versions listed at
the beginning of this article.

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

An update to SNA Server 3.0 Service Pack 2 is available from Microsoft which
supports the ability to send a NOTIFY with type = 00 (SLU Inhibited) when a 3270
session is ended. With this update applied, the following registry entry can be
used to activate this behavior:

  HKEY_LOCAL_MACHINE/System/CurrentControlSet/Services/Snaservr
  /parameters/ 

  NotifyInhibited: REG_SZ: YES

Note: This registry parameter is also available in SNA Server 4.0.

For additional information about SNA Server 3270 session termination, please see
the following article in the Microsoft Knowledge Base:

  Q132436 SNA Server Handling of 3270 LU Session Cleanup


Additional query words:

======================================================================
Keywords          :  kbfixlist
Technology        : kbAudDeveloper kbSNAServSearch kbSNAServ300 kbSNAServ211 kbSNAServ211SP1 kbSNAServ211SP2 kbSNAServ300SP1 kbSNAServ300SP2
Version           : WINDOWS:2.11,2.11 SP1,2.11 SP2,3.0,3.0 SP1,3.0 SP2
Issue type        : kbbug
Solution Type     : kbfix

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

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.