Q167667: SNA Server Rejects LU6.2 BIND over 2nd Connection

Article: Q167667
Product(s): Microsoft SNA Server
Version(s): WINDOWS:3.0,3.0 SP1
Operating System(s): 
Keyword(s): kbnetwork
Last Modified: 13-JUN-2001

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The information in this article applies to:

- Microsoft SNA Server, versions 3.0, 3.0 SP1, on platform(s):
   - the operating system: Microsoft Windows NT 
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SYMPTOMS
========

If SNA Server 3.0 is configured with more than one connection to a remote
system, and that remote system attempts to serially activate an LU6.2 session
using the same Local APPC LU /Remote APPC LU /APPC Mode name combination over
each connection, the BIND over the first connection succeeds, but the BIND over
the second connection is rejected by SNA Server with sense code = 083500xx,
unless the SNA Server service is stopped and started.

SNA Server will log the following event when sending the negative response to the
BIND arriving over the second connection:

  Event ID: 17
  Source: SNA Server
  Description:
  APPC session activation failure: BIND negative response sent

  Sense data = 083500xx (where xx may be any value)

CAUSE
=====

When SNA Server 3.0 accepts an LU6.2 BIND over a connection, the LU/LU/mode
partnership is cached in SNA Server for that connection. After the session ends,
SNA Server then rejects an LU6.2 BIND for this same LU/LU/mode partnership
received over a different connection, because SNA Server already has a
partnership defined over the first connection.

This problem did not exist in SNA Server 2.x, because the SNA Server
Administrator program prevented the configuration of the same LU/LU/mode
partnership over different connections owned by the same server. However, with
SNA Server 3.0, no explicit APPC LU partnerships are defined, so this allows SNA
Server to encounter this condition.

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

With the hotfix applied, SNA Server will accept a BIND for a specific LU/LU/mode
pairing over a connection even after the same LU/LU/mode session had previously
been active over a different connection. Note that SNA Server does not support
concurrent bound sessions using the same LU/LU/mode names over different
connections.

When a BIND arrives for a Mode that is already partnered over another connection,
SNA Server now checks the state of the partnered connection before failing the
BIND. If the other connection is not active, SNA Server now points the
partnership at the new connection (since the remote LU is obviously on this new
connection now). It would continue to reject the BIND if the first connection is
active, since it is definitely not legal to have the partnerships over two
connections active at the same time.

NOTE: With this update applied, a separate problem occurs in SNA Manager; the
APPC LU status information is not displayed properly when the LU-LU session is
established over the alternate connection. This problem is only a cosmetic
issue. This SNA Manager problem will be corrected in a future SNA Server 3.0
service pack.

Additional query words:

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

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