APPC/CPI-C Apps Fail After SNA Server Receives UNBIND Type X'0A' (176160)
The information in this article applies to:
- Microsoft SNA Server 2.11
- Microsoft SNA Server 2.11 SP1
- Microsoft SNA Server 2.11 SP2
- Microsoft SNA Server 3.0
- Microsoft SNA Server 3.0 SP1
- Microsoft SNA Server 3.0 SP2
This article was previously published under Q176160 SYMPTOMS
An APPC or CPI-C application may occasionally fail to establish a session
over a particular Local APPC LU/Remote APPC LU/Mode partnership that had
previously been used successfully by the application.
Applications may exhibit different symptoms, depending on how the
application is written. If the application has timeout, the application
will terminate the session after the timeout has been reached. Applications
that do not have a timeout may appear to hang (stop responding) while
waiting for the Allocate call to complete.
SNA Application APPC API and LU 6.2 Message traces will show something
similar to the following when this occurs while using an APPC application:
APPC Application Windows APPC DLL
---------------- ----------------
TP_STARTED ->
Open TP Request -> SNA Server
Open TP RSP OK <- SNA Server
[MC_]ALLOCATE ->
Open LU62 Request -> SNA Server
If the application is not designed to time out, this problem could cause an
APPC application to hang while issuing [MC_]ALLOCATE, or a CPIC application
to hang while issuing CMALLC.
NOTE: These symptoms may also occur for reasons other than these described
in this article, so additional troubleshooting may be required.
CAUSE
If independent LU 6.2 session limits over a particular LU/LU/Mode have not
been completed or have been reset by the partner (that is, Mainframe), SNA
Server will have to renegotiate CNOS. During the renegotiation process, SNA
Server will send a BIND to the host over the SNASVCMG mode for the
requested Local/Remote APPC LUs. If the partner rejects the SNASVCMG mode
BIND with an UNBIND Type x'0A', the SNA Server could unlock the wrong Mode
for CNOS negotiations. This causes subsequent CNOS attempts over the
requested Local/Remote APPC LUs to fail with a Command Race Reject error.
Because CNOS does not complete for the requested Local/Remote APPC LUs,
applications requesting sessions over these Local/Remote APPC LUs fail to
get an active session.
WORKAROUND
When this problem occurs, the SNA Server service will need to be stopped
and restarted to allow applications to get active sessions over the
affected Local/Remote LUs.
STATUS
Microsoft has confirmed this to be a problem in SNA Server versions 2.11,
2.11 Service Pack 1, 2.11 Service Pack 2, 3.0, 3.0 Service Pack 1, and 3.0
Service Pack 2.
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):
A supported fix for SNA Server version 2.11 is now available, but has not
been fully regression tested and should be applied only to systems
experiencing this specific problem. Unless you are severely impacted by
this specific problem, Microsoft recommends that you wait for the next
Service Pack that contains this fix. Contact Microsoft Technical Support
for more information.
Modification Type: | Minor | Last Reviewed: | 9/22/2005 |
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Keywords: | kbHotfixServer kbQFE kbbug kbfix KB176160 |
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