SNA Server May Fail to Reestablish a Session Under Certain Conditions

ID: Q235959

The information in this article applies to:

SYMPTOMS

An attempt to reestablish a disconnected session may fail unless the connection is stopped and restarted.


CAUSE

SNA Server does not correlate Host SSCP responses to the original SSCP request if the response is unexpected.


RESOLUTION

A supported fix that corrects this problem is now available from Microsoft, but it has not been fully regression tested and should be applied only to systems experiencing this specific problem. If you are not severely affected by this specific problem, Microsoft recommends that you wait for the next Microsoft SNA Server version 4.0 service pack that contains this fix.

To resolve this problem immediately, contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information on support costs, please go to the following address on the World Wide Web:

http://www.microsoft.com/support/supportnet/overview/overview.asp
The English version of this fix should have the following file attributes or later:

File name Date Time
Snaservr.exe 03/12/99 9:34 AM
Trcservr.exe 03/12/99 9:34 AM

NOTE: Because of file dependencies, the most recent fix that contains the above files may also contain additional files.

NOTE: If this product was already installed on your computer when you purchased it from the Original Equipment Manufacturer (OEM) and you need this fix, please call the Pay Per Incident number listed on the above Web site. If you contact Microsoft to obtain this fix, and if it is determined that you only require the fix you requested, no fee will be charged. However, if you request additional technical support, and if your no-charge technical support period has expired, or if you are not eligible for standard no-charge technical support, you may be charged a non-refundable fee.

For more information about eligibility for no-charge technical support, see the following article in the Microsoft Knowledge Base:
Q154871 Determining If You Are Eligible for No-Charge Technical Support


STATUS

Microsoft has confirmed this to be a problem in Microsoft SNA Server, versions 4.0, 4.0SP1, 4.0SP2 .


MORE INFORMATION

The symptoms described above can only be seen when the Host is sending an unexpected response.

In the case reported, the message flow looks as follows: 


Host                     SNA Server
===================================
ACTLU RQD       ->

                <-       ACTLU +RSP

                <-       NOTIFY SLU enabled

INITSELF -RSP   ->  
with sense code 0857 0002, SSCP - PLU session not active

NOTIFY +RSP     ->
The message flow shows that the Host is sending an INITSELF -RSP in error, which is unexpected as a Response to a NOTIFY Request. However, SNA Server treats this unexpected Response as a Response to its NOTIFY Request. At this point, the Host and the SNA Server are not synchronized any more as far as this session is concerned.

Additional query words: reconnect hangs correlator sequence 


Keywords          : sna4 sna4sp1 sna4sp2 
Version           : WINDOWS:4.0,4.0 SP1,4.0 SP2
Platform          : WINDOWS 
Issue type        : kbbug

Last Reviewed: July 2, 1999