SNA Server Performance Degrades with Event 631 Errors

ID: Q162491

The information in this article applies to:

Microsoft SNA Server, versions 2.11, 2.11 SP1, 3.0

SYMPTOMS

SNA client response is slow, and at the same time SNA Server or SnaBase reports multiple Event 631 errors (from 10-30 per second) in the Windows NT application event log:

Event: 631
Source: SNA Server (or SnaBase)
Description: Invalid message received across the LAN:
remote: <client IP address:port> msgid 0x0 incorrect or msgtype 1
too high (max 33)

All Event 631 errors are reported from the same client address and client port number.

CAUSE

Event 631 is logged by SNA Server (or SnaBase) whenever it receives an improperly formatted message from an SNA Server client emulator over an existing client TCP/IP socket. The cause of this client behavior is under investigation.

RESOLUTION

An update to SNA Server 2.11 SP1 and SNA Server 3.0 changes the way that invalid client messages are handled. Instead of reporting an Event 631 on each invalid message, this update causes SNA Server (or SnaBase) to:

report a single Event 631 for this client port, and

close the TCP/IP socket to this client.

STATUS

Microsoft has confirmed this to be a problem in SNA Server version 2.11, 2.11 SP1 and 3.0. A supported fix for SNA Server 2.11 SP1 and 3.0 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.

Additional query words: prodsna

Keywords : kbnetwork kbbug3.00 kbbug2.11 kbbug2.11.sp1 kbfix2.11.sp2 snaip
Version : WINDOWS:2.11,2.11 SP1,3.0
Platform : WINDOWS
Issue type :