Microsoft KB Archive/234932

= TN3270 Access Violation When Using Unique Ports for Sessions =

Article ID: 234932

Article Last Modified on 9/22/2005

-

APPLIES TO


 * Microsoft SNA Server 3.0 Service Pack 4
 * Microsoft SNA Server 4.0

-



This article was previously published under Q234932





SYMPTOMS
Attempting to start the TN3270 server may result in an access violation if it has more than fifty TN3270 sessions configured to use unique TCP/IP ports.

If the Windows NT Server running SNA Server is configured with Drwtsn32.exe as the default debugger, a Drwtsn32.log will be generated when the access violation occurs.

The Drwtsn32.log may contains entries similar to one of the following if this problem occurs:

Application exception occurred: App: exe\tn3servr.dbg (pid=) When: @ Exception number: c0000008

[data omitted]

function: RtlRaiseStatus [...] FAULT ->77f88f29 8be5            mov     esp,ebp [...]


 * > Stack Back Trace <*

FramePtr ReturnAd Param#1 Param#2  Param#3  Param#4  Function Name 00efff28 77f6cf15 c0000008 00000000 77f675ad 00098e64 ntdll!RtlRaiseStatus 602012a0 55536021 57c08556 0102840f 15ff0000 60201050 ntdll!RtlpUnWaitCriticalSection

Application exception occurred: App: exe\tn3servr.dbg (pid=) When: @ Exception number: c0000005 (access violation)

[data omitted]

function: RtlpWaitForCriticalSection [...] FAULT ->77f6cc66 ff4010          inc     dword ptr [eax+0x10] [...]


 * > Stack Back Trace <*

FramePtr ReturnAd Param#1 Param#2  Param#3  Param#4  Function Name 00d8fc18 77f67456 00095d54 01017c7e 00095d54 00084ed8 ntdll!RtlpWaitForCriticalSection 00d8ffb8 77f04f2c 00000000 00000002 0000012e 00000000 ntdll!RtlEnterCriticalSection 00d8ffec 00000000 00000000 00000000 00000000 00000000 kernel32!lstrcmpiW 00000000 00000000 00000000 00000000 00000000 00000000 tn3servr!

In addition, the following events may be logged in the Windows NT Application Event Log:

Event ID: 902

Source: TN3270 Server

Description: Logic error in module SocketActivateEvent identified by: CouldNotFindSocket

Event ID: 902

Source: TN3270 Server

Description: Logic error in module SocketAdd identified by: NoFreeSockets



CAUSE
The TN3270 server is not correctly handling the initialization of more than 50 unique TCP/IP ports. This results in the access violations discussed above when starting a TN3270 server configured with Logical Units (LUs) using unique TCP/IP ports.



RESOLUTION
To resolve this problem, obtain the latest service pack for SNA Server version 4.0. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

215838 How to Obtain the Latest SNA Server Version 4.0 Service Pack



STATUS
Microsoft has confirmed that this is a problem in Microsoft SNA Server versions 3.0, 3.0 SP1, 3.0 SP2, 3.0 SP3, 3.0 SP4, 4.0, 4.0 SP1, 4.0 SP2. This problem was first corrected in SNA Server version 4.0 Service Pack 3.



MORE INFORMATION
In addition to correcting the access violations when initializing more than 50 unique TCP/IP ports, the TN3270 server has been updated to listen over a maximum of 1,000 unique TCP/IP ports. Previously, the TN3270 server could listen over a maximum of 64 unique TCP/IP ports.

With this update applied, the TN3270 can be configured to listen over port 23 (the default TN3270 port) plus an additional 999 user-defined ports.

Please refer to the on-line SNA Server Help for more details on how to configure the TN3270 server and its TN3270 LUs to use specific ports other than the default port of 23.

Keywords: kbbug kbfix kbsna400sp3fix kbqfe kbhotfixserver KB234932

-

[mailto:TECHNET@MICROSOFT.COM Send feedback to Microsoft]

© Microsoft Corporation. All rights reserved.