XCON: TCP/IP Control Block Shortage Event ID 9156

ID: Q247419

The information in this article applies to:

Microsoft Exchange Server, version 5.5 SP3

SYMPTOMS

After you apply Service Pack 3 for Exchange Server version 5.5, the following error message may be logged in the Windows NT Event Viewer application event log:

Event ID: 9156
Source: MSExchangeMTA
Type: Warning
Category: Resource
Description:
A resource limit has been reached while attempting to open an association. There are no free control blocks available for network type 1.
The configured count is 40. [BASE IL MAIN BASE 1 282] (10)

After this error message is logged, the message transfer agent (MTA) may stop processing messages and you may need to restart the service before mail flows again.

CAUSE

The MTA leaks control blocks. Under stress or slow connection conditions this problem becomes apparent.

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 Exchange Server version 5.5 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:

Component: MTA

File name	Version
Emsmta.exe	5.5.2651.61
P2.xv2	N/A
P42.tpl	N/A
P772.tpl	N/A

For additional information in a related article, click the article number below to view the article in the Microsoft Knowledge Base:

Q229643 XCON: 9156 Errors Occur after Applying Exchange 5.5 Service Pack 2

WORKAROUND

You can use the Evtscan utility from the BackOffice Resource Kit to stop and start the MTA as soon as you detect a 9156 event in the application event log.

STATUS

Microsoft has confirmed this to be a problem in Microsoft Exchange Server version 5.5 Service Pack 3.

Microsoft will use commercially reasonable efforts to address support issues regarding the BackOffice Resource Kit.

Additional query words: bridgehead slow link bork

Keywords : exc55sp3
Version : winnt:5.5 SP3
Platform : winnt
Issue type : kbbug