Article ID: 2445979 - View products that this article applies to.
Consider the following scenario:
This issue occurs because a continuous loop that creates new connections is formed between the Forefront TMG Firewall Service (fweng) driver and an instance of Forefront TMG Firewall Service. Therefore, the FWX_E_IS_BUSY error is logged in the Firewall log after a while, and the instance of Forefront TMG Firewall Service stops responding.
This loop occurs when a connection for a data pump is routed to the same local address that initiated the data pump.
Update informationTo resolve this issue, install the software update that is described in the following Microsoft Knowledge Base (KB) article:
(http://support.microsoft.com/kb/2433623/ )Software Update 2 for Microsoft Forefront Threat Management Gateway (TMG) 2010 Service Pack 1
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:
(http://support.microsoft.com/kb/824684/ )Description of the standard terminology that is used to describe Microsoft software updates