Microsoft KB Archive/814622

= Remote Procedure Call Datagram Runtime Component Leaks Firewall Ports on the Client Side =

Article ID: 814622

Article Last Modified on 2/20/2007

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APPLIES TO


 * Microsoft Windows 2000 Professional Edition
 * Microsoft Windows 2000 Server
 * Microsoft Windows 2000 Advanced Server

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SYMPTOMS
When you use a program that performs many of the Cluster Application Programming Interface (API) OpenCluster and CloseCluster function calls in quick succession, the program may run out of resources and stop responding (hang).



CAUSE
This problem may occur after you limit the port usage on the firewall that the program uses to communicate. When you use the Cluster API, the CloseCluster function frees the resources that are used by OpenCluster, including Remote Procedure Call (RPC) ports. However, on some unsuccessful RPC communications or unsuccessful memory allocations, the RPC datagram runtime component releases the firewall port, causing it to be unrecoverable for the life of the running process. These &quot;leaked&quot; ports may cause the program to exhaust its resources.



Service Pack Information
To resolve this problem, obtain the latest service pack for Microsoft Windows 2000. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

260910 How to Obtain the Latest Windows 2000 Service Pack

Hotfix Information
A supported fix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Apply it only to computers that are experiencing this specific problem. This fix may receive additional testing. Therefore, if you are not severely affected by this problem, Microsoft recommends that you wait for the next Windows 2000 service pack that contains this hotfix.

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 about support costs, visit the following Microsoft Web site:

http://support.microsoft.com/contactus/?ws=support

NOTE: In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The typical support costs will apply to additional support questions and issues that do not qualify for the specific update in question.

The Global version of this fix has the file attributes (or later) that are listed in the following table. The dates and times for these files are listed in coordinated universal time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.

  Date         Time   Version           Size     File name -  18-Mar-2003  21:33  5.0.2195.6662     944,400  Ole32.dll 18-Mar-2003 21:26  5.0.2195.6662     432,400  Rpcrt4.dll 18-Mar-2003 21:33  5.0.2195.6662     187,664  Rpcss.dll



WORKAROUND
You may be able to work around this problem by increase the number amount of ports available to RPC. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

814622 Remote Procedure Call Datagram Runtime Component Leaks Firewall Ports on the Client Side



STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article. This problem was first corrected in Microsoft Windows 2000 Service Pack 4.



MORE INFORMATION
For additional information about how to obtain a hotfix for Windows 2000 Datacenter Server, click the article number below to view the article in the Microsoft Knowledge Base:

265173 The Datacenter Program and Windows 2000 Datacenter Server Product

The RPC ports that are used by OpenCluster are recycled after a timeout period after calling the CloseCluster function. By default, that period is 240 seconds. However, the port remains allocated from the list of available firewall ports that are maintained by the Microsoft Remote Procedure Call Service (Rpcss.exe). RPCSS maintains the list of all the available firewall ports. When the client program has to establish a new connection to the server, it creates a new socket, and then asks RPCSS for the port to use. This is necessary because each datagram RPC client is also an RPC server, because it has to service Conv_Callbacks from the server. The firewall port remains allocated to the process for the lifetime of the process. Because of this, if the client later closes the original connection and requests a new connection to be opened, it allocates a new firewall port from RPCSS, even if it has already allocated ports in the past that it no longer uses. This is a known design limitation of firewall ports. They remain allocated to the process for the lifetime of that process.

Keywords: kbhotfixserver kbqfe kbnetwork kbwin2ksp4fix kbprb kbwin2000presp4fix kbfix kbbug KB814622

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