When 16 concurrent connections have been made from a single IP address to a Windows Storage Server 2003 R2-based computer that is running Server for NFS, no additional connections can be made

Article translations Article translations
Article ID: 916794 - View products that this article applies to.
Important This article contains information about how to modify the registry. Make sure to back up the registry before you modify it. Make sure that you know how to restore the registry if a problem occurs. For more information about how to back up, restore, and modify the registry, click the following article number to view the article in the Microsoft Knowledge Base:
256986 Description of the Microsoft Windows registry
Expand all | Collapse all

SYMPTOMS

When 16 concurrent connections have been made from a single IP address to a Microsoft Windows Storage Server 2003 R2-based computer that is running Server for Network File System (NFS), no additional connections can be made from that IP address.

WORKAROUND

Warning Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. These problems might require that you reinstall your operating system. Microsoft cannot guarantee that these problems can be solved. Modify the registry at your own risk.

To work around this problem, use one of the following methods:
  • Restart the computer.
  • Add a DWORD entry that is named MaxConcurrentConnectionsPerIP to the following registry subkey:
    HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\RpcXdr\Parameters\
    Give this entry any value from 2 through 64.

    Note The default value is 16. Type in a value that reflects the number of simultaneous connections that you want to accept on the server.

    To do this, follow these steps:
    1. Click Start, click Run, type regedit, and then click OK.
    2. Locate and then click the following registry subkey:
      HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\RpcXdr\Parameters\
    3. On the Edit menu, point to New, and then click DWORD Value.
    4. Type MaxConcurrentConnectionsPerIP for the name of the DWORD, and then press ENTER.
    5. Right-click MaxConcurrentConnectionsPerIP, and then click Modify.
    6. Click Decimal, type a value from 2 through 64 in the Value data box, and then click OK.
    7. Exit Registry Editor, and then restart the computer.
After you apply hotfix 958272 to Windows Server 2003 or Windows Server 2008, the maximum value of the MaxConcurrentConnectionsPerIP registry entry will be 8192. Additionally, the maximum value for DefaultConcurrentConnections has been raised to 8192.

For more information, click the following article number to view the article in the Microsoft Knowledge Base:
958272 On a Windows Storage Server 2003 R2-based server that hosts NFS shares, excessive I/O requests may cause a TCPZeroWindow condition, and the NFS connection cannot restart as expected

STATUS

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

Properties

Article ID: 916794 - Last Review: February 6, 2009 - Revision: 2.0
APPLIES TO
  • Microsoft Windows Storage Server 2003 R2 x32 Enterprise
  • Microsoft Windows Storage Server 2003 R2 x64 Enterprise
  • Microsoft Windows Storage Server 2003 R2 x32 Standard
  • Microsoft Windows Storage Server 2003 R2 x64 Standard
Keywords: 
kbqfe kbnofix kbbug kbprb kbexpertiseinter KB916794

Give Feedback

 

Contact us for more help

Contact us for more help
Connect with Answer Desk for expert help.
Get more support from smallbusiness.support.microsoft.com