Port conflict: System Attendant HTTP NSPI

[This topic is intended to address a specific issue called out by the Exchange Server Analyzer Tool. You should apply it only to systems that have had the Exchange Server Analyzer Tool run against them and are experiencing that specific issue. The Exchange Server Analyzer Tool, available as a free download, remotely collects configuration data from each server in the topology and automatically analyzes the data. The resulting report details important configuration issues, potential problems, and nondefault product settings. By following these recommendations, you can achieve better performance, scalability, reliability, and uptime. For more information about the tool or to download the latest versions, see "Microsoft Exchange Analyzers" at https://go.microsoft.com/fwlink/?linkid=34707.]  

Topic Last Modified: 2007-01-30

The Microsoft® Exchange Server Analyzer Tool reads the following registry entries to determine whether any port conflicts exist:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MSExchangeSA\Parameters\HTTP Port

HKLM\System\CurrentControlSet\Services\MSExchangeSA\Parameters\Rpc/HTTP NSPI Port

HKLM\System\CurrentControlSet\Services\MSExchangeIS\ParametersSystem\Rpc/HTTP Port

HKLM\System\CurrentControlSet\Services\MSExchangeSA\Parameters\TCP/IP NSPI Port

HKLM\System\CurrentControlSet\Services\MSExchangeSA\Parameters\TCP/IP Port

HKLM\System\CurrentControlSet\Services\MSExchangeSRS\Parameters\TCP/IP

HKLM\System\CurrentControlSet\Services\MSExchangeIS\ParametersSystem\TCP/IP Port

The registry Rpc/HTTP NSPI Port key is used by Exchange to support the Microsoft Office Outlook® 2003 RPC/HTTP and Exchange Server 2007 Outlook Anywhere features. If the Exchange Server Analyzer finds the value for HKLM\System\CurrentControlSet\Services\MSExchangeSA\Parameters\Rpc/HTTP NSPI Port matches any one of the values specified in the other six port registry values listed earlier in this article, an error is displayed. The Exchange Server Analyzer will also display an error for the port that conflicts with HKLM\System\CurrentControlSet\Services\MSExchangeSA\Parameters\ Rpc/HTTP NSPI Port.

To correct this error, you must change the value for this key or the conflicting key as specified by the Exchange Server Analyzer output to a unique value.

If you are supporting RPC/HTTP Outlook 2003 clients or Outlook 2007 you should set the Rpc/HTTP NSPI Port key to the decimal value of 6004. Additionally, you should review the RPC/HTTP configurations in your environment.

Important

This article contains information about editing the registry. Before you edit the registry, make sure you understand how to restore the registry if a problem occurs. For information about how to restore the registry, view the "Restore the Registry" Help topic in Regedit.exe or Regedt32.exe.

To set the Rpc/HTTP NSPI Port registry value

  1. Open a registry editor, such as Regedit.exe or Regedt32.exe.

  2. Navigate to: HKLM\System\CurrentControlSet\Services\MSExchangeSA\Parameters

  3. Double-click the Rpc/HTTP NSPI Port key, and set the Value data field to a unique value that is just above 5000 (decimal).

  4. Close the registry editor.

  5. Restart the computer for this setting to take effect.

To review RPC over HTTP configurations

  1. Review "Exchange Server 2003 RPC over HTTP Deployment Scenarios" (https://go.microsoft.com/fwlink/?linkid=47577).

  2. Review "Deploying Outlook Anywhere" (https://go.microsoft.com/fwlink/?LinkId=80831).

  3. Review the Microsoft Knowledge Base article 833401, "How to configure RPC over HTTP on a single server in Exchange Server 2003" (https://go.microsoft.com/fwlink/?linkid=3052&kbid=833401).

  4. Review the Knowledge Base article 827330, "How to troubleshoot client RPC over HTTP connection issues in Office Outlook 2003" (https://go.microsoft.com/fwlink/?linkid=3052&kbid=827330).

  5. Review the Microsoft Support WebCast, "Using Microsoft Exchange over the Internet (RPC/HTTP) with Microsoft Office Outlook 2003" (https://go.microsoft.com/fwlink/?linkid=3052&kbid=829134).

Before you edit the registry, and for information about how to edit the registry, see the Knowledge Base article 256986, "Description of the Microsoft Windows Registry" (https://go.microsoft.com/fwlink/?linkid=3052&kbid=256986).