Topic Last Modified: 2007-03-21

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

If the Exchange Server Analyzer finds that the value for HKLM\System\CurrentControlSet\Services\MSExchangeSA\Parameters\TCP/IP 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\TCP/IP NSPI Port.

The most common reason that this value is configured is to enable MAPI clients to connect to an Exchange server that is on the other side of a firewall. This scenario involves opening multiple ports on a firewall to enable Microsoft Office Outlook® 2003 and Outlook 2007 clients to connect using MAPI to an Exchange server, typically over the Internet.

The recommended deployment for using Outlook in MAPI Mode to connect to an Exchange server over the Internet is to use the RPC over HTTP features found in Microsoft Windows Server™ 2003, Exchange Server 2003, Outlook 2003, Exchange Server 2007, Outlook 2007, and Microsoft Windows® XP Professional. MAPI Mode was formerly referred to as "Corporate" or "Workgroup" mode.

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.

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 TCP/IP 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 TCP/IP 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 deploy RPC over HTTP

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

  2. Review "Deploying Outlook Anywhere" (http://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" (http://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" (http://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" (http://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" (http://go.microsoft.com/fwlink/?linkid=3052&kbid=256986).

For more information about statically mapping ports used by Exchange, see the following Knowledge Base article: