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Q259240: XWEB: Configure OWA to Connect to Exchange Through a Firewall

Article: Q259240
Product(s): Microsoft Exchange
Version(s): 5.5
Operating System(s): 
Keyword(s): 
Last Modified: 06-AUG-2002

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The information in this article applies to:

- Microsoft Outlook Web Access, version 5.5 
- Microsoft Exchange Server, version 5.5 
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IMPORTANT: This article contains information about modifying the registry. Before you 
modify the registry, make sure to back it up and make sure that you understand how to restore 
the registry if a problem occurs. For information about how to back up, restore, and edit the 
registry, click the following article number to view the article in the Microsoft Knowledge Base:

  Q256986 Description of the Microsoft Windows Registry

SUMMARY
=======

This article describes how to set up Microsoft Outlook Web Access (OWA) to
connect to Microsoft Exchange Server through a firewall. This configuration
assumes that there is a firewall between OWA and the Exchange Server computer.
There are three ports that need to be opened on the firewall in this
configuration. On the Exchange Server computer, two ports need to be statically
mapped. To do this, the ports must be opened by editing the registry.

NOTE: The third port, port 135, must be opened on the firewall.

MORE INFORMATION
================

Follow the steps in this section to statically map the two ports on the Exchange
Server computer. The Exchange Server computer that OWA points to must have these
ports mapped.

NOTE: One port must be mapped for the information store, and one port must be
mapped for the directory.

For additional information about configuring Exchange Server services for
Internet firewalls, click the article number below to view the article in the
Microsoft Knowledge Base:

  Q155831 XADM: Setting TCP/IP for Exchange and Outlook Client Connects Through
  a Firewall

WARNING: If you use Registry Editor incorrectly, you may cause serious problems
that may require you to reinstall your operating system. Microsoft cannot
guarantee that you can solve problems that result from using Registry Editor
incorrectly. Use Registry Editor at your own risk.

1. Start Registry Editor (Regedt32.exe).

2. Locate the following key in the registry:

  HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MSExchangeDS\Parameters

3. Add the following entry for the Microsoft Exchange Directory service:

  Entry: TCP/IP port
  Type: REG_DWORD
  Data: <port number to assign>

  NOTE: Do not assign ports immediately above the 1023 range. This may cause
  other problems on the Exchange Server.

  For example:

  "TCP/IP Port"=dword:000004C9(1225)

4. Locate the following key in the registry:

  HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MSExchangeIS\ParametersSystem

5. Add the following entry for the Exchange Server information store:

  Entry: TCP/IP port
  Type: REG_DWORD
  Data: <port number to assign>

  NOTE: Do not assign ports immediately above the 1023 range. This may cause
  other problems on the Exchange Server computer.

  For example:

  "TCP/IP Port"=dword:000004CA(1226)

6. Quit Registry Editor.

7. Restart your computer for the changes to take effect.

8. On the firewall, open the ports that you assigned to the directory, the
  information store, and port 135 for the endpoint mapper.

  NOTE: For the Exchange Server to communicate back through the firewall to the
  OWA server it is also necessary to have the ephemeral ports 1024 through
  65535 configured for outbound communications from the Exchange server to the
  OWA server. Although you can specify what ports Exchange listens on for RPC
  traffic, you can not specify what RPC ports the OWA application uses for RPC
  communications.

NOTE: The OWA server must also be a member of the domain where the mailboxes
reside. For additional information about how to configure that access, click the
article number below to view the article in the Microsoft Knowledge Base:

  Q179442 How to Configure a Firewall for Domains and Trusts

Additional query words: XMRP

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Keywords          :  
Technology        : kbOutlookSearch kbExchangeSearch kbExchange550 kbZNotKeyword2 kbOWASearch kbOWA550
Version           : :5.5
Issue type        : kbhowto

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