XCON: Configuring MTA TCP/IP Port # for X.400 and RPC Listens

ID: Q161931

The information in this article applies to:

Microsoft Exchange Server, version 4.0 Service Pack 4
Microsoft Exchange Server, version 5.0

SUMMARY

The Microsoft Exchange Message Transfer Agent (MTA) in versions Microsoft Exchange Server 4.0 Service Pack 4 (SP4) and 5.0 contains two new features that allow the MTA to be configured to use different TCP/IP port numbers for X.400 connectors and for RPC listens.

MORE INFORMATION

By default, the Microsoft Exchange MTA will use TCP/IP port 102 to communicate with other X.400 MTAs. For example, if two Microsoft Exchange Sites are connected by an X.400 Connector with a TCP/IP MTA Stack, both MTAs will communicate over port 102 by default. However, this port number is now configurable with the addition of the following registry value:


   RFC1006 Port Number

This case-sensitive registry value is a DWORD and does not exist by Default. To add the registry value:

WARNING: Using Registry Editor incorrectly can cause serious, system-wide problems that may require you to reinstall Windows NT to correct them. Microsoft cannot guarantee that any problems resulting from the use of Registry Editor can be solved. Use this tool at your own risk.

Run the Registry Editor(Regedt32.exe).

Under the HKEY_LOCAL_MACHINE subtree, go to the following subkey:


      \SYSTEM\CurrentControlSet\Services\MSExchangeMTA\Parameters

Add the following case-sensitive DWORD value:
```
      RFC1006 Port Number 
```

Quit Registry Editor.

If the "RFC1006 Port Number" registry value does not exist in the registry, the Microsoft Exchange MTA will assume a value of 102 for this setting and thus will expect all X.400 MTA communication to occur over port 102 when using a TCP/IP MTA stack. All MTAs that communicate with each other over X.400 need to use the same TCP/IP port number.

The other additional registry setting allows the MTA to be configured to listen to remote procedure calls (RPC) on a specific port number. It is not necessary for all Microsoft Exchange MTAs to be configured to listen for RPC communication on the same port. RPC communication relies on the End-Point Mapper to relay the appropriate port number so that further communication can then be directly achieved by going directly to the port number that the End-Point Mapper reported for a specific server. This behavior can be examined by using a network sniffer such as Network Monitor to monitor the RPC communication between two MTAs.

The following registry value determines what TCP/IP port a given MTA will use to listen for RPC communication:


   TCP/IP port for RPC listens

This case-sensitive registry value is a DWORD and does not exist by default. To add the registry value:

WARNING: Using Registry Editor incorrectly can cause serious, system-wide problems that may require you to reinstall Windows NT to correct them. Microsoft cannot guarantee that any problems resulting from the use of Registry Editor can be solved. Use this tool at your own risk. but can be added using regedt32 to the following registry key:

Run the Registry Editor(Regedt32.exe).

Under the HKEY_LOCAL_MACHINE subtree, go to the following subkey:


      SYSTEM\CurrentControlSet\Services\MSExchangeMTA\Parameters

Add the case-sensitive registry value below. This is a DWORD:
```
      TCP/IP port for RPC listens 
```

Quit Registry Editor.

The MTA does not read either of these two registry values dynamically. Therefore, once a change has been made to one of these registry settings, the MTA must be stopped and restarted before the change will go into effect.

For more information about the ramifications and guidelines for static port assignment of Exchange services, please see the following article in the Microsoft Knowledge Base:

Q180795 XADM: Intrasite Directory Replication Fails with Error 1720

These two new features are available in Microsoft Exchange Version 4.0 Service Pack 4 (SP4) and in Microsoft Exchange Version 5.0.

Additional query words: firewall


Keywords          : kbbug4.00 kbbug5.00 kbfix4.00.sp4 XCON 
Version           : :4.0; winnt:5.0
Platform          : winnt 
Issue type        : kbbug

Last Reviewed: April 10, 1999