XCON: Dynamic RAS Connector Not Sending Over NetBeui

• Microsoft Exchange Server, version 4.0

SYMPTOMS

The Microsoft Exchange Dynamic RAS Connector might fail to deliver mail over NetBeui even though the modem connection is established and NetBeui has been installed on both Microsoft Exchange Server computer's Windows NT RAS configuration settings.

CAUSE

By default, the Microsoft Exchange Message Transfer Agent (MTA) only supports the use of Microsoft TCP/IP, IPX/SPX compatible transport, and Banyan Vines IP.

RESOLUTION

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.

To enable support for NetBeui over the Dynamic RAS Connector, the following registry adjustment will need to be made on both Microsoft Exchange Server computers.

1. Start Regedt32.exe and open the following key:

         HKEY_LOCAL_MACHINE\Software\Microsoft\Exchange\Exchange Provider
   

2. On the RPC_SVR_BINDING_ORDER registry entry add the following value:

         NCACN_NB_NB
   

It is important to note that the MTA reads the RPC_SVR_BINDING_ORDER in a serial manner, so the placement of the protocols can effect how the MTA functions. If the NCACN_NB_NB value is first in the order, the MTA will attempt to use NetBeui first. If it is last, the MTA will read through all the other values sequentially. What this means is that if NetBeui and TCP/IP are both loaded, and the NCACN_NB_NB value is last in the binding order, TCP/IP will be used. This is only important in environments where there are mixed protocols and/or adapters.

CAUTION: Using only the NetBeui protocol with the Microsoft Exchange Dynamic RAS Connector may cause delays in modem disconnect times with certain modems and/or telco line conditions. This is due to a limitation in the NetBeui protocol. If such symptoms are encountered, we recommend that an additional protocol such as TCP/IP also be installed.