The Lmhosts file resolves IP addresses with domain names. When setting up for RAS connectivity, you need to add the IP address and domain of each Microsoft Exchange Server computer to the Lmhosts file on the RAS server.
If the Lmhosts file already exists, it will be located in the Winnt40\System32\Drivers\Etc directory. If this file does not exist, you need to create it. If you are not familiar with Lmhosts files, you should review the Lmhosts.sam file provided with Windows NT. This sample file is also located in the Winnt40\System32\Drivers\Etc directory.
To work with the Lmhosts file, you must first enable Lmhosts lookup functionality.
You must edit the Lmhosts file to include the server names and IP addresses for each Microsoft Exchange Server computer that you plan to connect using the Dynamic RAS Connector.
The file should include the server name and the IP address of the NIC from the opposing Microsoft Exchange Server computers. The LMHOSTS entry should be followed by a #PRE entry, and a #DOM:<domain name> entry if the server specified is a primary domain controller (PDC) or a backup domain controller (BDC) responsible for validating logons. For example, the Lmhosts file for each of three Microsoft Exchange Server computers connected through a Dynamic RAS Connector would contain the following lines:
When working with Lmhosts files, you should do the following:
You can verify that the contents of the Lmhosts file can be interpreted by Windows NT using the Nbtstat command.
Complete the following steps to verify the Lmhosts file.
The Microsoft Exchange Server computer names entered when generating the Lmhosts file should be displayed in the cache. If not, the Lmhosts file or Windows NT is not correctly configured.