XCLN: Error Message When Clients Try To Connect Via Internet

MORE INFORMATION

When it tries to connect to the Microsoft Exchange server over the Internet, the Microsoft Exchange client needs to be able to get the IP address of the Microsoft Exchange server from the Fully Qualified Domain Name (DNS Name) of the Microsoft Exchange Server. This can be achieved through two ways:

• The client has access to a DNS that is aware of the Microsoft Exchange Server.
  
  
• The client computer has a local HOSTS file with an entry for the Microsoft Exchange Server computer.

In most cases, the client will have to have a local HOSTS file, since most DNS's on the Internet will not have information about the Microsoft Exchange Server in their tables.

NOTE: When creating a Microsoft Exchange profile on the client computer, it is possible to enter an IP address as the Microsoft Exchange server name. The RPC TCP/IP runtime routines know how to use a raw TCP/IP address to connect to the server, but the DNS name is what gets stored in the profile. Hence, there must be a DNS entry or local HOSTS file entry for the Microsoft Exchange Server in order for the client to contact the server.

To verify that the client is able to communicate with the server, the following tests could be run:

1. Ping the Microsoft Exchange Server name. This should tell us whether TCP/IP connectivity is available.
   
   If you are able to "Ping" the server, use the RPC Ping utility to test RPC Connectivity with the server. This utility, present in the Microsoft Exchange Server CD in the Support\Rpcping directory, has two components, one to be run on the server and the other to be run on the client computer.
2. If you are able to "Ping" the server, use the RPC Ping utility to test RPC Connectivity with the server. This utility, present in the Microsoft Exchange Server CD in the Support\Rpcping directory, has two components, one to be run on the server and the other to be run on the client computer.

If there are problems with the RPC Connectivity, check to see if the server is located behind a firewall. If a firewall is being used, it will need to configured to allow access to the ports on the Microsoft Exchange Server that are used by Microsoft Exchange. Please refer to the Microsoft Exchange Server Release Notes for more information on "Setting TCP/IP Port Numbers for Internet Firewalls"