Clients and servers communicate through a connection. For a client application to connect to a server application, the server application must be listening for the client connection request.
To establish a connection, Open Client:
Uses DSQUERY environment variable to determine the name of the target server. Use DSQUERY only if the Open Client application does not specify the name of the target server. If specified in both, the DSQUERY and the application, the application designation takes precedence.
Uses the interfaces file to obtain the target server’s address.