The web server IP address management for multi-homing has been simplified in 4D 6.7. A new pop up menu on the "Web Server I" tab of the Database Properties dialog automatically lists all available IP addresses on the machine. This menu also contains the option ALL (selected by default). When this option is selected, the server answers on all available IP addresses.
If you want the server to respond only to queries sent to a specific IP address, simply select that address in the pop up menu.
For more information see:
Command: Secondary IP Address Support (Web)
Connected: An Internet Encyclopedia - 3.3.4 Local Multihoming
Command: On Web Connection Database Method
Command: On Web Authentication Database Method