From the Site Identities page you can assign the IP address and TCP port number of your server, as well as add or change a host header name to the Web site you are creating or modifying.
The IP Address is set to All Unassigned by default. The IP addresses of all network interface cards (NICs) installed on the server will appear in the list.
The TCP port is set to 80 by default. This default port number is the industry standard and is understood when you type a Web address into a browser, for example, www.yoursite.com. If you change the port number to anything other than 80, for example, 8055, when users type the Web site address, they must also include a colon and the port number, as in www.yoursite.com:8055.
To modify the parameters for Site Identities
Setting General Site Identity Properties
Creating Application Settings