Any computer with an Internet connect uses a special IP address and port number. The IP address and port number is what allows your computer to communicate with other computers over the Internet. Should you ever need to look up what address or port number you're using--if you call your Internet connection's customer service techs, they will ask for you IP address and port number--there is a simple and quick to find them whether you're using a PC or a Mac.
Click on your computer's "Start" button, located at the left-hand side of the screen. For Vista users, this will just be the Windows icon at the bottom of your screen.
Double-click on "My Network Place." This is on the left-hand side of the Start Menu's screen.
Click "Properties." The select either "Local Area Connection" or "Wireless Network Connection." Only select Wireless Network Connection if you're using a wireless connection to access the Internet.
Select "Support > Details." Your IP address and port number will appear in a new window.
Select "System Preferences" from the bottom of your computer screen. If you don't see the gears icon, select "Finder > Macintosh HD > System Preferences."
Select "Network" from under the Internet and Wireless category.
Select "AirPort" or "Ethernet" depending if you use wireless connection or an Ethernet. Your IP address/port number will be displayed on the right-side of the AirPort or Ethernet screen.