IP Address Help

I connect to the internet using a cable modem through Cox.Net. I am having troubles writing a simple client/server program that connects my computer to a friend's computer using winsock.dll. I realized that my ip address as shown to me through ipconfig is different than what is shown to me through whatismyip.com. I have used both of the ip's given and I still cannot connect. Can anyone give me a few pointers? ## Deliverables Some advice on what to do and if you're bored or overly generous maybe a sample project using winsock. ## Platform windows xp