OP, the first reply is 100% correct.
Suggestions for doing this on your platform....
You need to assign yourself a static IP, but you need to keep in mind that when doing this, you will still need the benefits of DHCP when you are not at home/in the development environment with the Belkin router mentioned.
I would suggest taking advantage of the "Location" settings so When your home, you will retain the static IP you give yourself, and when your away, you dont have to remove the static IP / replace it. This can be edited in the System Prefs > Network > First drop down box.
It would also behoove you to do some reading at portforward.com. They're bound to have a write up for your model router, but the steps and principles are the same no matter what the equipment.
Im assuming that your routers interface is accessible by typing http://192.168.1.1 in your web browser (it will be cohesive with your default gateways address).