This article will guide you on how to set up a static IP address on your Xbox 360®.
On your Xbox 360® Home screen, click on settings and select System.

Step 2:
Select Network Settings.

Select your Wi-Fi name.
Step 4:
Click Configure Network.

Step 5:
Under the Basic Settings, select the second section about your IP Settings.

Step 6:
On the Edit IP Settings screen, select Manual.

Step 7:
Select IP Address.
Step 8:
Enter your static IP address and click on Done.
NOTE: Make sure that the IP address you will assign is within the same network range of your Belkin router. For example, if your router's address is 192.168.2.1, the static IP address you can set will be 192.168.2.x, where x is a value between 2 and 254 and is unused by another device in your network.

You will be prompted back to the previous screen and it will show you the current IP address that you have assigned on the right section.

Step 9:
Select Subnet Mask.
Step 10:
Enter your subnet mask and click on Done.

You will be prompted back to the previous screen and it will show you the current subnet mask that you have assigned on the right section.
Step 11:
Select Gateway.
Enter your gateway address and click on Done.

You will be prompted back to the previous screen and it will show you the current gateway address that you have assigned on the right section.
Step 13:
Select Done at the bottom to save all the changes.

NOTE: The Configure Network screen will appear and it will show the IP settings that you have manually assigned to your Xbox 360®.

Step 14:
Press the B button on your controller to go back to the Network Settings screen. Select Test Xbox LIVE Connection to check your network status.

The test will run and it will check your Network, Internet, and Xbox LIVE connection status. Wait until its done testing.

Once the test is done, you will see your Network, Internet, and Xbox LIVE connection status on the right section.