Breh, that ip blocking shyt is entirely relative to what kind of router you have. I doubt we have the same router, but so I can't give you step by step instructions.
Xbox NAT Type | Xbox 360 NAT Type | Xbox NAT Error - Xbox.com
Maybe that will help you.
Go to step 4. Find out what your ipaddress is (that's how you access your router) and then google how to set up ip address blocking.
I didn't apply that Youtube fix from my router either, I just did it on my desktop from the cmd prompt that was posted.
thanks, ill attempt this for the 360
any fix for the PS3?