This article is not mine. It is from “Da Master Chief” taken from Bungie.net.
Hey Bungie.net Member. Master Chef SC here. Keep the credit to me and you can put this guide anywhere.
This is all about allowing everyone to directly connect to you in games like Halo Reach, so you don’t have to settle for the scraps of Matchmaking. AKA Open NAT. You will not be vulnerable to hackers since you will only be allowing people into programs and games that you select. However, there are some side effects from learning how to get an Open NAT on your computer and xbox:
o - You’ll remove any chance of connection problems with friends
o - You’ll get better pings in all online computer games, because you can connect to everybody and so have more choice in matchmaking.
o - You’ll stream your computer hard drive’s videos, pictures and music onto your Xbox without any stuttering.
o - You’ll maximise the speed of your peer to peer downloading including MSN file transferring
o - You won’t pay an idiot 50 bucks every time something easy goes wrong.
The process is pretty technical but it’ll try to explain it so you can understand it and it will pay back in huge dividends. Face it, you’re living in an age of computers. Know how to -Yoink!- them.
Your Xbox 360’s NAT could already be open without you realising. To check if it is, turn on your Xbox 360 and in the dashboard’s My Xbox area, scroll right all the way to system settings. Select ‘Network Settings.’ Then select ‘Test Xbox Live Connection.’
The Xbox will run a bunch of tests, the last of which is NAT. It could be Strict, Moderate or Open. If it is Open, the test won’t even mention the word NAT. If so, stop reading this guide (either you have a Xbox live certified router or you have your Xbox directly connected to the modem. Please note that some, including my Xbox live certified router don’t do their job of letting xbox live through the firewall). If it reads moderate or strict, then you are ripping yourself off.
To get yourself an open NAT, it’s not quite as simple as ticking a box. That’s why this essay is here. The first thing you have to do is make your Xbox 360’s local IP address ‘static.’ Then you have to open a back door in the router’s software to your Xbox.
If you don’t know what a local IP address is, just think of your home network as a neighbourhood of mostly empty houses, labelled 1 through 255. For the vast majority of neighbourhoods like yours, the mailman lives at house 1 (he is the router) and he’s the only contact with the outside world, which he accesses through the modem. If your computer, Xbox and laptop don’t have a static IP, then they will live in a different house each time they’re turned on and so need to tell the mailman where they live to be in contact with the outside world. If your Xbox or Computer has a static IP, they’re always in the same house.
The second step is to open ports on your router. It’ll make teleporters between the mailman’s house and your Xbox’s. You can see that if the Xbox is always in a different house then the teleporter that goes to house 5 will only work some of time. Further on, each teleporter, or port opened, only works for one certain type of internet traffic AND can only be set to one device, or house.
This number of the houses is the fourth in an “IP Address.” The first three numbers don’t ever change for the whole network. Example: 192.168.1.1 or 10.1.1.1. So change only the last number for different devices on the network, between 1 and 255. Your router will most likely be on 1, but whatever it is on, it will never change.