This is really going to sound stupid, but for quite a while I spent a significant amount of time trying to figure out what the Ethernet port on the back of my Xbox was for. Before Xbox Live was released there wasn’t very much information about how an Xbox connected to the net. There are references to Microsoft specific cable and other Microsoft hardware, but no one spelled out what you really need in geek not gamer terms.Here is thee bottom line:
1. The Xbox connects to an Ethernet network the dame way a PC connects.

Here are some options:

Xbox to Xbox Connections
Just hook up a crossover cable and have fun.

Xbox to multiple Xbox(s)
Just hook up a straight through cable from each Xbox to the hub or switch of your choice.

Wireless:
Up to this point you need a PC with Internet connection sharing in the case of a Windows PC, or another PC with some OS that can route between an Ethernet card and a wireless card, or a hardware Bridge. Otherwise there is no direct wireless solution for the Xbox.

IP address considerations:
There are none. This is where a cool Windows2000 technology comes in. Xbox as you may or may not know is based on the Windows2000 kernel. (That isn’t really the right way to say it but I’ve been Linux-ing a lot lately.) One of the key components of that semi-glorious OS is something called APIPA or Automatic Private IP Addressing. (check it out at http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dniph/h... ) Anyway, the two cool features of this are IP addressing, and DHCP support. The IP addresses you might have come across on a local machine that is not connected to a network supporting boot-p or DHCP is that APIPA address. This is an address based on a hash of local device information. If the address is in use then APIPA will normally increment the address by one and repeat until it has a usable address. Name resolution is taken care of by NBNS. If a DHCP server is introduced into the segment, then depending on the configuration, at worst the device (Xbox) will request an address from the DHCP server on boot, or at best, the DHCP sever will reserve the currently in use address by the Xbox and reissue addresses on expiration of the lease.
If a DHCP server is available on boot of the Xbox, then the Xbox just picks up an address like any other client an it is on it’s way.

Now here are a list of questions I do not know but will try to find out soon:

First, how do Xboxi (is that the plural of Xbox or is it Xboxes) know when there are other Xboxes on the network. Especially when there are Xbox aware games loaded on each machine such as NASCAR. Is this an NBNS in conjunction with another broadcast level technology? I don’t know. My observed behavior is that when 2 Xboxes with the same network aware game are on the network together the games themselves enumerate the other players/Xboxes.

Second, how do Windows based PC’s see the Xboxes on the network. Do they register themselves through Wins only or are these Windows2000 machines DNS and possibly AD aware. (And if so does that mean I need to extend my Schema to configure my AD users to access Xbox. Not to mention terminal services, and group policy considerations.. OK I am just kidding, but that would be kind of cool to have an OU configured with Loopback Policy mode for your Xbox machine configuration.)

Third, is APIPA to DHCP conversion dependent on an Xbox reboot or does it happen just on lease expiration. Not to mention what is the lease expiration for an Xbox.

Well that is about it. Just remember that Xbox connects to the network just like a PC. Connect it straight through to a networking device. It picks up address, subnet mask and gateway from DHCP, and the rest is “Nothin’ but net.” As my personal internetworking associate Michael Jordan says.