Hi, my friend is organising a lan party with 8 people across 2 Xbox Ones. Just wondering what I need to know before going into it. Do I simply connect the two Xbox’s with an ethernet cable and we’re all good? Or is there more to it? I had a google and found mixed messages. Thought you guys could help give some clarity. Thanks.
You have come to the right place 
The short answer is:
- If you use a normal home internet “Router / Wireless Router / Gateway” to connect the consoles together to do a LAN, the consoles will get IP addresses from the router, and LAN will work out of the box, no extra configuration required. - If you use a “Ethernet switch / Gigabit Switch / Switch / Hub” or directly connect the consoles with an ethernet cable, then the consoles will not receive IP addresses automatically, and you will have to go to each console to manually assign an IP address (and each consoles IP needs to be unique.)I made a thread and YouTube video with instructions on how to manually assign IP addresses (specifically in the case of directly connecting two consoles).
Thread: Halo MCC “System Link” LAN setup tutorial video
YouTube video: Halo MCC “System Link” LAN tutorial (Direct connect two consoles with ethernet)