Last weekend I was visiting family out-of-town. I brought the Xbox 360 just in case some of us wanted to play. However, I wanted to show some of the arcade games and Netflix, which require live Internet connections. The television was in their living room, a long way from the router in a bedroom. Since I don’t have the wireless adapter for the 360 my only option was to share the wireless via a Mac.

My experience was specific to using an Xbox 360 but these settings will probably work with other devices.

The way it should have worked was to simply connect the Xbox 360 to the ethernet port on the Mac, get the Mac on the wireless network, and then enable Internet Sharing (System Preferences -> Sharing).

Unfortunately, it just wouldn’t work. Setting the 360 to DHCP also did not help.

After searching and testing I learned what I needed to do. I didn’t keep bookmarks so I can’t give credit to a specific person or site though there were many posts where I found this tip referenced.

Basically, the Mac is not automatically setting up the IP address for the ethernet connection, nor is it passing DHCP. You can tell the IP isn’t setup correctly if it begins with 169.

There are a couple of different solutions out there. For example, some recommended making changes to the firewall/ethernet settings to enabled DHCP pass-through. However, for my needs I thought that was unnecessary.

To make this work you’ll need to change network settings on both the Mac and the Xbox 360. Note – if you are using a laptop it’s a good idea to remove these settings before connecting your laptop to another network. If you don’t, you may not be able to access the network/Internet. Worse, you may create an IP conflict that could cause problems with other machines/devices and network administrators.

One other important thing to note is that the Internet Sharing option only seems to work with the subnet (192.168.2.x) shown below. I didn’t take notes while doing this so it’s possible that the Gateway address on the Xbox 360 needs to be set to the Mac’s IP. I’d try the actual gateway first and then try the Mac IP if it doesn’t work.

Mac Network Settings (ethernet only)

IP: 192.168.2.1
Subnet Mask: 255.255.255.0
Gateway: actual gateway (often 192.168.1.1 but not always)

Xbox 360 Network Settings

IP: 192.168.2.2
Subnet Mask: 255.255.255.0
Gateway: actual gateway
DNS: 192.168.2.1 (your preferred DNS may also work)