I had successfully configured my MBP to share internet with my Xbox 360 under snow leopard. After installing lion, without making any settings changes, it no longer works. I was even able to configure another MBP still running Snow Leopard with the exact same settings as on my Lion computer, and it still works. The problem is from Lion. Here are my wifi settings: Here are my ethernet settings: Here are my internet sharing settings. I have also tried "Airport" rather than "Wifi", that doesn't work either: My wifi router is at 192.168.1.1 My Xbox 360 has the following configuration: IP: 10.0.0.2 Subnet Mask: 255.255.255.0 Gateway: 10.0.0.1 Primary DNS Server: 192.168.1.1 Secondary DNS Server: 220.127.116.11 (Google DNS) What do I do?