If your Xbox 360 loses network/Xbox Live connection after about 30 – 40 minutes of playing, change its network settings to use a static IP address.
I noticed that my Xbox would sign me off XBox Live after about 30-40 minutes of me playing a game. This wasn’t a problem while I was just playing games off my console. But when I started playing against other Xbox Live members or streaming Netflix movie or streaming movies off my PC downstairs, losing the network connection after about 40 minutes started becoming a pain.
I searched around the web and found some people reporting the very same issue but no solution.
After spending some time trying different things, I suddenly realized that when the problem occurs, the IP address of my console gets reset from the dynamically assigned DHCP address of 192.168.0.x to some 169.x.x.x address. I decided to give my console a static IP address and — magic! The problem went away. I can stay connected for hours.
I don’t know if there’s a firmware fix or something to make it work with a dynamic address. At this point, it works and trying to make it work with a DHCP assigned address is just not worth the effort.