Time Capsule & Xbox 360 over ethernet issues

Question

I have a Time Capsule connected to my modem, I can access the internet over WiFi on my mac without issues, however when I connect my Xbox 360 to the router via ethernet it will not allow me to connect to Xbox live. What's highly frustrating is that it passes all test apart from the ICMP one. According to some forums, if your receive this then your router is not compatible with xbox live. However this contradicts people being able to connect through their TC on other posts. I can connect to xbox live if I directly plug it into my modem, so it is not anything todo with that side of things.
Is there any reason why this might be on my TC and how might I go about sorting this problem out?
Any help much appreciated
Matt

Answer 1

Although I also haven't been able to get it working over Wi-Fi yet, I've got it working pretty happily over what is ostensibly ethernet (powerline networking ftw).
My guess is that the problem you're having is due to your Time Capsule ignoring stuff (as a security measure) that Xbox Live is sending the Xbox, so what I think you need to do is tell your Time Capsule to stop doing that for the Xbox. You do that by getting your Time Capsule to give the Xbox the same IP address every time it connects, and to not block anything sent to that IP address.
First we need to get the Xbox's MAC address, which you can find either on the back of the Xbox itself, or by going to the System blade on the Xbox Dashboard, selecting Network Settings, Edit Settings, Additional Settings (push the left thumbstick to the right), Advanced Settings, then the MAC address should be displayed.
Just to be clear, a MAC address has nothing to do with Apple's computers, standing for Media Access Control, and is a quasi-unique code that nearly every network adapter has. We're using it here so your Time Capsule can recognise the Xbox.
Now you've got the MAC address, open AirPort Utility, select your Time Capsule and click Manual Settings, the Internet toolbar icon, then the DHCP tab. Click the plus button under the DHCP Reservations box, type Xbox 360 (or whatever you want) as the description, and click Continue. Now type the Xbox's MAC address into the MAC Address box, then click the IPv4 box, change the last number from 2 to 35 (so it's something like 10.0.1.35), and click Done.
Now we have the Xbox getting the same IP from the Time Capsule, we need to tell the Time Capsule to stop filtering stuff that's sent to that IP, to do that, click the NAT tab (inside the Internet section), then "Enable default host at:" and enter 35 as the last two digits (so it matches up with the IP address we put in the IPv4 box earlier). Finally, click Update, and when your Time Capsule has finished restarting, try the connection test on the Xbox again.