Xbox need add an option to change the MTU

The required MTU for every xbox console the same, have you connected your old console to the network recently to see if the MTU error comes up on that console as well? The aministrator of your internet may have changed the MTU in order to let the students
who need the bandwidth for their studies access the internet easier.

3

Unplug the power cables from your modem and make sure the Xbox 360 console is turned off. Unplug your router from the modem. Connect one end of the Ethernet cable into the port on the modem and the other end into the Xbox 360 console. Turn your modem back
on.

4

Turn your Xbox 360 on and sign onto Xbox Live. If this procedure doesn’t help, manually change the MTU settings through the router.

5

Consult the router instruction manual on how to alter MTU settings. Change your MTU settings to 1364 if the router supports an MTU settings feature. If the router does not support a manual MTU settings feature, you will need to contact your Internet service
provider.

Read more: How to Fix the MTU Setting on a XBox | eHow.com
www.ehow.com/how_6160347_fix-mtu-setting-xbox.html

If you use ADSL your max MTU you can use is 1492 not 1500. If you have an option for auto MTU use ist if not set it to 1492 or 1478. Don´t forget to restart your Router after the change.

it didnt work. it's just that i need to change the MTU settings on the router and i have no access to it

MTU is the packet size your network can handle.

What type of Modem do you have? What´s your connection type?

Cable Internet or (A)DSL?

Is there an option on your Modem to change MTU? YOUR ISP should tell you what MTU you can use.

DSL Connections uses 1492

Cable Internet uses 1500 (not possible with DSL)

Is on your Modem an option for ping respond? I read about that sometimes if you don´t allow wan ping respond the network can´t detect your MTU. This could be a Problem.