Xbox 360 can't connect to internet; MTU error

Recently, my 360 began encountering an MTU error when connecting to the internet. After numerous attempts to correct the issue, it still fails to connect. I'll provide the details of my setup, as well as my attempts to correct the issue below.

What country/state/province do you live in: Australia/WA
Modem brand & model number: Netgear; DG834G v5.
Router brand & model number: Netgear; DG834G v5 (It's a modem router) .
If Wireless, are you using a white or black external adapter, or an internal (Xbox 360S) adapter? Internal adapter.
Is UPnP enabled: Yes
Things you have tried:
I have attempted to set the MTU of my router to the lowest possible value within the 360 compatible range, and a few other values besides. The 360 compatible range is between 1364 and 1492. Previously, my MTU was set at 1492, which is on edge of the range, but still acceptable. I have never before tampered with my MTU; this was the default value, and for the 3 or so years that I've had the Xbox 360, it's worked fine, until now. For no discernible reason, my 360 began encountering this issue; I did not make any changes to any settings in my router prior to the emergence of this issue, and no other individual within the household has the know-how to tinker with router settings, so the issue seemingly emerged out of nowhere. I changed the MTU of my router to 1364 and 1365; both failed to rectify the issue. UPnP has always been enabled on my router, so that has nothing to do with it (Xbox live worked fine until recently). I have already opened up all ports required for Xbox live; I opened UDP 88, UDP/TCP 3074 and UDP/TCP 53, I did this long ago, when I ran into P2P connectivity issues with my 360, and it resolved them. Lastly, I had, for a lengthy while, set my Xbox 360 to a static IP by setting the values for IP, gateway, subnet mask and DNS (primary and secondary) manually on the system, and then setting a static IP on my router. This resolved some issues that I had connecting to Xbox live a while back, and until now, I had no issues; everything worked smoothly. As I stated, no changes have been made to trigger this issue, and there are no MTU issues, as my MTU is within the acceptable range, yet I still can't connect, and receive an MTU error. Lastly, it should be mentioned that my connection tests always fail during the internet phase, not the xbox live phase. This is why I'm surprised. Normally, most people receive the MTU error when the test fails during the final (Xbox live) phase, but mine fails during the internet phase. Always. My attempts to fix the issue have been futile, and I am at my wits end. If someone could assist me with this, I would be most grateful.


Question Info

Last updated August 9, 2018 Views 3 Applies to: