As the staff obviously know, the forum is now full of these posts all related to the same fault, even if they are worded differently. The issue seems to have started around the last 7-10 days, possibly due to a firmware update?
Running tests on the Xbox returns strict or unavailable Nat types and also "unable to obtain teredo IP address." People are unable to join parties and chat to friends online. They may or may not be able to play a game online but when we can play a game online it usually leads to heavy lag or eventually being kicked out.
Personally, I have tried everything. Static IPS with DMZ enabled or ports forwarded. After going down every troubleshooting road imaginable nothing worked. Xbox support suggest an issue with the router. The only thing that has worked for me was to go and purchase another router for the time being and use the superhub in modem mode. As I did not want to go to great expense this router does not have the same performance of the superhub (when it actually works) so can Virgin Media staff give us an update on the fault? What is the issue and is it being looked into? There are no known faults in my area. I do not want to buy a good router at my expense when I pay for a service that should have capable equipment provided.
I dont know if this is area related or something, there have been a few posts with the same issue. Traditionally you get that error when the wrong MAC address has been allocated to the IPV6 tunnel.
As IPV6 is completely encapsulated when its transmitting/receiving its a bit of a head scratch-er as to what is failing. It SHOULD be either failed NATTING (which should be fixed by port forwarding) or as above in which case clearing down the alternate MAC should fix it.
Do me a favor, pm me a link to your original thread and any others ones you've been active in with the same issue, and Ill comb the boards as well for any others. Ill put it all together and kick it upstairs to staff, see if we can get some traction on the issue.
Just for the record, and I know its no help, Ive two Xbones sitting LAN side both perfectly well behaved with NO port forwarding (im on HUB3, latest firmware) so it may well be some configuration at the CMTS or elsewhere on VM's network. Ive a line with SH2AC and if I get round to it tonight ill test that to see if I can replicate the issue.
I've honestly done everything I can think of and everything anyone else can think of. Cleared the mac address as well. It was like hitting a brick wall because as you say, should have been sorted with port forwarding or even DMZ. From the information I have and people I have spoken to on and offline, everything seems to point to some sort of issue with the router, but it has only affected me over the course of the past 10 days or so. Enabling modem mode solved the issue but obviously kills all wireless. A cheap ASUS router with the SH in modem mode has got me back online for now.