Having an issue on my Xbox one and I get an error code for teredo ip not available. Can seem to figure out how to enable teredo tunneling on my xfinity router settings. I already tried all the port fowarding options and still no resolution to the problem.
DMZ sounds like the best idea, but I also have a couple of settings in mind for troubleshooting:
Restart the gateway.
OP. Here is an article about the potential security risks associated with using the UPnP feature;
An article about using the DMZ feature as well;