Hey all,
After experiencing Teredo qualification issues myself and attempting every fix on the corner of the internet; I finally found and compiled a three-click fix with a fairly high success rate. An earlier version had great success on the Forza community subreddit and I’m hoping that same success will be shared here.
After downloading the batch file, simply run it as an administrator (GitHub source code with comments is included in the link for user safety and trust), wait for it to finish (~10 seconds or so), and you should be good to go. You can verify if it worked by checking the “Xbox Networking” statistics under “Windows Settings > Gaming > Xbox Networking” and confirming that your NAT Type no longer says “Teredo is unable to qualify” and Server Connectivity is no longer set to “Blocked”.
Download: Windows 10 Teredo IPV6 Fix (Req: Teredo.Fix.bat)
Note: Some users might have to run the batch file again whenever their system reboots. This is due to Windows undoing the fix for whatever reason; after some time however, the fix will be permanently applied and you will no longer have to run the batch file.
Hope this resolves most of our community members’ issues with Teredo failing to qualify.