How do you turn this on as it's required for multiplayer by Xbox gaming on the xbone s supplied by Orcon unfortunately the Fritzbox they use is limited in what you can fiddle with and I can't find any setting to turn on/off IPv6 or Teredo tunneling withing the menus 

I have been here to find out whats what http://support.xbox.com/en-NZ/xbox-one/networking/multiplayer-connection-error-solution?icid=furl_xboxone-teredo

but most of the setting they need me to change can't be done on the Orcon supplied Fritz-box 7490