* Martin List-Petersen <martin@airwire.ie>
Your best bet: set up a Terredo gateway and facilitate these Xboxes as long as you don't give them native IPv6.
This is unlikely to help, as the XB1 doesn't use Teredo relays at all. The XB1 uses Teredo to facilitate direct p2p communication between IPv4 consoles only. Essentially it is used an IPv4 NAT traversal mechanism. Its Teredo implementation does not allow communication between IPv4 and IPv6 peers. This is the only communication pattern which would normally require a third-party Teredo relay. This unfortunately also means that provisioning IPv6 is also unlikely to help, unless you're in a position to provision it to both peers. See: https://www.ietf.org/proceedings/88/slides/slides-88-v6ops-0.pdf Personally I'd start out by verifying the connectivity to and functionality of Microsoft's Teredo servers, which are used for NAT address discovery and port mapping during tunnel setup (unlike Teredo relays, Teredo servers aren't part of the Teredo «forwarding plane»). Tore