Editing Teredo tunneling (section)

{{Short description|Protocol transition technology in computer networking}}
{{IPv6 transition mechanisms}}

In [[computer network]]ing, '''Teredo''' is a [[Microsoft]] [[IPv6 transition mechanisms|transition technology]] that gives full [[IPv6]] connectivity for IPv6-capable hosts that are on the [[IPv4]] [[Internet]] but have no native connection to an IPv6 network. Unlike similar protocols such as [[6to4]], it can perform its function even from behind [[network address translation]] (NAT) devices such as home routers. 

Teredo operates using a [[platform independent]] [[tunneling protocol]] that provides [[IPv6]] (Internet Protocol version 6) connectivity by [[encapsulation (networking)|encapsulating]] IPv6 [[datagram]] packets within IPv4 [[User Datagram Protocol]] (UDP) packets. Teredo routes these datagrams on the [[IPv4 Internet]] and through NAT devices. Teredo nodes elsewhere on the IPv6 network (called '''Teredo relays''') receive the packets, un-encapsulate them, and pass them on.

Teredo is a temporary measure. In the long term, all IPv6 hosts should use native IPv6 connectivity. Teredo should be disabled when native IPv6 connectivity becomes available.  [[Christian Huitema]] developed Teredo at [[Microsoft]], and the [[IETF]] standardized it as RFC 4380. The Teredo server listens on [[User Datagram Protocol|UDP]] port [[Well-known ports|3544]].