Digital Equipment Corp This document is a proposal to extend the communications model for IP version 6 (IPv6) to support changing the transport address dynamically between two communicating end systems using a new IPv6 Destination Option. The proposal supports this dynamic address change for both TCP and UDP. The proposal has applicability in IPv6 for Dynamic Renumbering, Anycast Addresses, Multihoming, and Mobility. The proposal requires no changes to the existing TCP or UDP protocols, and is optional for IPv6 implementations.