Mobile IPv6 specifies routing support which permits an IPv6 host to continue using its home address as it moves around the Internet, enabling continuity of sessions. Mobile IPv6 supports transparency above the IP layer, including maintenance of active transport level sessions. In addition, network mobility (NEMO) mechanisms built on top of Mobile IPv6 allow managing the mobility of an entire network, as it changes its point of attachment to the Internet. The base specifications consist of: o RFC 3775 (Mobile IPv6) o RFC 3963 (NEMO) o RFC 4877 (Mobile IPv6 Operation with IKEv2) The MEXT Working Group continues the work of the former MIP6, NEMO, and MONAMI6 Working Groups. The primary goal of MEXT will be to (A) enhance base IPv6 mobility by continuing work on developments that are required for wide-scale deployments and specific deployment scenarios. Additionally, (B) the working group will ensure that any issues identified by implementation and interoperability experience are addressed, and that the base specifications are maintained. (C) The group will also produce informational documentation, such as design rationale documents or description of specific issues within the protocol. Deployment considerations call for (A.1) solutions to enable dual-stack operation, (A.2) mechanisms to support high-availability home agents, (A.3) allowing the use of multiple interfaces in mobile nodes, (A.4) ways to employ Mobile IPv6 in the presence of firewalls, (A.5) address the specific needs of automotive and aviation communities for route optimisation in network mobility, and (A.6) support for AAA is needed as a continuation of earlier work on bootstrapping. Work items related to large scale deployment include: (A.1) A Solution for Mobile IPv6 and NEMO session continuity for dual stack hosts which attach to IPv4 access networks. Additionally provide a mechanism for carrying IPv4 packets via the Home agent for Mobile IPv6 or NEMO capable dual-stack hosts. (A.2) A protocol based solution for enhancing the reliability of home agents and a method to force a host/router to switch home agents. A mechanism to force an MN to switch the HA that is currently serving it. This is required in deployments where the HA needs to be taken offline for maintenance. (A.3) Use of multiple interfaces. Today, the protocols do not provide suppport for simultaneous differentiated use of multiple access technologies. Several proposals exist for such support, and some of them have been implemented and tested. When a mobile host/router uses multiple network interfaces simultaneously, or when multiple prefixes are available on a single network interface, the mobile host/router would end up with multiple Care-of Addresses (CoAs). In addition, the Home Agent might be attached to multiple network interfaces, or to a single network interface with multiple prefixes, hence resulting in the option to use multiple IP addresses for the Home Agent. This could result in the possibility of using a multitude of bi-directional tunnels between pairs of {Home Agent address, CoA} and a number of associated issues: establishment, selection and modification of multiple simultaneous tunnels. The objective of the WG is to produce a clear problem statement and to produce standard track specifications to the problems associated with the simultaneous use of multiple addresses for either mobile hosts using Mobile IPv6 or mobile routers using NEMO Basic Support and their variants (FMIPv6, HMIPv6, etc). Where the effects of having multiple prefixes on a single interface is identical to the effects of having multiple interfaces each with a single prefix, the WG will consider a generalized approach to cater for multiple prefixes available to a mobile host/router. The WG uses existing tunneling mechanisms defined for Mobile IPv6. The involved nodes need to select which tunnel instance to use when multiple ones are available due to multiple addresses on either end. But the WG does not plan to define a new mechanism for this, but rather document how to use existing mechanisms based upon preferences or policies. In particular, the WG will consider that a tunnel is alive as long as packets can be exchanged with the corresponding peer. In addition, local information, such as interface up/down events, or other failure detection mechanisms can be used to quickly detect failure of tunnel(s).