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) o RFC 5555 (Dual Stack Mobile IPv6) o RFC 5648 (Multiple Care-of Addresses Registration) o RFC 5846 (Binding Revocation) o RFC-to-be (Flow Binding Policy Transport and Flow Binding Policy Format) The MEXT Working Group continues the work of the former MIP6, NEMO, and MONAMI6 Working Groups. The primary goal of MEXT will be to enhance base IPv6 mobility by continuing work on developments that are required for wide-scale deployments and specific deployment scenarios. Additionally, the working group will ensure that any issues identified by implementation and interoperability experience are addressed, and that the base specifications are maintained. The group will also produce informational documentation, such as design rationale documents or description of specific issues within the protocol. The MEXT WG will also explore experimental alternative security mechanisms. The security mechanism specified in the existing standard track RFCs (RFC3775bis, RFC4877) remains the mandatory to implement mechanism that guarantees interoperability between different implementations. The MEXT WG is chartered to deliver one or more experimental alternative mechanisms. All the alternative solutions will be published as experimental RFCs. The working group will also work on operational considerations on setting up Mobile IPv6 networks so that traffic is distributed in an optimal way, for instance by using existing protocol mechanisms to select the closest home agents for new clients. In addition, the working group will bring to completion earlier work on prefix delegation for NEMO, RADIUS support for Mobile IPv6, Mobile IPv6 operation with firewalls, and home agent reliability specifications. Work items related to base specification maintenance include: Create and maintain issue lists that are generated on the basis of implementation and interoperability experience. Address specific issues with specific updates or revisions of the base specification. Currently known specific issues include support for overlapping (private) IPv4 home addresses, negotiation of the protection required for payload traffic, and discovery of the home agent address in IPv4-only networks.