Reserved IPv6 Interface Identifier for Proxy Mobile IPv6

Proxy Mobile IPv6 (RFC 5213) requires that all mobile access gateways use a fixed link-local address and a fixed link-layer address on any of their access links that they share with mobile nodes. This requirement was intended to ensure that a mobile node does not detect any change with respect to its Layer 3 attachment, even after it roams from one mobile access gateway to another. In the absence of any reserved addresses for this use, coordination across vendors and manual configuration of these addresses on all of the mobility elements in a Proxy Mobile IPv6 domain are required. This document attempts to simplify this operational requirement by making a reservation for special addresses that can be used for this purpose. This document also updates RFC 5213.