Boeing Research & Technology This document specifies the operation of IP over tunnel virtual links using Asymmetric Extended Route Optimization (AERO). Nodes attached to AERO links can exchange packets via trusted intermediate routers that provide forwarding services to reach off-link destinations and route optimization services for improved performance. AERO provides an IPv6 link-local address format that supports operation of the IPv6 Neighbor Discovery (ND) protocol and links ND to IP forwarding. Dynamic link selection, mobility management, quality of service (QoS) signaling and route optimization are naturally supported through dynamic neighbor cache updates, while IPv6 Prefix Delegation (PD) is supported by network services such as the Dynamic Host Configuration Protocol for IPv6 (DHCPv6). AERO is a widely-applicable tunneling solution especially well-suited to aviation services, mobile Virtual Private Networks (VPNs) and other applications as described in this document.