Huawei Technologies Dusseldorf This document describes Enhanced Dual Stack (EDS), a host-side framework intended to reduce the operational risk and workload of IPv6 deployment. Today, many applications select IPv6 or IPv4 using static address- selection rules. These rules provide a useful baseline, but they are not live measurements of current reachability or performance. If IPv6 is selected when it is broken or degraded, users may experience failures or delays. This creates a need for extensive upfront IPv6 validation before deployment. Happy Eyeballs (HE) reduces this risk for applications that implement it, but it does not automatically help existing applications that continue to use traditional APIs such as getaddrinfo(), socket(), and connect(). EDS aims to make IPv6/IPv4 selection performance-informed for both new and existing applications. It does this through three enhancements: