lispers.net Futurewei This document describes a design for a lightweight decentralized multicast group address allocation protocol (named GAAP and pronounced "gap" as in "mind the gap"). The protocol requires no configuration setup and no centralized services. The protocol runs among group participants which need a unique group address to send and receive multicast packets. Tailored for IPv4 and IPv6 networks, this design offers a simple, lightweight option rather than extending an existing protocol.