Cisco Systems Keio University Mtrace2 is a tool that can be used to discover the path a multicast packet takes to reach one or more receivers. This document describes an enhancement to extend mtrace2 to be able to discover more than one path for a single (S,G) or (*,G) entry and to trace more than one (S,G) or (*,G) entries simultaneously. Changes to the mtrace2 protocol, and behaviors required by multicast routers to support the changes, are specified in this document.