The Point-to-Point Protocol (PPP) [1] has been proposed as an access vehicle for public ATM networks. Support for multicast in this environment via either RAS replication, or a adding MARS client side by side with PPP is problematic on several fronts. This document describes how an ATM attached system can act as a MARS proxy on behalf of a PPP client. This solution circumvents many of the associated problems with respect to VC frugality, scalability, and authentication.