We propose a new protocol to achieve fault recovery of multicast applications in IP internetwork with mobile participators. Our protocol uses the basic unicast routing capability of IETF Mobile IP as the foundation, and leverages existing IP multicast models to provide reliable multicast services for mobile hosts as well. We believe that the resulting scheme is simple, scalable, transparent, and independent of the underlying multicast routing facility. A key feature of our protocol is the use of multicast forwarding agent (MFA) to address the scalability and reliability issues in the reliable mobile multicast applications. Our simulation results show the distinct performance advantages of our protocol using MFAs over two other approaches proposed for the mobile multicast service, namely Mobile Multicast Protocol (MoM) and bi-directional tunneling, particularly as the number of mobile group members and home agents (HAs) increases.