The basic Multicast Server architecture for layer 3 multicast over ATM has been described in draft-ietf-ion-marsmcs-01.txt. It includes a mechanism for fault tolerance using multiple MCSs. However no support for sharing senders/receivers of a group across multiple MCSs has been provided. This document aims to satisfy this need by involving an enhanced version of the MARS in the load sharing and fault tolerance mechanism. This approach is an improvement over the previous one as it subverts the need for any inter-MCS synchronization mechanisms.