In this paper, we study multicast protocols for Mobile Ad-Hoc Networks, and specifically OLSR networks. We describe and compare three multicast protocols, namely MOST (Multicast Overlay Spanning Tree), MOLSR (Multicast OLSR) and SMOLSR (Simple Multicast OLSR), with different approaches and properties with respect to scalability. Our approach is simulation-based: through different scenarios and configurations, we evaluate the performance of each protocol in terms of average packet delivery ratio and average packet retransmissions. We interpret the results in terms of key design properties and applicability of the protocols.