Methods and apparatus for source rooted multicast (SRM) are provided. As defined herein, SRM generally refers to associating outgoing interface lists (OILs) in the forwarding entry with the source address instead of the group address and aggregating the resulting multicast forwarding states. In this manner, the amount of forwarding state may be reduced, especially in deployments where many hosts are all running the same application and using the same group. One example method generally includes—for each of a plurality of multicast forwarding states associated with a multicast group, wherein each multicast forwarding state is referenced by a source address representing a multicast source and is associated with an outgoing interface list—associating the outgoing interface list with the source address; and aggregating the two or more of the multicast forwarding states having the outgoing interface lists associated with the source addresses to form one or more aggregated forwarding states.