A software defined networking (SDN) controller or routers in a network determine unicast paths from an ingress router to egress routers from the network based on quality-of-service (QoS) metrics for links between routers of the network. A subset of the unicast paths is associated with a multicast flow based on one or more QoS criteria for the multicast flow. A router pushes a label stack onto a packet of the multicast flow. The label stack includes labels that identify the subset of the unicast paths. The packet including the label stack is multicast through the network to the egress routers. Routers that receive the multicast packet selectively modify the label stack in the packet based on the labels that identify the subset of the unicast paths. The routers selectively forward the packet based on the labels.