In one embodiment, a method comprises identifying a fat tree network topology comprising top-of-fabric (ToF) switching devices, an intermediate layer of intermediate switching devices connected to each of the ToF switching devices, and a layer of leaf network devices; and causing a first leaf network device to initiate establishment of first and second redundant multicast trees for multicasting of data packets, including: causing first and second ToF switching devices to operate as roots of the first and second multicast trees according to first and second attribute types, respectively, causing the first leaf network device to select first and second of the intermediate switching devices as first and second flooding relays belonging to the first and second attribute types, respectively, and causing the first and second flooding relays to limit propagation of registration messages generated by the first leaf network device to the first and second ToF switching devices, respectively.