A wireless network interface device receives a packet, wherein the packet includes (i) a set of one or more flag bits, and (ii) a medium access control (MAC) header, and the MAC header contains at least (i) a first address field specifying a receiver address, and (ii) a second address field specifying a transmitter address. The wireless network interface device processes the packet to determine whether the packet is a multicast packet. When it is determined that the packet is a multicast packet, the wireless network interface device processes a third address field in the MAC header to determine a MAC multicast address for the packet.