An I/O board of a VXLAN switch receives a multicast data packet having a VXLAN encapsulation, removes the VXLAN encapsulation, determines that layer 3 multicast forwarding is to be performed for the multicast data packet, and sends the multicast data packet to a fabric board of the VXLAN switch. The fabric board determines that layer 3 multicast forwarding is to be performed by the fabric board for the multicast data packet. When a multicast group member port corresponding to the multicast data packet is a VLAN port, the fabric board sends the multicast data packet to each I/O board on the VXLAN switch. Each I/O board sends the received multicast data packet to a VLAN according to a layer 3 multicast group entry used for forwarding the received multicast data packet. The layer 3 multicast group entry being included in a local layer 3 multicast group table.