A method for forwarding a multicast data packet, wherein, the method comprising: receiving, by an I/O board of an Virtual eXtensible Local Area Network, VXLAN, switch, a multicast data packet having a VXLAN encapsulation; removing the VXLAN encapsulation from the multicast data packet having the VXLAN encapsulation; determining that layer 3 multicast forwarding is to be performed for the multicast data packet; sending the multicast data packet without the VXLAN encapsulation to a fabric board of the VXLAN switch; receiving, by the fabric board of the VXLAN switch, the multicast data packet sent by the I/O board, determining that layer 3 multicast forwarding is to be performed by the fabric board for the multicast data packet; searching, by the fabric board, a local layer 3 multicast group table for the layer 3 multicast group entry matching with a destination IP address and a destination MAC address of the multicast data packet; when a multicast group member port in the layer 3 multicast group entry corresponding to the multicast data packet is a Virtual Local Area Network, VLAN, port, adding an internal encapsulation to the multicast data packet, and sending the multicast data packet having the internal encapsulation to each I/O board on the VXLAN switch, wherein, the internal encapsulation comprises an index of the layer 3 multicast group entry, and the multicast group member port indicates a port through which a connection to a multicast group member is established; and receiving, by each I/O board on the VXLAN switch, the multicast data packet having the internal encapsulation sent by the fabric board; sending, by the each I/O board on the VXLAN switch, the received multicast data packet to a VLAN according to a layer 3 multicast group entry corresponding to the index in the internal encapsulation; the layer 3 multicast group entry being included in a local layer 3 multicast group table. receiving, by an I/O board of an Virtual eXtensible Local Area Network, VXLAN, switch, a multicast data packet having a VXLAN encapsulation; removing the VXLAN encapsulation from the multicast data packet having the VXLAN encapsulation; determining that layer 3 multicast forwarding is to be performed for the multicast data packet; sending the multicast data packet without the VXLAN encapsulation to a fabric board of the VXLAN switch; receiving, by the fabric board of the VXLAN switch, the multicast data packet sent by the I/O board, determining that layer 3 multicast forwarding is to be performed by the fabric board for the multicast data packet; searching, by the fabric board, a local layer 3 multicast group table for the layer 3 multicast group entry matching with a destination IP address and a destination MAC address of the multicast data packet; when a multicast group member port in the layer 3 multicast group entry corresponding to the multicast data packet is a Virtual Local Area Network, VLAN, port, adding an internal encapsulation to the multicast data packet, and sending the multicast data packet having the internal encapsulation to each I/O board on the VXLAN switch, wherein, the internal encapsulation comprises an index of the layer 3 multicast group entry, and the multicast group member port indicates a port through which a connection to a multicast group member is established; and receiving, by each I/O board on the VXLAN switch, the multicast data packet having the internal encapsulation sent by the fabric board; sending, by the each I/O board on the VXLAN switch, the received multicast data packet to a VLAN according to a layer 3 multicast group entry corresponding to the index in the internal encapsulation; the layer 3 multicast group entry being included in a local layer 3 multicast group table.