A first multihoming network virtualization edge (NVE) configured to receive a first multicast packet sent by a multihomed tenant end system (TES), acquire an ingress port of the first multicast packet and a virtual local area network (VLAN) identifier (ID) of the first multicast packet, acquire a virtual overlay network (VN) ID of the first multicast packet according to the ingress port and the VLAN ID, determine whether the ingress port is a designated forwarder (DF) of the VN ID, encapsulate the first multicast packet with an extended NVO3 header when the ingress port is not the DF of the VN ID, and send the first multicast packet that is encapsulated with the extended NVO3 header to another NVE that includes a second multihoming NVE, where the extended NVO3 header carries the VN ID and a link aggregation group (LAG) ID that corresponds to the ingress port.