A method for implementing multicast in a transparent multi-link interconnection (TRILL) network, device, and system

Example discloses a method, apparatus and system for implementing multicast in a transparent multilink Interconnection (TRILL) network, relates to the field of information exchange, to reduce the number of the TRILL network and a distribution tree pruning present invention. The method comprising: Ingress RB determining a corresponding at least one of the following relationship: a first corresponding relationship between the VLAN and the distribution tree, the corresponding relationship between a second Layer 2 multicast VLAN groups and the distribution tree, the three third VLAN correspondence between the multicast group and the distribution tree, the first VLAN, VLAN second, third VLAN to access the Ingress RB VLAN; Ingress RB through the extended iS-iS protocol will be advertised to the determined correspondence relationship TRILL other RB in the network, so that other RB to distribute trees are pruned according to announcement Ingress RB, the establishment of the distribution tree pruning forwarding.