is the receiving host has disappeared then the l3 switch 3 sends a prune leaving request information to the receiving node the receiving node n 3 detects the prune signal by snooping then the receiving node n 3 generates a deletion request command to the sending node not shown the receiving node n 3 notifies the sending node of its own mac address by unicast receiving the deletion request command the sending node prunes the multicast entry table the sending node broadcasts to the receiving node n 3 the information of the updated multicast entry table receiving the updated multicast entry table the receiving node leaves the multicast group next the update of the multicast entry table of this embodiment is described referring to fig9 fig9 shows the sending node n 1 and a flow of the multicast entry table on the ring network of this embodiment in this embodiment a receiving node receives data through a procedure as shown below first the receiving node sends a reception request command to the sending node n 1 1 in fig9 the sending node n 1 receives the reception request command and then updates the multicast entry table 2 then the sending node n 1 broadcasts the updated multicast entry table to each node 3 in this invention a receiving node halts reception of data through a procedure as shown below first the receiving node sends a deletion request command to the sending node n 1 5 in fig9 receiving the deletion request command the sending node n 1 updates the multicast entry table 2 the sending node n 1 then broadcasts the updated multicast entry table to each node 3 each node holds the received multicast entry table 4 with.