In the discussion of Figure 21.1, three alternatives for transmitting a packet to a multicast address were discussed: broadcast, multiple unicast, and true multicast. Yet another alternative is flooding. The source transmits one packet to each neighboring router. Each router, when it receives a packet, retransmits the packet on all outgoing interfaces except the one on which the packet is received. Each packet is labeled with a unique identifier so that a router does not flood the same packet more than once.

Fill out a matrix similar to those of Table