Unicast— One-to-one routing.
Broadcast— Sent to destination 255.255.255.255; used to transmit from one to everyone.
Multicast— Sent to a destination in the 224/4 range, used to transmit from one to a group.
|2.||Broadcasts are not forwarded by a router by default.|
|3.||A router does not forward these packets by default unless some form of multicast routing is enabled.|
|4.||A Layer 2 switch cannot learn the location of the destination multicast address, so the packets are flooded to all ports on the destination VLAN by default.|
|5.||The first four bits of a multicast IP address are 1110.|
|6.||The host must receive and examine every frame that has the MAC address it is interested in, regardless of for which of the IP addresses the frame is destined. The host then looks at the destination IP address in the packet header to verify that the more specific IP multicast address is a desired multicast group. If not, the packet is discarded.|
|9.||Scalability—bandwidth used by multicasted content does not increase with the number of receivers.|
|10.||Multicasting is efficient in terms of end-system processing because it allows network cards to throw away traffic based on destination MAC.|