The promise of technology is broadcast in the IP network to send information to "best effort" to form a target group, this target group is called a multicast group, this information needs to send a multi-target host in active host, the source host sends only one copy of data, the destination address is a multicast group address data, so that, all members belonging to the group can receive an original copy of the data sent by the host, this multicast mode, only the real information members will receive required information, other hosts do not receive.
Therefore, the way to solve the duplicate copy of the multicast and bandwidth occupied by duplicate data in the unicast case, but also solve a waste of bandwidth resources in broadcast mode.
Multicast and broadcast differences:
Broadcast: Broadcast refers to the IP subnets within a broadcast packet , all subnets inside the host will receive these packets. Means that the network broadcast to each subnet hosts have delivered a packet,
Whether these hosts willing to receive the packet. Therefore, the use of broadcast is very small, only in the local subnet effective internal, through a router and a network device control broadcast transmission.
Multicast : Multicast realize multipoint network connection between the sender and each recipient. If a sender station to simultaneously transmit the same data to multiple recipients, and only a copy of the same packet. It improves data transfer efficiency and reduce the likelihood of backbone network congestion.
I use rip2 agreement here as example
Rip2 switch protocol used will continue to send a data packet destination address 224.0.0.9
As long as the network will be added to the respective forward and added to the process together
How that join it?
In the network xxxx would need to
be added to the network, so that he would reply and forward
Of course, this is just an example of a network application rip2