Multicasting is the process of sending a message to multiple clients at the same time. Each client will receive the same message. In order to participate in this process, clients need to join a multicast group. When a message is sent, its destination address indicates that it is a multicast message. The multicast groups are dynamic with clients entering and leaving the group at any time.
Multicast is the old IPv4 CLASS D space and uses addresses
220.127.116.11. The IPv4 Multicast Address Space Registry lists multicast address assignments and is found at http://www.iana.org/assignments/multicast-addresses/multicast-addresses.xml. The Host Extensions for IP Multicasting document is found at http://tools.ietf.org/html/rfc1112 ...