IP Multicast is defined in RFC 1112/2236(IGMPv2).
Ip Multicast can send traffic to a single address and does not care about the receiving hosts. Only one destination address is needed and all hosts listening to the stream or host that have registred can receive the datastream. It does support dynamic meberships to groups. So clients can themselfes register for the stream.
One multicast address can carry multiple streams. It uses UDP as transport protocol.
Address range:
Class D 224.0.0.0 – 239.255.255.255
The range from 224.0.0.0 to 224.0.0.255 is reserved for routing protocols and other types of protocols.
Static Addresses (local scope):
- 224.0.0.1 all hosts on a subnet
- 224.0.0.2 all routers on a subnet
- 224.0.0.4 Distance Vector Multicast Routing Protocols (DVMRP)
- 224.0.0.5 OSPF routers
- 224.0.0.6 OSPF designated routers
- 224.0.0.9 RIP Version 2 routers
- 224.0.0.10 EIGRP
- 224.0.0.13 Protocol independent Multicast (PIM)
Global scope addresses:
224.0.1.0 – 238.255.255.255
Administratively scoped:
239.0.0.0 – 239.255.255.255
Internet Multicast address range reserved by IANA (lower 23 bits):
0100.5e00.000 – 0100.5e7f.ffffAll Multicast addresses use the 01.00.5e in their multicast address.
Source:
http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/ipmulti.htm#xtocid1