The role of multicast addresses

IP multicast addresses, or host Group addresses, are marked by Class d ip addresses. The maximum four bits of class d ip addresses are "1110", which ranges from 224.0.0.0 to 239.255.255.255.
224.0.0.1-All multicast-enabled hosts in the CIDR Block (communication between hosts)
224.0.0.2-All vrouters supporting multicast in the CIDR Block (used for inter-route Communication)
224.0.0.4-All DVMRP routers in the CIDR Block
224.0.0.5-All OSPF routers (OSPF sends HELLO packets)
224.0.0.6-All OSPF router (ospf dr)
224.0.0.9-All r00002 routers (Multicast Of r00002)
224.0.0.13-All PIM Routers
CGMP host and host Multicast
Multicast between IGMP routers and Routers