AutoRP messages are sent using multicast addresses 224.0.1.39 and 224.0.1.40. AutoRP dynamically determines the rendezvous point (RP) for a multicast group
so that RPs need not be manually configured. The multicast address 224.0.1.39 is used for RPAnnounce messages, which are sent by candidate RPs to advertise
their eligibility to become an RP. The RPAnnounce messages are received by the mapping agent, which maps the candidate RPs to multicast groups. If multiple
routers are advertised as candidate RPs for a multicast group, the router with the highest IP address is used as the RP for that group. The multicast address
224.0.1.40 is used for RPDiscovery messages, which are sent by mapping agents to advertise the authoritative RP for a multicast group.
Protocol Independent Multicast version 1 (PIMv1) messages are sent using multicast address 224.0.0.2. The multicast address 224.0.0.2 is the allrouters address.
The allrouters address is also used by Internet Group Management Protocol (IGMP).
PIMv2 messages are sent using multicast address 224.0.0.13. The multicast address 224.0.0.13 is the allPIMrouters address. This address is used by PIMv2 to
send status messages, such as hello messages, prune messages, and assert messages. The allPIMrouters address is also used to send Bootstrap Router (BSR)
messages. Like AutoRP, the BSR feature dynamically assigns RPs to multicast groups. However, BSR can be used only by PIMv2; it cannot be used by PIMv1.
Other PIMv2 message types include the Register message, the RegisterStop message, and the Join/Prune message.
VRRP are using 224.0.0.18 address. HSRPv2/GLBP are using 224.0.0.102 address.