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AutoRP

All Participating Multicast Routers
ip multicast-routing

either:

Router(config-if)#ip pim sparse-dense mode

OR

Router(config)#ip pim autorp listener
Router(config-if)#ip pim sparse mode

*AutoRP relies on dense mode for RP and Mapping Agent communication, therefore if sparse mode is configured on an interface, then ip pim autorp listener needs to be configured to enable dense mode flooding for 224.0.1.39 and 224.0.1.40

Candidate RP:
Router(config)#ip pim send-rp-announce (interface or ip address)
Router(config)#ip pim rp-announce filter rp-list (access-list unicast) group-list (access-list multicast)


RP Relay Agent:
Router(config)#ip pim send-rp-discovery (interface or ip address)

BSR (utilised PIM v2)
All Participating Multicast Routers, including RP and BSR routers:
Router(config)#ip multicast-routing
Router(config-if)#ip pim sparse-mode

RP and BSR routers only:
Router(config)#ip pim bsr-candidate (interface)
Router(config)#ip pim rp-candidate (interface)

Some Multicast addresses of worth to try and remember, by no means a complete list!

Local Network Control Block:
224.0.0.1 All Systems on this Subnet [RFC1112][JBP]
224.0.0.2 All Routers on this Subnet [JBP]
224.0.0.4 DVMRP Routers [RFC1075][JBP]
224.0.0.5 OSPFIGP OSPFIGP All Routers [RFC2328][JXM1]
224.0.0.6 OSPFIGP OSPFIGP Designated Routers [RFC2328][JXM1]
224.0.0.9 RIP2 Routers [RFC1723][GSM11]
224.0.0.10 IGRP Routers [Farinacci] <<<<< EIGRP aswell.
224.0.0.11 Mobile-Agents [Bill Simpson]
224.0.0.12 DHCP Server / Relay Agent [RFC1884]
224.0.0.13 All PIM Routers [Farinacci]
224.0.0.14 RSVP-ENCAPSULATION [Braden]
224.0.0.15 all-cbt-routers [Ballardie] <<<<<<< Core Base Trees
224.0.0.18 VRRP [RFC3768]
224.0.0.19 IPAllL1ISs [Przygienda] <<<<<<< IS-IS Level 1
224.0.0.20 IPAllL2ISs [Przygienda] <<<<<<< IS-IS Level 2
224.0.0.21 IPAllIntermediate Systems [Przygienda] <<<<<<< IS-IS All
224.0.0.22 IGMP [Deering]
224.0.0.23 GLOBECAST-ID [Scannell]
224.0.0.24 OSPFIGP-TE [RFC4973]
224.0.0.25 router-to-switch [Wu] <<<<<<<<< RGMP
224.0.0.37-224.0.0.68 zeroconfaddr (renew 12/02) [Guttman]
224.0.0.101 cisco-nhap [Bakke]
224.0.0.102 HSRP [Wilson]

Internetwork Control Block:
224.0.1.1 NTP Network Time Protocol [RFC1119][DLM1]
224.0.1.21 DVMRP on MOSPF [John Moy]
224.0.1.39 cisco-rp-announce [Farinacci] <<<<<<< Auto RP
224.0.1.40 cisco-rp-discovery [Farinacci] <<<<<<< Auto RP

The complete list can be found here IANA Multicast Addresses