All RTR# devices have their interfaces configured with "ip pim sparse-mode", and all RTR# devices have "ip multicast-routing" enabled. Also, OSPF is enabled on all RTR# interfaces in area 0. RTR# devices are OSPF neighbors on their directly connected interfaces.
RTR3's loopback0 interface (220.127.116.11) is configured to be the RP: RTR3 is also the configured mapping agent and an RP candidate:
interface Loopback0 ip address 18.104.22.168 255.255.255.255 ip pim sparse-mode !
ip pim rp-address 22.214.171.124 ip pim send-rp-announce Loopback0 scope 16 ip pim send-rp-discovery Loopback0 scope 16
I did a "show ip pim rp mapping" on RTR1 and expected to see it empty (because all interfaces are configured to be in sparse mode). RTR2 is getting the RP discovery messages sent to 126.96.36.199 from RTR3 since it's directly connected to RTR3, but RTR1 is some how still learning the RP to be 188.8.131.52 from R2. I did a debug ip pim auto-rp on RTR1 to confirm this.
RTR1#sh ip pim rp mapping PIM Group-to-RP Mappings
Group(s) 184.108.40.206/4 RP 220.127.116.11 (?), v2v1 Info source: 18.104.22.168 (?), elected via Auto-RP Uptime: 00:17:49, expires: 00:01:58 RTR1#