I am having an issue getting multicast traffic down to the phone on the bottom of the graphic.
Based on default priority values CORE2 should be the DR for the vl802 segment which means that it should be the one to forward the (*,G) Join. The shared-tree is built correctly up to the RP and then from the RP to the Source the SPT is built correctly. If I go under the vl802 SVI on CORE2 and issue ip igmp join-group 239.0.1.2 to emulate the IP phone group membership, I see state get created as it should with the gi0/1 interface between R1 and CORE2 added to the OIL on R1 for the (*,239.0.1.2).
If I ping from the multicast source to 239.0.1.2 the IP assigned to gi0/1 on CORE2 (172.27.34.10) is seen in the response so it seems as though everything is setup as it should be, but for some reason when the source application (informacast) tries sending a multicast stream to the phone it doesn't work. RPF checks pass and mtrace shows the correct path info.
I notice one weird thing when looking at mroute output:
On R1 I also see the gi0/0 interface between R1 and CORE1 in the OIL for the same (*,239.0.1.2) which shouldn't be there since CORE1 is not the DR on the vl802 segment.
(*, 239.0.1.2), 00:02:43/00:02:50, RP 172.27.96.5, flags: S
Incoming interface: Tunnel1, RPF nbr 172.27.3.1, Mroute
Outgoing interface list:
GigabitEthernet0/0, Forward/Sparse-Dense, 00:01:40/00:02:50
GigabitEthernet0/1, Forward/Sparse-Dense, 00:02:43/00:02:48
If I do a mockup of this topology in my home lab I see only the interface between R1 and CORE2 in the OIL on R1:
(*, 239.0.1.2), 00:01:08/stopped, RP 3.3.3.3, flags: S
Incoming interface: Serial0/0/0.64, RPF nbr 10.1.4.4
Outgoing interface list:
FastEthernet0/1, Forward/Sparse-Dense, 00:01:08/00:03:22