Viewing the PIM multicast forwarding table
Also you can check the multicast forwarding table showing the ingress and egress ports of the multicast stream.
FGT-3 # get router info multicast table
IP Multicast Routing Table
Flags: I - Immediate Stat, T - Timed Stat, F - Forwarder installed
Timers: Uptime/Stat Expiry
Interface State: Interface (TTL threshold)
(10.166.0.11, 239.255.255.1), uptime 04:02:55, stat expires 00:02:25
Owner PIM-SM, Flags: TF
Incoming interface: port2
Outgoing interface list:
port3 (TTL threshold 1)