Hello,
I was wondering if someone faced similar issues in the past.
We learned about Audio broadcast calls where no voice was transmitted. And it turned out that the ECMP multicast load splitting had to be added under global config mode at the LHR level, connected BGP ECMP upwards, as shown below:
As described in Cisco Doc:
If Router 5 and Router 2 are inconsistently configured with the ip multicast multipath command, or if Router 5 is a third-party router:
Then Router 2 and Router 5 may choose different RPF neighbors for some (*, G) or (S, G) states.
For example, Router 2 could choose Router 3 for a particular (S, G) state or Router 5 could choose Router 4 for a particular (S, G) state. In this scenario, Router 3 and Router 4 would both start to forward traffic for that state onto Ethernet interface 1, see each other's forwarded traffic, and—to avoid traffic duplication—start the assert process. As a result, for that (S, G) state, the router with the higher IP address for Ethernet interface 1 would forward the traffic. However, both Router 2 and Router 5 would be tracking the winner of the assert election and would send their PIM joins for that state to this assert winner, even if this assert winner is not the same router as the one that they calculated in their RPF selection. For PIM-SM and PIM-SSM, therefore, the operation of ECMP multicast load splitting can only be guaranteed when all downstream routers on a LAN are consistently configured Cisco routers.
Any sharing of experience with ECMP multicast load splitting in MCAST environments is much appreciated.
