Validation error when attempting to set a Multicast Local Rendezvous Point (RP) IP, when Active/Active High-Availability is configured.

Getting a validation error during commit:

Details Validation Error:

network -> virtual-router -> [vr-name] -> multicast -> rp -> local-rp -> static-rp -> address 'X.X.X.X/X' is not a valid reference 

network -> virtual-router -> [vr-name] -> multicast -> rp -> local-rp -> static-rp -> address is invalid.

• Platform: Any
• PAN-OS: Any
• Multicast and A/A HA configured.

The same interface and IP address is being selected for both "Local Rendezvous Point" under Network> Virtual Routers> [vr-name]> Rendezvous Points Tab, and the Active/Active HA virtual address under Device> High Availability> Active/Active Config> Virtual Address. This will caused a validation error which will prevent the configuration from committing.

In an A/A HA configuration, a "Virtual Address" is an IP address that moves between two firewalls during a failover (floating IP). Because of this, it will cause issues with Multicast routing, since "Local Rendezvous Point (RP)" requires a stable and consistent IP address to maintain multicast communication.

To solve this issue, a loopback interfaces must be used for the Rendezvous Point (RP). Loopbacks are virtual interfaces, meaning they are not dependent on any specific physical interface. Therefore, even if a failover occurs, the loopback IP remains stable and reachable, ensuring consistent multicast operations.