PIM DR Redundancy Using HSRP

[RonyD]

Hi to all,

I will dive directly into the problem. I have an existing network that I am using for multicast transmission. The network is based on microwave links and it is using static routes and sub-interfaces (Vlans, with each vlan is dedicated for one multicast source). Now, I have a need to connect another network for redundancy. After I did some research, I found that HSRP will work in my case, considering that both networks (routers) will be connected to the same switch via trunk ports. However, after configuring HSRP and creating multiple HSRP groups for all my multicast sources, I faced a problem with multicast routing. The DR elected is my standby router and I can't configure the DR on my active router because the active router is different in each HSRP group. My question is, how can I separate the 2 networks with each one having its own PIM RP and its own DR, and let the switch do the multicast routing based on the active link? I don't want to use the DR of the standby link for my multicast transmission. Is there a way to configure redundant DR, or to force the active router to be the active DR (per HSRP group) using HSRP?

Thanks!

[Thomas Schmitt]

Apparently HSRP isn't you choice, because your router do not support HSRP aware PIM feature. Cisco documentation says:

HSRP Aware PIM enables multicast traffic to be forwarded through the HSRP active router (AR), allowing PIM to leverage HSRP redundancy, avoid potential duplicate traffic, and enable failover, depending on the HSRP states in the device. The PIM designated router (DR) runs on the same gateway as the HSRP AR and maintains mroute states.

But there are some other concepts for redundant RPs -check phantom RP and anycast RP options.