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GRE Tunnels between HSRP and non-HSRP Sites for Multicast.

I have a design issue where I have a network (Network A) under construction using HSRP at each node with PIM-SM as the network protocol. A new requirement is to add a new interface to this network such that a different network (Network B) can monitor/supervise Network A. Both networks use encryption hardware, with Network A using a bulk or trunk encryptor and Network B uses an IP encryptor. Network B's encryptor can be configured to accept/particpate in PIM-SM exchanges.

Can GRE tunnels be established between Network A's host router HSRP virtual IP addresses at the multicast sources and Network B's host router actual IP address, allowing A to multi-B and multi-B to A message flow?


Re: GRE Tunnels between HSRP and non-HSRP Sites for Multicast.

If you are trying to figure out if the HSRP virtual interface can be used as a source in a GRE tunnel, the answer is no. I tried it once and it did seem to work but soon it started doing crazy things. I was told then that this is not a recommended setup.

Community Member

Re: GRE Tunnels between HSRP and non-HSRP Sites for Multicast.

Thanks. (Be nice to know what the recommended setup is, though). From what I've been able to determine, I'll need a GRE tunnel+GRE Keepalives to each HSRP actual router in order to failover from the primary HSRP router to the Standby if a casualty occurs. The good point is that I'll always have a path from my primary router to the HSRP-based network. The bad point is that every site on the HSRP-based network will need such doubled-up GRE tunnels.

Again, thanks for the response. Bill

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