IP Multicast trying to set Rendezvous point

[Noble]

Hello,

I have a fairly simple environment that requires IP multicast routing to do paging through CUCM. 

I am using PIM-SM, and require the RP to be set to two routers in HSRP.  Is it possible to use the 'ip pim rp-address' command and point it to the HSRP virtual IP of the router interface, or is there some other way?

The router log is receiving  %PIM-6-INVALID_RP_JOIN for invalid RP %VIP_Address%, so I'm not sure if Routing,multicasit's even accepting this?

I am not very familiar with multicast, so any help appreciated.

Thanks,

[Georg Pauwen]

Hello,

you need to configure HSRP aware PIM, which basically means creating standby groups. Below is an example:

interface GigabitEthernet 0/0
ip address 192.168.1.1 255.255.255.0
ip pim redundancy HSRP_1 dr-priority 60
standby 1 ip 192.168.1.3
standby 1 timers 5 15
standby 1 priority 120
standby 1 name HSRP_1

Check this document for reference:

https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/ipmulti_pim/configuration/15-e/imc-pim-15-e-book/imc_hsrp_aware.pdf

[Noble]

Thanks, would this configuration allow me to specify the RP on other routers using the standby IP?

ie: ip pim rp-address 192.168.1.3

[Georg Pauwen]

Hello,

exactly. RP address is the standby address.

[Noble]

For some reason it doesn't work when I use the standby address.  When I remove it and put the address of an individual device it works and is able to pass traffic.  Is it possible I am missing something?

Thanks for your help.

[Georg Pauwen]

Hello,

can you post the configs of the routers ?

[Noble]

Attached is the topology.

R1/R2 is the HSRP pair that should act as the RP.

There is a L3 switch (Nexus) behind this pair that connects to the multicast source. 

All L3 interfaces/SVI's are participating via:

     ip pim sparse-mode

     (on all interfaces)

Here is the configuration on the interface I am attempting to create the RP peering to:

interface GigabitEthernet0/0/2
  ip address 10.150.250.1 255.255.255.0
  ip pim redundancy HSRP12 hsrp dr-priority 60
  ip pim sparse-mode
  standby 12 ip 10.150.250.3
  standby 12 priority 255
  standby 12 preempt
  standby 12 name HSRP12
  ip ospf 1 area 0
  negotiation auto

I've added the RP-address command to all devices as per below:

  ip pim rp-address 10.150.250.3

It does not work with this setting, however if I set it to the individual device address, it works.  (ie. ip pim rp-address 10.150.250.1)

Note: the Nexus switch is responsible for intervlan routing, so I've had to configure the pim commands on the virtual interfaces.  I'm not sure if the Nexus is the route of the problem - I was able to get it to work only one way initially, as in, I switched the source and receiver (per the diagram) and it worked.  However, when I configured it as per the diagram it did not work until I specified the RP-address.

Thanks.

[Georg Pauwen]

Hello,

I tested this in GNS3, with one HSRP and no Nexus. You have another HSRP between R3 and R4 ? Can you post the full configs of all devices involved ?

That said, is the HSRP working ?

[Harold Ritter]

You should be considering Anycast RP for this kind of design.

Regards,