Question about RPF election

[gongya001]

I am labbing Multicast Assertion mechanism.

From https://www.cisco.com/c/en/us/support/docs/ip/ip-multicast/212595-how-well-do-you-know-pim-assert-mechanis.html 

Based on

the highest PIM neighbor behavior

R2 should be elected for  (*,G) , right ?

Why does the doc say "In the topology, R1 is the RPF neighbour towards the RP, hence R3 sends a (*,G) join towards R1." ?

R3#show ip mroute
IP Multicast Routing Table
Outgoing interface flags: H - Hardware switched, A - Assert winner, p - PIM Join
 Timers: Uptime/Expires
 Interface state: Interface, Next-Hop or VCD, State/Mode
(*, 239.1.1.1), 00:00:55/stopped, RP 192.168.0.100, flags: SJC
  Incoming interface: GigabitEthernet1, RPF nbr 192.168.3.1
  Outgoing interface list:
    GigabitEthernet4, Forward/Sparse, 00:00:55/00:02:04

(10.0.0.2, 239.1.1.1), 00:00:52/00:02:07, flags: JT
  Incoming interface: GigabitEthernet1, RPF nbr 192.168.3.2, Mroute
  Outgoing interface list:
    GigabitEthernet4, Forward/Sparse, 00:00:52/00:02:07
I can't duplicate two different RPF neighbors unless I customize the different routes for  source.

thanks !!

[paul driver]

Hello

On r3 Gi2 enabled to receive multicast? If it isnt then that's why R1 GI2 is at present the rpf for the RP

[gongya001]

From that doc, it does not say which interfaces are enabled for multicast, I assume that all of them are enabled pim sparse mode.

Also R3 does not have Gi2, I do not know which interface you mean.

thanks for taking a look at it. !!

[paul driver · Accepted solution]

Hello

apologies typo - R2 Gi2

[gongya001]

thanks !!

seems easy to understand assert for dense mode, but not for Sparse and SSM.