Do two routers need to be PIM neighbors in order for them to exchange auto-rp 224.0.1.39 and 224.0.1.40 packets?

[Sam Brynes]

Just wondering if a PIM neighborship is required for the two PIM routers to process auto-RP packets.

[balaji.bandi · Accepted solution]

Yes, you need a PIM configuration for the Auto-RP to Work. not sure what devices you have environment. 

Follow the below link to set up and read the guidelines :

https://www.cisco.com/c/en/us/td/docs/ios/solutions_docs/ip_multicast/White_papers/rps.html

[Sam Brynes]

Thanks Balaji. You mean the "ip pim <sparse / dense / sparse-dense>" command? And I'm assuming you'll also need the "ip multicast-routing" command? Do you also need to enable IGMP as well?

[balaji.bandi]

ip multicast-routing   <<-- this is must have for your multicast to work
ip pim sparse-dense-mode  << - enable PIM 

IGMP based  on your dequirement join and leave yes.

old post I have provided URL has all the information - did you get a chance to look? ( hope that help some clarify for your understand and requirement)

https://www.cisco.com/c/en/us/td/docs/ios/solutions_docs/ip_multicast/White_papers/rps.html#wp1036139