Routeros - IGMP PIM Multicast issue

RouterOS General
1

Hello

I’ve setup IGMP/PIM between two CRS354 devices. All i want to do is setup a local multicast network between multiple dummy devices acting as switches via bridge, but not flood the multicast. i have it all setup and it works for the most part. The only issue i have is the secondary device will still flood all multicast feeds from transmit sources on its ports back to main device. It doesn’t flood local ports or ports on main, just the connection between devices. The mains source multicast also do NOT flood over the connection to the secondary device, just the other way, secondary to main. Hoping its just a setting i’m missing. i’ve followed all the mikrotk pim examples as well.

thanks

2

Based on this description, this sounds like correct behavior based on IGMP. Your primary device would then be the querier - it needs all the streams so it can distribute it to other downstream switches or even its own ports.

What’s the real problem? Traffic is flowing where you don’t expect? Is that link full now? Some other issue? Depending, you might be able to change the architecture.

3

i see what you are saying. i may be thinking about the Igmp workflow wrong. So all source multicast feeds on separate switches will always flood back to the main pim rp router, correct? not necessarily flooding all the main pim router ports, but the connection port from switches that have source multicast. I would just need to make sure the link to the main pim has enough bandwidth to support the multicast bandwidth. is that correct?

thanks

4

So all source multicast feeds on separate switches will always flood back to the main pim rp router, correct?

Yes, sometimes called the mrouter port - which connects upstream to a multicast management system.

Here is a reasonable overview: https://reaper81.wordpress.com/tag/mrouter/

It’s based on Cisco, but the ideas are the same.

5

Thank you for the info, will take a look.

One more question.
what are the proper settings for the bridge ports for the following?
unknown unicast flood (default checked)
unknown multicast flood (default checked)
unknown broadcast flood(default checked)
Trusted(unchecked)