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Since I have a Juniper EX2200 performing my layer 3 routing for internal traffic and I have Sonos on a separate subnet than some Sonos clients, I needed to allow multicast across subnets. By creating a loopback interface and using it as my PIM rendezvous point, I was able to get my Windows desktop on (Wired) find my Sonos speaker on (WiFi).

This is pretty much taken directly from the guide here.

First, I leave the default igmp-snooping configuration alone. If yours doesn’t look like this, then you have modified the default configuration:

Then I created a loopback interface to use for multicast:

Next, I added the new loopback interface as passive in my OSPF configuration. The export and the other interfaces were already there for something unrelated to this multicast configuration:

Now I define the IP address of that loopback interface as the rendezvous point and add the necessary VLAN interfaces in sparse mode:

I have subnet on vlan.20 for trusted wired, on vlan.40 for guest wifi, and on vlan.50 for trusted wifi. Since Sonos is on vlan.50, I want all three VLANs to share multicast. You can block multicast from guest wifi to trusted wired via a firewall filter.

Note that because I did not specify a multicast range, the entire range is allowed. Sonos only uses SSDP, orĀ, so if you want to block all other multicasts, you can limit the range with the following:

I hope this helps!