Discovery of chromecast devices (from lan) which are connected to guest

Hey there!

I have created a guest network using this guide:

I have connected all of my chromecast devices (an android tv and couple of nest audio devices) to the guest network for security reasons. I basically don't want google to be able to discover the devices in my main ("lan") network.

When I connect to the guest networks, I see all the chromecase devices.
When I am connected to the main network, I don't see any.

What firewall zone or rule do I have to create to make devices in "lan" discover the chrome cast devices in "guest"?
Tried a bunch of things but couldnt get it to work :frowning:


Found both threads already but I think thats not the setup I am looking for.
Isn't it possible to just forward any traffic from lan to guest but not vice versa with a simple rule?

It's not trivial as network discovery relies on multicast traffic which is restricted to a broadcast domain by default and requires something like smcroute to traverse the router.