Configuring Multicast DNS and IGMP across VLANs on Unifi

Since I have two VLANS, some things stop working if I am trying to use a device on one network from the other.

As an example, at the moment I have put my Sonos speakers on the IOT VLAN, but i want to be able to control that from my mobile which connects to the normal network.

Multicast DNS is what is needed to make this work. This should be added to the config.gateway.json

{
"service": {
	 "mdns": {
	  "repeater": {
	   "interface": [
	    "eth1",
	    "eth1.20"
	    ]
	   }
	 }
  }
}

This means that mdns traffic from one network, will be repeated to the other.

The next thing I found I also had to enable was IGMP-Proxy. (also added to config.gateway.json)

{
  "service": {
   	"protocols": {
    	"igmp-proxy": {
    		"interface": {
      		"eth1":{
      			"alt-subnet": [
      				"0.0.0.0/0"
      			],
      			"role" : "upstream",
      			"threshold": "1"
      		},
      		"eth1.20":{
      			"alt-subnet": [
      				"0.0.0.0/0"
      			],
      			"role" : "downstream",
      			"threshold": "1"
      		}
    		}
    	}
    }
  }
}