Sonos, Unifi, VLAN and Firewalls.

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Carrying on from a previous post - Unifi & Sonos VLANs. If you are like me and you have your Sonos Devices segregated on an IoT VLAN and the Sonos Controllers (iPhone etc) on a different VLAN then you will probably need to do some firewalling.

A little Background

VLANs are used for many reasons, segregating networks, preventing multicast packets traversing networks, security amongst other reasons. In this case I wanted all my IoT devices on its own network (VLAN) as there are many security risks with IoT devices and the a separate VLAN for my main LAN. With this I wanted to block all communication from IoT_VLAN to Main_VLAN, however I wanted my Main_VLAN to still be able to communicate with some devices on the IoT_VLAN i.e. Sonos Speakers.

So following on from the previous post where we setup the VLANs and IGMP-Proxying, we will now look at the Unifi Firewalls.

Firewalls work on rules and the rules work in descending order, i.e. if data hits the firewall it will check the rules from the top downwards until it finds a matching rule.


In Unifi there are various Rule headings, WAN, LAN and Guest and each has a IN, OUT and LOCAL. For this guide we will be working with LAN IN - the data is coming from the LAN INTO the USG.

Lets create some rules, these will be in order Top to Bottom.

The first rule is created because when the Controller on Main_VLAN creates a connection with the Speaker on IoT_VLAN we want the speaker to be able to talk back to the controller, hence we create a rule to allow established connections but do not allow it to open new connections.

Name - Allow Established
Enabled - On
Rule Applied - Before pre-defined rules
Action - Accept
IPv4 Protocol - All
States - Established and Related
Source - Address group - Any
Destination - Address group - Any

Next Rule is to allow Sonos Speakers to contact Main_VLAN

Name - SONOS_To_Main_VLAN
Enabled - On
Rule Applied - Before predefined rules
Action - Accept
IPv4 Protocol - All
Address Group - Create a group with all the Sonos Speaker IP addresses
Destination - Network - Main_VLAN

Final rule is to block all other data from IoT_VLAN to Main_VLAN

Name - Block IoT_VLAN to Main_VLAN
Enabled - On
Rule Applied - Before predefined rules
Action - Drop
IPv4 protocol - All
Source - Network - IoT_VLAN
Destination - Network - Main_VLAN

And that's it. With these rules devices on IoT_VLAN shouldnt be able to contact devices on Main_VLAN, however Main_VLAN can still contact the Sonos Speakers.

This is what the Rule Page looks like

firewall rule

Unifi Sonos and VLANs

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For the security consious out there you may have split your home network up into VLANs. If you've found this page by searching then you probably already know what a VLAN is and its purpose.

At home I have split my network into 4 VLANs.

VLAN1 - Main data VLAN for all my devices VLAN40 - VLAN for guests to use VLAN60 - Security VLAN, CCTV, alarms etc VLAN80 - IOT devices, internet of things, zwave, zigbee, sonos and home automation etc.

The idea of keeping IOT devices on a seperate VLAN to other devices is mainly for security. Most IOT devices are easily hackable and if this does happen they will only be able to access devices on VLAN80 and not my other devices.

Anyway this post will explain how to get the Sonos devices on VLAN80 to communicate with the controllers (iPhone, iPad, PC) on VLAN1.

With Unifi we need to enable igmp-proxy. To set it we need to SSH onto the USG.

and enter the following commands

edit protocols igmp-proxy
set interface eth1.80 role downstream
set interface eth1.80 threshold 1
set interface eth1.80 alt-subnet
set interface eth1 role upstream
set interface eth1 threshold 1
set interface eth1 alt-subnet

eth1.80 = the VLAN of the sonos devices (IOT) eth1 = VLAN1 the main data VLAN with the Sonos controllers on.

I recommend restarting the igmp-proxy service on the USG. To do so enter the command

restart igmp-proxy

Now it is set, you will have to re-configure the Sonos Device with the controller.

With Unifi, the CLI commands arent persistent with a re-provision. To make the changes stick we need to use a config.gateway.json file

Its location is

C:\users\%username%\Ubiquiti Unifi\data\sites\default\

Edit the config.gateway.json file and enter the below

"protocols": {
        "igmp-proxy": {
            "interface": {
                "eth1": {
                    "role": "upstream",
                    "threshold": "1",
                    "alt-subnet": ""
                "eth1.80": {
                    "role": "downstream",
                    "threshold": "1",
                    "alt-subnet": ""

Obviously changing the VLAN numbers to what ever yours are.

Troubleshooting Ok well this didnt really work straight away for me.

To check that igmp is working you can issue the following commands

show ip multicast mfc


show ip multicast interfaces 

This should show any multicast data its source and where it is going. For example

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On the top half you can see see the source and that some data is going from eth1 to eth1.80. However with the command Show IP multicast interfaces you can see that no multicast data is coming into eth1.80 interface, it seems to be going out on eth1 and into eth1.60. To resolve this I had to issue the restart igmp-proxy command to restart the service. A USG re-provision didnt work.

For creating Firewalls, see this post - Sonos, Unifi, Firewalls & VLANS