Was able to set up IOT vlan but google home can't see anything I add to it

So I followed the instructions on on this post and I was able to add my google home nest display, but my google home app can't see it.

If I try to add my google home mini speaker to the IOT VLAN it won't work as the app can't see the speaker on network.

I thought it might be a firewall issue, I did add the IOT network to the list networks covered by wan & lan but I don't know much about it so I'm just throwing things at the wall to see what sticks.

I've never used openwrt before this so I admit to my Ignorance on this so some assistance would be appreciated.

I think you need mdns between subnets for it to be discovered, but not 100% sure, sometimes its better to check the type of traffic with tcpdump, but normally they do use mdns.

This will not be super easy since most of it needs to be done via the command line or winscp.

What you want is to install a plugin named avahi-dbus-daemon.

When done, you download winscp, and putty.

for putty you type in:

192.168.8.1, port 22 and click on ok, then you get asked for a user and password these are the same as the ui, user is root.

Option 1: (use vim text editor on the router)

Then you type: cd /etc/avahi and press enter, then you use vi avah(press tab to auto complete name), great you now see the configuration of avahi in front of you, to write you press the ins/insert button on your keyboard and to stop you press esc, use : to access vim options, we want to save, that would be: :wq which means write quit, :q is quiting and :q! is quiting without saving.

Option 2 (easier):

Use winscp, connect the same as putty with protocol scp, then on the right scroll back to the root directory and navigate to /etc/avahi, edit avahi-daemon.conf.

Under [reflector] you add or change it to enable-reflector=yes, and for security under [server] you add this line deny-interfaces=pppoe-wan,wan,wgclient note that alllow-interfaces exists too but it fails on recent OpenWrts.

Then on putty type /etc/init.d/avahi-deamon stop && /etc/init.d/avahi-deamon start, then type logread to see what avahi listens to and check google Home.

It is possible you still need a firewall rule, try setting forwarding to accept on iot.

And try to add zone iot on zone lan only as destination forward.

What avahi is supposed to do is:

it listens on all subnets to the broadcast mdns traffic and mirrors it as 0.0.0.0, each subnet has a gateway, basicly the 0.0.0.0, and this way avahi broadcast the mdns to other subnets.

So I did what you suggested, the avahi stuff seemed to not cause any errors but the google home app still can't see the home mini (since it's easier as it won't stay connected if the google home app can't see it).

I can see the mini connecting to the IOT vlan:

but the google home app is just not seeing it.

I did add some forwarding rules to the fire-wall but I admit to being unsure if this is correct:

As I understand it, it means that anything in the LAN (wifi, wired, etc) can see/interact with anything in WAN/IOT and that IOT can see/interact with anything in WAN/LAN.