Why?

I had set an Omada ER605 so I could put IoT devices on another network, without it talking to my main network, but casting to my Chromecasts and using the LG Sounbar app didn't work, I needed to be on the same VLAN.

I solved this with a little bit of googling, so, here it is:

Solution

Log into Omada

Open your Omada panel by going to omada.tplinkcloud.com.
Now, choose your controller and site.

Adding Bonjour services

Open settings, and in the tab Profiles, choose Bonjour Service.
Here, add a new service by pressing Create New Bonjour Service.
You can use the following casting services:

_airplay._tcp.local
_raop._tcp.local
_appletv-v2._tcp.local

AirPlay (available by default)¹

_display._tcp.local

Miracast²

_googlecast._tcp.local
_googlezone._tcp.local

Google Chromecast³

_lg-smart-device._tcp.local

LG Soundbar⁴

_spotify-connect._tcp.local

Spotify Connect⁵

_sonos._tcp.local

SONOS⁵

_androidtvremote._tcp.local

Android TV⁶

_amazonecho-remote._tcp
_homekit._tcp.local
_workstation._tcp.local

Amazon Echo⁶

_amzn-wplay._tcp.local

Amazon TV⁶

_aqara-setup._tcp.local
_aqara._tcp.local

Aqara⁶

_hap._tcp.local

Apple HomeKit⁶

_companion-link._tcp.local

Apple TV iPhone Remote⁶

_bose._tcp.local

Bose⁶

_philipshue._tcp.local

Philips Hue⁶

_roku._tcp.local
_rsp._tcp.local

Roku Media Player⁶

_tplink._tcp.local`

TP-Link⁶

_udisks-ssh._tcp.local

Ubuntu and Raspberry Pi advertisement⁶

_nanoleafapi._tcp.local

Nanoleaf API

_home-assistant._tcp.local

Home Assistant

_fbox._tcp.local

FRITZ!Box

_tr064._tcp.local

TR064

Allowing mDNS through VLANs

Now, open the Services page, and choose the mDNS tab.
Create a new rule by pressing Create New Rule.

Here, give it a name, like "Allow Casting through VLANs"
Tick the Enable box
Device type should be Gateway
Choose the services we just configured

❕

Choose all VLANs at the Services Network and Client Network, as it will not work if you don't, even when a VLAN isn't chosen that doesn't have anything to do with it. (This is a bug)

Now press Apply, and you're done!

Sources

1: Omada itself

2: reddit.com/r/sysadmin/comments/x1fqh9/comment/imdxxzq

3: reddit.com/r/TPLink_Omada/comments/10du4a5 and community.tp-link.com/en/business/forum/topic/632058

4: reddit.com/r/Cisco/comments/av1fdd

5: community.tp-link.com/en/business/forum/topic/632058

6: community.tp-link.com/en/business/forum/topic/632856

mDNS discovery through VLANs in TP-Link Omada