My GL.iNet GL-AR750 has eth0 and eth1. Eth1 has a switch and eth1 is vlan capable.
Since only eth0 is POE-capable and I want to build a wlan-AP with more SSID I need vlan using eth0.
Is that possible?
I believe you want to create subinterfaces directly on eth0.
You can try it by defining eth0.10 for example as interface name.
Okay, this is only possible with uci but not with luci.
Thanks for your help!
In Luci as well.
Just add a custom interface name at the bottom of the drop down list in the Add Interface screen.
this do not work. If I write 'eth0.2', I can't select it.
Write it and press Enter.
Sorry, ENTER 
Now it works on luci too
thanks!