[HellishOlolo]

Hello! I have a TRENDnet TEW-811DRU with a DD-WRT v3.0-r31825 mini (04/06/17) in it. I need to set an IPTV STB in one port and use others for internet. My provider uses vlan mux ids in setting their routers, and I can't quite use it right, i guess. VID for internet is 3004 and for IPTV is 1506. So, on their firmware setting things up is pretty easy - they just create two different WAN services, one for pppoe through eth0 and the other is bridged through eth0 for IPTV with different Vlan Mux IDs and create two interface groups with two different WAN services for different eth ports. Easy-peasy.

And I don't understand at all how to do it right on dd-wrt. I love my gigabit router, so I don't want to give it up.
I already tried moving needed port to WAN's vlan2 and it seems that STB gets an IP from provider, but router itself doesn't.
So, basically, what I need is this

[Per Yngve Berg]

You are out of luck with a Beoadcom unit that supports VID 0-16 only.