Isolate LAN port(s)

Does anyone know/post a step by step tutorial/link for noobs re: isolating LAN port using LuCI?
Router: D-Link DIR-882 rev.A1

Friend has couple smart tv and media boxes connected to OpenWrt router via network cable.
Those smart tvs and media boxes obviously need internet access for Netflix and such
Has no reason accessing the rest of the local network.


It has nothing to do with ports.

Step 1: create a subnet for such devices, and an interface on the router facing that subnet
Step 2: create firewall zone (for example: internet_only), and add that interface to that zone
Step 3: create a forward rule that allow internet_only zone to access your wan zone

And then all devices in that subnet cannot access those belong to your lan zone.

Sorry I do not use LuCI so I cannot give you tutorial via screenshots.