Is there a way to lock a device out of the LAN and still let it use WAN? For example, I have a guest in the house who wants a wireless WAN connection.
Fine, but if there's a way to keep the guest's device from seeing other LAN devices, I'd like to implement it.
It all depends on the feature set of the router. I have seen home routers that allow WiFi devices to have access to the Internet, but no access to the wired LAN. I think that's what you're looking for.
I'm not sure as I've seen one that can set that at the device level.