I asked a similar question on this topic and some guys recommended use VLANs or guest network, so I asked to a friend and he will give to me a router with guest network function. However, there is a device (my father's computer) that I want to also isolate, but guest network will not work totally since this computer use cable directly connect to the router.
This is my intranetwork currently:
Another devices | Internet --- Router 1 | My father's devices
But I recently read that if I connect a cable from a router's LAN port to another router's WAN port, it's like isolate the devices, as devices in router 2 can connect to router 1, but not vice-versa.
This will work like this:
Another devices | Internet --- Router 1 --- Router 2 | My father's devices
My intention is, because security concern, isolate ALL the traffic between my father's devices and another devices in my home. So, my question is: Will the second intranetwork do that? I need, at least, that my father's devices can't communicate with another devices.