The author is proposing a solution that is a naive implementation of an existing technology: VLANs. This is what you want to do: * Isolate each group of devic

The author is proposing a solution that is a naive implementation of an existing technology: VLANs. This is what you want to do: * Isolate each group of devices with different VLANs * Use firewall rules on your layer 3 device (router, firewall, frankenmodem, etc.) to prevent communication between the subnets tied to those VLANs. This is an example of what this looks like at layer 3: https://documentation.meraki.com/MR/Firewall_and_Traffic_Shaping/Using_Layer_3_Firewall_Rules https://documentation.meraki.com/MR/Firewall_and_Traffic_Sha...