Creating a network for three separate businesses in one building What would be best practice in terms of creating a network to satisfy three separate businesses located in one building? The building in question has three floors, each floor has 25 workstations and 2 printers. The building itself has only one external IP address. My current plan is a backbone from router which has 4 interfaces going to a switch on each floor located in the server room on each floor, a firewall would separate the router and switch ensuring that each business cant access another businesses devices. Could I assign each interface on the router as follows: 1. Ground floor: 192.168.0.1 2. First floor: 192.168.1.1 3. Second floor: 192.168.2.1 Range for devices on ground floor: 192.168.0.10-35 Range for devices on first floor: 192.168.1.10-35 Range for devices on first floor: 192.168.2.10-35 Is this the correct way of going about this?

Your plan seems sound (from a high level view). You can use almost any addressing scheme that makes sense to you, as long as you can summarize each business' block of IPs. If a business spans more than one floor, your scheme will not work.

Instead of assigning ranges by floor, assign a unique block for each business. That will make firewalling much easier.