Setting up an internet gateway
As long as we're setting up network services, we may as well go all the way and set up a router to act as a gateway for our network. A gateway within a network is the device you go through to route from one network to another. In this context, the internet gateway will be the device that sits between your local network and the device that provides your internet connection (such as a cable modem). The gateway in a typical network is usually a commercial router or firewall, which often also provides DNS, DHCP, and routing services as well.
If you already have such a device on your network providing these services, then there's nothing for you to do. You can skip this section. But if you'd like to set up your own router, then feel free to proceed.
If you'd like to proceed and set up a router, then the first order of business is to decide which device on your network will serve that purpose. Often, administrators will build DNS...