9.18 Revisiting a Simple Local Network

Now we’ll look at additional components of the simple network introduced in Section 9.4. This network consists of one LAN as a subnet and a router that connects the subnet to the rest of the internet. You’ll learn the following:

• How a host on the subnet automatically gets its network configuration
• How to set up routing
• What a router really is
• How to know which IP addresses to use for the subnet
• How to set up firewalls to filter out unwanted traffic from the internet

For the most part, we’ll concentrate on IPv4 (if for no other reason than that the addresses are easier to read), but when IPv6 differs, you’ll see how.

Let’s start by looking at how a host on the subnet automatically gets its network configuration.