Purpose and Command Syntax OF IP Route

Purpose and Command Syntax of ip route

As we have discussed previously, a router can learn about remote networks in one of two ways:
Manually, from configured static routes
Automatically, from a dynamic routing protocol

The rest of this chapter focuses on configuring static routes. Dynamic routing protocols are introduced in the next chapter.

Static routes



Static routes are commonly used when routing from a network to a stub network. A stub network is a network accessed by a single route. For an example, see the figure. Here we see that any network attached to R1 would only have one way to reach other destinations, whether to networks attached to R2 or to destinations beyond R2. Therefore, network 172.16.3.0 is a stub network and R1 is a stub router.

Running a routing protocol between R1 and R2 is a waste of resources because R1 has only one way out for sending non-local traffic. Therefore, static routes are configured for connectivity to remote networks that are not directly connected to a router. Again, referring to the figure, we would configure a static route on R1 to the LAN attached to R2. We will also see how to configure a default static route from R1 to R2 later in the chapter so that R1 can send traffic to any destination beyond R2.