Part V: IPv4 Routing
Parts V and VI work together to reveal the details of how to implement IPv4 routing in Cisco routers. To that end, Part V focuses on the most common features for Cisco routers, including IP address configuration, connected routes, and static routes. Part VI then goes into some detail about the one IP routing protocol discussed in this book: OSPF Version 2 (OSPFv2).
Part V follows a progression of topics. First, Chapter 15 examines the fundamentals of routers—the physical components, how to access the router command-line interface (CLI), and the configuration process. Chapter 15 makes a close comparison of the switch CLI and its basic administrative commands so that you have to learn only new commands that apply to routers but not to switches.
Chapter 16 then moves on to discuss how to configure routers to route IPv4 packets in the most basic designs. Those designs require a simple IP address/mask configuration on each interface, with the addition of a static route command—a command that directly configures a route into the IP routing table—for each destination subnet.
By the end of Chapter 16, you should have a solid understanding of how to enable IP addressing and routing in a Cisco router, so Chapter 17 continues the progression into more challenging but more realistic configurations related to routing between subnets in a LAN environment. Most LANs use many VLANs, with one subnet per VLAN. Cisco routers and switches can be configured to route packets between those subnets, with more than a few twists in the configuration.
Finally, Part V closes with a chapter about troubleshooting IPv4 routing. The chapter features the ping and traceroute commands, two commands that can help you discover not only whether a routing problem exists but also where the problem exists. Chapters 15, 16, and 17 show how to confirm whether a route has been added to one router’s routing table, while the commands discussed in Chapter 18 teach you how to test the end-to-end routes from sending host to receiving host.
Chapter 15: Operating Cisco Routers
Chapter 16: Configuring IPv4 Addressing and Static Routes
Chapter 17: IP Routing in the LAN