Part VI: IPv4 Design and Troubleshooting

Chapter 21: Subnet Design

Chapter 22: Variable-Length Subnet Masks

Chapter 23: IPv4 Troubleshooting Tools

Chapter 24: Troubleshooting IPv4 Routing

Part VI Review

Implementing IPv4 means planning for IPv4 addressing and subnetting, and then configuring the addresses and masks on hosts and routers. To help you learn to do that, Part IV introduced the basics of IPv4 addressing, and Part V then showed how to implement addressing and IPv4 routing on routers and hosts.

Part VI continues with those same topics, but with a deeper look. This part begins with two more chapters about subnetting, both of which require you to think about design. Instead of focusing on one mask, one address, or one subnet, the work looks at the entire enterprise network. What subnets could be used? Which ones are currently in use or planned for use? Which other subnets could be used? Chapter 21 looks at those questions while still using a single mask throughout the design, and Chapter 22 looks at those questions (and the common mistakes) when using different masks with different subnets.

The next two chapters continue the theme of taking a deeper look at IPv4, but instead of design, these chapters focus on troubleshooting. Chapter 23 shows how to use the most common tools to troubleshoot IPv4 routing problems, namely ping and traceroute. Chapter 24 then shows applied IPv4 troubleshooting. That final chapter in this part discusses a variety of IPv4 issues, with explanations of the symptoms as well as lists of the possible root causes.