ccna security 640-553 pdf

ccna security 640-553 pdf.10.0.4.0, 10.0.8.0, 10.0.12.0, etc. B is true for 10.0.3.255, 10.0.7.255, 10.0.11.255, 10.0.15.255, etc.; C is true for 10.0.8.1.10.0.11.255 and for host addresses in other subnets.Chapter 7 VLSMCertification Objectives7.01 VLSM Two-Minute Sprints 7.02 Routing Summary Self-Test QuestionsChapter 6 provided a brief introduction to IP addressing and subnetting, including topics such as address classes, address types (network addresses, host addresses *, and directed broadcast addresses), and IP address planning. This chapter provides a more in-depth introduction to IP addressing, exploring two new topics: variable-length subnet masks (VLSM) and route summarization. Because these two topics build on the knowledge presented in Chapter 6, if you are not familiar with IP addressing mechanisms, revisit Chapter 6 and do the exercises before reading this chapter. To perform VLSM and route summarization tasks, you must have an in-depth knowledge of subnetting.Certification Objectives 7.017.1 VLSMVLSM was originally defined in RFC 1812 to allow you to use different subnet masks in the same classified address space. For example, for a point-to-point link, 255.255.255.252 is the good subnet mask, which gives two host addresses per subnet. For LANs, 255.255.255.192 might be good subnet masks, which give 62 host addresses per segment. Using subnet mask 255.255.255.252 for the LAN would not provide enough host addresses, and using subnet mask 255.255.255.192 for point-to-point connections would waste addresses. One solution is to place links with different subnet masks in different networks to reduce address waste, but scalability is poor.VLSM solves this problem by allowing you to use different subnet masks in the same sorted address space. The next few subsections describe the benefits of VLSM and how to use VLSMo in your networkExam Essentials Remember that the optimal subnet mask for a point-to-point link is 255.255.255.252 (/30)7.1.1 Features of VLSM