The Inefficiencies of FLSM

Chapter 3, “Fixed-Length Subnet Masks,” showed you how FLSM lets you conserve the IP address space by creating locally significant subnetwork addresses. The benefit of this is that you can use a single network address to service multiple local networks. But in the real world, those local networks are seldom the same size. Thus, implementing FLSM actually wastes IP addresses. To better illustrate this point, consider the network shown in Figure 4-1. We will use this basic network diagram as the basis for exploring VLSM throughout this chapter.

Figure 4-1. Sample Network

This example is simplified throughout this chapter ...

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