For example, Example 22-2 lists the routing table on Albuquerque from Figure 22-1 Albuquerque uses masks /24 and /30 inside network 10.0.0.0, as noted in the highlighted line in the example. This chapter removes that restriction by introducing variable-length subnet masks ( VLSM). If you used a network address such as 172.16.2.0 with an 8-bit subnetting mask (the entire third octet), you would be wasting 252 addresses for a WAN point-to-point link that needs only two addresses.
A simple example of VLSM can be demonstrated through a connection between two Cisco routers over a wide area network (WAN) serial link. Variable-Length Subnet Masking ( VLSM) See See Variable Length Subnet Masking ( VLSM) is a more efficient way of subnetting because it allows you. Example subnets with host address ranges. Using the BlockSize that you have calculated in Step 1, you can find the number of bits required for host address after subnetting (Lets call it HBits) by the following calculation: BlockSize =2 HBits. Or you can choose the number of subnets you want. You can choose the number of hosts that can connect to each subnet.
You can select the subnet mask that will always be equal or superior to the original network mask. Here you can configure the parameters for subnetting calculation. Example 22-2 Albuquerque Routing Table with VLSM.