VLSM Example

You follow the same steps in performing VLSM as you did when performing classical subnetting.

Consider Figure 2-1 as you work through an example. Figure 2-1 Sample Network Needing a VLSM Address Plan

50 Hosts

50 Hosts

27 Hosts B

12 Hosts C

12 Hosts D

A Class C network—192.168.100.0/24—is assigned. You need to create an IP plan for this network using VLSM.

Once again, you cannot use the N bits—192.168.100. You can use only the H bits. Therefore, ignore the N bits, because they cannot change!

The steps to create an IP plan using VLSM for the network illustrated in Figure 2-1 are as follows:

Step 1 Determine how many H bits will be needed to satisfy the largest network.

Step 2 Pick a subnet for the largest network to use.

Step 3 Pick the next largest network to work with.

Step 4 Pick the third largest network to work with.

Step 5 Determine network numbers for serial links.

The remainder of the chapter details what is involved with each step of the process.

Was this article helpful?

0 0

Post a comment