You have just been hired by a new company and need to add on to their existing network.
There are no restrictions to prevent you from starting over with a completely new IP address
scheme. Should you use a VLSM classless network or opt for a classful network?
Let’s say you happen to have plenty of address space because you’re using the Class A
10.0.0.0 private network address, so you really can’t imagine that you’d ever run out of
IP addresses. So why would you want to bother with the VLSM design process in this
environment?
Good question! Here’s your answer…
By creating contiguous blocks of addresses to specific areas of your network, you can
then easily summarize the network and keep route updates with a routing protocol to a
minimum. Why would anyone want to advertise hundreds of networks between buildings
when you can just send one summary route between buildings and achieve the same
result? This approach will optimize the network’s performance dramatically!