The Purpose of Subnetting

What is the point to subnet your network? Methods like VLAN’s and segregating your broadcast domains might be sufficient for security, so where does that leave Subnetting at? The answer might surprise you.

Subnetting’s historic reasoning comes from the lack of IP address space in Version 4. Considering that IPv4 as it is also know is running out addresses, Subnetting came along as the great answer to maximize the wasted resources.

IPv6 and the “endless” supply of IP’s that it promises are offered up in lieu, but with more abundance comes more devices that will surely be made to use an IP address for communication online.

While VLAN’s are great, they don’t enable other networks to understand where to send outside packets to. Outside IP addresses are required for communication between ISPs, not internet. VLAN’s are for internal use while subnetting through IPv6 gives the outside world more IP addresses to choose from.

We subnet because we have too! That is the purpose of it. We are running out of IP addresses to use and this means a creative way to get additional IPs. One major reason for this boom in need is the wide adoption of Internet connected smartphones in addition to the growing list of new users on the Internet from places they have not typically been like developing countries. As those developing countries actually develop, the demand and availability for Internet access grows. Internet access requires an IP address.

The purpose of subnetting is using deep calculations through the subnet mask to maximize the IP range available. With Internet growth comes IP address growth. With IP address growth comes subnetting.