IT Certification and Training Blog

Subnetting Demystified

Mar 7, 2013 8:37:00 AM / by Kelson Lawrence

By John Oden

It is 2013, and the last of the unallocated IPv4 address space was handed out by the Internet Assigned Numbers Authority (IANA) several years ago. The IT industry has been contemplating the looming depletion of the IPv4 address space since the early 2000s. Back in 2003, one would have thought that by 2013, we would be well on our way with the deployment of IPv6, which would once and for all eliminate the scarcity of available global IP addresses. Except that we're not. Not well on our way with the global deployment of IPv6, that is.

With the aid of technologies like Network Address Translation (NAT) and Port Address Translation (PAT), combined with the Request for Comments (RFC) 1918 private IP address space, we have extended the life of IPv4 far longer than anyone would have thought possible 10 years ago.

All this to say, IPv4 is alive and well, and we will continue to need to be fluent in the manipulation of the IPv4 address space for a long time to come. Additionally, an understanding of how to manipulate the IPv4 address space is essential to understanding IPv6. All of this, combined with the fact that success on the majority of IT certification exams depends on your ability to solve IPv4 addressing and subnetting problems, means that a thorough understanding of subnetting is essential to success in IT today.

To help you gain this understanding, we have put together a series of video presentations that we have entitled Subnetting Demystified. The purpose of this series is to help you master the techniques necessary to be efficient with IP subnetting.

This series will contain a total of eight video presentations when it is complete. Here is a list of the topics that will be covered:

  • Introduction
  • IP Addressing
  • Binary Math
  • Address Classes
  • CIDR Notation
  • Why Subnet?
  • Subnetting How To
  • Fast Subnetting
  • Supernetting

After viewing these presentations and working through the practice exercises, you’ll have the tools you need to work through any subnetting problem with only a pencil and paper. No subnetting tables or calculators required! If you have a question about subnetting, or any of the other topics covered in these presentations, please post a comment.


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Topics: Binary Math, CIDR Notation, Why Subnet?, Fast Subnetting, Subnetting Demystified, IPv4, IP Addressing, Address Classes, Subnetting How To

Kelson Lawrence

Written by Kelson Lawrence

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