What Is IPv4? IPv6? Why Is This Important?

IPv4 Address

Indeterminate [Public domain]/Wikimedia Commons

Perhaps you've read that IPv4 is "running out of addresses" and that the new "IPv6" is going to solve the problem. Here's why.

Until 2010, the world was at risk of running out of available computer addresses. You see, every device that connects to the Internet needs a serial number, much like every legal car on the road requires a license plate. But just like the six or eight characters of a license plate are limited, there is a mathematical limit to how many different addresses are possible for internet devices.
The original internet addressing system is called 'Internet Protocol, Version 4' (IPv4), and it has numbered the computers of the Internet successfully for years. By employing 32-bits of recombined digits, IPv4 has a maximum of 4.3 billion possible addresses.

  • Example IPf4 address:
  • Example IPf4 address:

Now, while 4.3 billion addresses might seem plentiful, the Internet was going to exceed this number of devices by the end of 2012. Every computer, every cell phone, every iPad, every printer, every PlayStation, and even soda machines require an IP address. There are not enough IPv4 addresses for all these devices!

Good news: a new internet addressing system is here, and it will fill our need for more computer addresses. Internet Protocol version 6 (IPv6) is currently being rolled out across the globe, and its enlarged addressing system will fix the limitation of IPv4. You see, IPv6 uses 128 bits instead of 32 bits for its addresses, creating 3.4 x 10^38 possible addresses (that is a 'trillion-trillion-trillion'; undecillion' is an obscure term that describes this impossibly large number). These trillions of new IPv6 addresses will meet the internet demand for the foreseeable future.

  • Example IPv6 address: 3ffe:1900:4545:3:200:f8ff:fe21:67cf
  • Example IPv6 address: 21DA:D3:0:2F3B:2AA:FF:FE28:9C5A

When Is the World Switching Fully Over to IPv6?

The world has already started embracing IPv6, with the big web properties of Google and Facebook officially doing so as of June 2012. Other organizations are slower than others to make the switch. Because lengthening each possible device address requires so much administration, this massive switch won't be complete overnight. But the urgency is there, and private and government bodies are indeed transitioning now. Expect IPv6 to be a universal standard by the end of 2012.

Will the IPv4-To-IPv6 Change Affect Me?

The change will be largely invisible to most computer users. Because IPv6 will largely happen behind the scenes, you will not have to learn anything new to be a computer user, nor will you have to likely do anything special to own a computer device. In 2012, if you insist on owning an older device with older software, you might need to download special software patches to be compatible with IPv6. More likely: you will be buying a new computer or new smartphone in 2012, and the IPv6 standard will already be embedded for you.
In short, the switch from IPv4 to IPv6 is much less dramatic or frightening than the Y2K transition was. It is a good techno-trivia issue to be aware of, but there is no risk of you losing access to the Internet because of the IP addressing issue. Your computer life should be largely uninterrupted because of the IPv4-to-IPv6 transition. Just get used to saying 'IPv6' out loud as matter of regular computer life.+