What is IPv6 and Where Did it Come From?

There are lots of articles and resources around the internet on IPv6 — especially since World IPv6 Day is today.

Rather than recap them here, I thought I’d share a few of the less frequently asked questions about IPv6.

What happened to IPv5?

According to ISOC, “Version 5 of the IP family was an experimental protocol developed in the 1980s. IPv5 (also called the Internet Stream Protocol) was never widely deployed. Since the number 5 was already allocated, this number was not considered for the successor to IPv4. Several proposals were suggested as the IPv4 successor, and each was assigned a number. In the end, it happened that the one with version number 6 was selected.”

Who got the last IPv4 address?

It’s hard to say, but what we do know is that according to the Number Resource Organization (NRO) press release, “On Monday, January 31, 2011, the Internet Assigned Numbers Authority (IANA) allocated two blocks of IPv4 address space to APNIC, the Regional Internet Registry (RIR) for the Asia Pacific region, which triggered a global policy to allocate the remaining IANA pool equally between the five RIRs. Today IANA allocated those blocks.” This means that the only IPv4 addresses left to assign are now held by regional registries (example: ARIN).

How many IPv6 addresses are there?

IPv6 holds 340,282,366,920,938,463,463,374,607,431,768,211,456 IP addresses, which is pronounced “340 undecillion, 282 decillion, 366 nonillion, 920 octillion, 938 septillion, 463 sextillion, 463 quintillion, 374 quadrillion, 607 trillion, 431 billion, 768 million, 211 thousand, 456”.

Or another way to look at it, that’s 4.9156704 × 1028 IP addresses for every person on the planet. Or, one IP address for every atom in the human body.

How can I easily check my IPv6 connectivity?

Check out the free Google gadget. It checks and reports your IPv6 connectivity. It works on all Operating Systems (Windows, Linux, Mac OS X, Android, iOS/iPhone/iPad) and Browsers. It also works on Windows Vista and Windows 7 with their ‘under-the-hood’ (read: non-name-resolving) IPv6

IPv6 Resources

The Internet Society — www.isoc.org

ARIN — www.arin.net

Free Recorded Web Seminars

Migrating to IPv6

How to Successfully Migrate from IPv4 to IPv6

Related Courses

IP6FD – IPv6 Fundamentals, Design, and Deployment v3.0

Guest Blogger: Jill Liles

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