Running IPv6

- Iljitsch van Beijnum

After five yearly IPv4 address use reports I've now comipled the first IPv6 address use report!

I've been writing for Ars Technica lately, including some articles about IPv6:

• "Everything you need to know about IPv6"
• New Airport Extreme could expose Macs via IPv6
• IPv6 firewalling knows no middle ground
• ARIN: It's time to migrate to IPv6

The Internet Protocol Journal has published the article IPv6 Internals, adapted from the chapter with the same name in the book.

Get your own IPv6 address block. Until now, only ISPs could get their own independent IPv6 address block. But ARIN, the organization in charge of IP address distribution in North America, has changed its rules so that now it's possible for end-user organizations to get their own IPv6 address block as long as they qualify for one in IPv4 too. Having a Provider Independent address block makes it possible to move from one ISP to another without renumbering, or even to connect to more than one ISP at the same time for increased reliability (this is called "multihoming"). However, this decision also has some downsides.

IPv6 is the next generation Internet Protocol that has been developed over the past decade by the Internet Engineering Task Force (IETF) as a replacement for the current IP (IPv4 or TCP/IP) protocol. TCP/IP was never designed for a network as large as today's internet. The main problem is that the address length is only 32 bits, which allows for about 3.7 billion usable addresses. That doesn't even allow for a single address per person on the planet. In IPv6, addresses are 128 bits in size, which gives us more addresses than we can reasonably count (3.4x10^38).

Are we running out of IP addresses?
That's a long story... See my Apress blog post about this subject. The short answer: today's best guess is around 2012. See this follow-up for some thoughts about what's going to happen when there are no longer any free IPv4 addresses left.

I've compiled a 2005 IPv4 Address Use Report that details how many IPv4 addresses were used up during 2005 (some 166 million). The 2006 IPv4 Address Use Report shows a very similar number. There are also some other interesting details in there, such as a comparison with earlier years and trends in the size of address blocks, as well as a look at the distribution of IPv4 addresses around the globe. Also see Peter van Eijk's weblog (as well as mine) for some more thoughts and numbers in this area.

My book "Running IPv6":

Some reviews:

• Unix Review
• The Internet Protocol Journal

More information about the book is available at:

• The book at Apress
• The sample chapter about the DNS at Apress
• The book at Amazon
• The book at Amazon UK
• The book at Bookpool

The book was published in the second half of November 2005 by Apress. As you can guess from the title, it's about running IPv6. Most of the prior books about IPv6 focus on how the different parts of the protocol fit together, so they end up describing the theory of IPv6. In my book, I wanted to show what you can do with IPv6 today, on common operating systems such as Windows XP, MacOS X, Linux and FreeBSD, as well as discuss the Cisco or Juniper router configurations necessary to move IPv6 packets around the network.

An ebook version is available directly from the Apress website. Apress ebooks are in DRM-free PDF format for easy reading and searching. The ebook version costs $34.99.

I've also written a book about the Border Gateway Protocol and I have a website about BGP (also some IPv6 information) and a website about me.

Last update: January 2, 2010.