It looks like the internet forecasters were optimistic when they designed the current IP address architecture known as IPv4. They figured 4 billion addresses would be enough. But this was back in the eighties, when practically no one was on the World Wide Web, commercial WiFi applications were practically nonexistent, and smart phones that could surf the internet didn’t exist. Thirty years later, we are scraping the bottom of the IPv4 address barrel. Luckily, the smart guys have been working on this for awhile, with the result that we will soon be connecting to the web via IPv6.

One of my college buddies was a math major. His first job out of college was with Bellsouth, where he worked in the forecasting department. If I can remember how he described it correctly, their job was to try to predict from current usage patterns where phone service was likely to grow the fastest, so the company could plan the expansion of their infrastructure more efficiently.

It’s the kind of thing you don’t even think about if you are a layman.

My buddy moved on from this job years ago, before cell phones became ubiquitous, but I wondered when I first saw the IPv6 stories starting to circulate what kind of challenge their growth would have posed to him and his colleagues. We all know what eventually happened to the phone companies—they had to alter the age-old geographic area oriented system in favor of a more fluid solution that meant you could no longer pinpoint where a person lived by their phone number prefix.  

IPv4 relied on 32 bit addresses. IPv6 uses 128 bit addresses.

The IPv4 addressing capability is approximately 4 billion IP addresses. The very large IPv6 address space supports a total of 2128 (about 3.4×1038) addresses—or approximately 5×1028 (roughly 295) addresses for each of the roughly 6.8 billion (6.8×109) people alive in 2010. In another perspective, this is the same number of IP addresses per person as the number of atoms in a metric ton of carbon.


If you are so technically inclined, you can click here and here to get a detailed rundown of IP address exhaustion. Or check here to read more about the July 1, 2010 deadline requiring evidence of IPv6 compliance by government suppliers in order to obtain new government contracts. But if you are like me, what you really want to know is how this affects the computer equipment and internet connectivity in which you’ve already invested.

Most cable modems and DSL modems we currently use at home are not IPv6 compliant. Some of this equipment can be upgraded by downloading new software, so you may be able to continue using what you already have. There are a few new models on the market that are IPv6 ready now—expect an avalanche of new products to hit the market soon. If you get your internet connection through one of the dominant ISP’s in the marketplace, though, you will probably have very little to worry about.

The end result of the protocol switch, which is expected to take as long as several years, will nevertheless change once again how the internet interacts in our daily lives by multiplying the number of electronic appliances and gadgets that could potentially have their own IP addresses.