It’s been over ten years since the launch of IPv6, the Internet address system that was supposed to give us nearly infinite number of IP addresses. But after a decade of implementation, just over 21% of all websites worldwide will support IPv6 addresses.

On the surface, this makes no sense. The original IPv4 standard only supports about 4.3 billion IP addresses. We clearly have far more people and devices connected to the Internet than that number. By contrast, IPv6 provides 340 trillion trillion trillion IP addresses, a number that, for all practical purposes, is unlimited.

Even though we exhausted the supply of IPv4 addresses years ago, it doesn’t look like there is any rush for most of the world to move to the new IP addresses. There are obvious barriers to making the conversion that most ISPs and businesses are not ready to tackle. Most of the barriers to making the conversion can be categorized as hardware limitations, lack of training, and the overall cost of the conversion.

It’s a little hard to believe after a decade, but many older computers, servers, and routers will still not recognize IPv6 addresses. One would have to think that we’ll eventually ditch the older devices, but there are apparently still a huge number of devices that can’t process IPv6 addresses. The good news is that newer operating systems and devices will handle the new addresses. But the world still has plenty of folks using older versions of Windows, Linux, Android, and iOS. Big corporations are reluctant to make the switch to IPv6 out of fear of older technology around the company that would stop working. Smaller companies are not willing to make the change until they have no choice.

This issue is compounded by the fact that direct communication between IPv4 and IPv6 devices is impossible, and all exchange of data must pass through an IPv4/IPv6 dual-stack conversion to enable communications. This was originally envisioned as a temporary fix, but as IPv4 continues to be used, this is looking to be permanent.

Companies are also loath to tackle the cost and effort of the upgrade without some compelling reason to do so. Companies that have made the change report a number of unexpected problems with a conversion that can be disruptive, and companies are not willing to tackle something this complicated unless they have to.

It’s interesting to see how various countries have decided to make the switch to IPv6. Google has been collecting statistics on IPv6 conversions that are summarized on this map. At the time I wrote this blog, the world leaders in conversion to IPv6 are France (75%), India (68%), Germany (67%), Malaysia (62%), and Saudi Arabia (61%). Much of the rest of the world is far behind with the upgrade, including Russia (7%), China (3%), and much of Africa below 1%.

The US is just above 50% utilization of IPv6. Interestingly, the US backslid and was at a 56% IPv6 conversion rate in 2019. The resurgence of IPv4 is being credited to the huge flood of folks working at home during the pandemic – since residential ISPs have mostly not made the conversion.

Internet experts believe we’ll still be running dual IPv4 and IPv6 networks for at least a few more decades. We’ve found ways to work around the lack of IPv4 addresses, and very few companies or ISPs are seeing any urgency to rush toward a conversion. But as the worldwide penetration of broadband continues to grow and as we add more connected devices, the pressure will increase to eventually make the conversion. But don’t expect to see any headlines because it’s not happening any time soon.