Since 1998 the Internet Engineering Task Force (IETF) has developed a method for us to overcome some of the limitations of our current IP infrastructure. Known as Internet Protocol version 6 (IPv6), it corrected some of the issues that were plaguing IPv4 (the predecessor) and extended the addressing space to accommodate the myriad of new devices that now connect to the Internet. Still, there are many ISPs that have either failed to implement IPv6 entirely or have only done a partial job. What’s the holdup? Should you be worried?
Why IPv6 Is Important
IPv4 allows just over 4 billion addresses to be allocated worldwide. Each address has four numbers, each ranging from 0 to 255. This constitutes a 4-byte grouping with each byte’s value separated by a dot in standard notation (e.g., 116.184.122.205).
There are over 8 billion people on the planet and many of them own more than one device that occupies a public IP address. That’s not even mentioning how many companies own large swathes of IPv4 addresses known as IP ranges. At some point, we start to run out of IP addresses.
These addresses are controlled by regional internet registries (RIRs), each responsible for a region of the world. Reports have already been trickling in about a few RIRs running completely out of IP addresses and allocating the very last one that they’re allowed to.
In 2011, the Asia Pacific Network Information Center (NIC) was the first one to announce that it had allocated its last possible address from its pool. This was followed by an announcement on November 2019 by the Réseaux IP Européens (RIPE) that all European IPv4 addresses have been completely exhausted.
To combat this, RIRs have been campaigning for the expedited adoption of IPv6, which increases the addressing space significantly. Although they look a lot more complicated (something like fe80::f24e:bb6e:2876:c2dc), IPv6 addresses are just typically presented as eight groupings of 16-bit hexadecimal values.
They are often shortened by eliminating the full-zero (0000) groupings, but they always form a full 128-bit number, which allows for so many addresses that it’s silly to even repeat the exact number. It’s 340,282,366,920,938,463,463,374,607,431,768,211,456, by the way.
Slow Adoption Boils Down to Economy
If you have strong powers of deduction, you may have guessed that the reason why ISPs aren’t so quick to adopt IPv6 has a lot to do with balance sheets. If you run a company that provides Internet to millions of people, you’re going to have to replace a lot of equipment along your pipeline.
It’s not as if though you can just push out a simple firmware update. You need to replace all of your older equipment which cannot route IPv6 connections with something that can do both v6 and v4. Likewise, if you distribute your end customers’ own routers, you’ll also need to replace all of those, too. You also have to rely on your customers having the network interfaces necessary to authenticate with IPv6 addresses.
Once you get to over a million customers in different geographical regions of a country, the economic factor scales up significantly. You’re paying a lot of people a lot of money to replace expensive equipment all so you can use a new set of numerical addresses. If you still have lots of free IPv4 addresses in your network’s range, you might just hold off on this decision.
Let’s also not forget to mention that all IPv6 routing equipment still has to be designed with backward protocol compatibility in mind. IPv4 continues to be widely used by server endpoints, meaning that ISPs offering IPv6 addresses to end customers must have a way to bridge them over when connecting to these servers. This bridging issue also led to a lot of headaches, especially since ISPs that adopted IPv6 often had to give their clients an IPv4 endpoint to connect with anyway.
On the other hand, servers using IPv6 addresses will not be able to communicate with clients that only have IPv4 addresses.
The Shortcomings of NATs
For a long time, ISPs that held off on adopting IPv6 relied on several layers of network address translation (NAT) devices, including the tendency of their own customers to use routers with the technology. A NAT translates one network IP to the requests and signals of another IP, allowing multiple devices to share one address while each possessing a different internal one.
Since the late 90s, this has become a staple of home and office networking, stemming the tide of IPv4 address exhaustion and presenting a possible solution. The problem here is that besides the fact that the technology had many flaws when applied to larger scales, it also didn’t account for a lot of mobile traffic that would come in the following decades.
The proliferation of LTE and 5G mobile connectivity and its pervasiveness in emerging economies has made NAT less relevant. When you go outside of your home’s Wi-Fi network, your phone will connect to the mobile network and pick up its own IP address. If your router back home is authenticated to your ISP and you live alone, you are now occupying two IP addresses. Each member of your household with a phone will occupy an additional one as soon as they leave the range of the home Wi-Fi network.
Slowly, but surely, this led to IP address exhaustion on a local countrywide level in a great number of nations. For example, Romania, Argentina, Turkey, Poland, Mexico, Russia, and Brazil, experienced rapid IP address exhaustion due to having an address space that accounts for half or less of their populations. With the boom of connectivity that they’ve all experienced coupled with the increased amount of mobile traffic, they were forced to quickly upgrade their infrastructures to ensure connectivity through IPv6 when other addresses are unavailable.
With all of this in mind, it’s no surprise that IPv6 adoption has been creeping up steadily over the years, albeit with some recent difficulties due to all the context provided previously.
Should You Be Worried About Slow Adoption?
Just because your ISP is slow to adopt doesn’t mean that they’re not monitoring the situation closely. It’s in their interest that they ensure the best possible connectivity for you, especially if they’re competing with several other providers. Don’t forget that a lot of the more recent adoption numbers come from competitive pressure to maintain connectivity as a result of local IPv4 exhaustion.
As I’ve mentioned before, despite the slow progress, the worldwide situation is still pretty great. Whereas Google assessed in 2015 that only a little bit above 5% of internet traffic originated from IPv6 clients, in 2024, it’s at closer to half of all traffic!
Image credit: PickPik; screenshots by author.
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