IPv4 is here to stay with us for a good few years yet, reckons the the Réseaux IP Européens Network Coordination Centre's (RIPE NCC) public policy manager, eight years after IPv6 was supposed to replace it.
Marco Hogewoning, public policy for the Amsterdam, Netherlands-based European regional internet registry, told The Register that despite the best efforts of IPv6 proponents over the last eight years, it might take "five to 10 years" before the world starts to truly abandon the IPv4 address space.
IPv6 was first defined in 1996, but with today marking the 8th anniversary of (the second) IPv6 "Launch" Day, RIPE NCC was keen to talk up the tech, whose chief benefit is that it provides a much greater pile of internet addresses for all the stuff humanity has dumped online in the last few decades.
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As techies know, everything on the internet has an address so your granny's fondleslab knows where to fetch her cat videos from. When what we currently know as the internet came into widespread use, the system for allocating those addresses was called IPv4. That had capacity for about 2 billion IP addresses.
After the last decade of dolts connecting fridges, lightbulbs and other junk to the internet, each one of those devices needing access to an IP address, humanity ran out of unallocated IPv4 addresses in November 2019.
Smart people had foreseen the problem of IoT vendors' natural growth over time. About a decade ago, IPv6 came into being. It allows for 2^128 possible addresses, compared to IPv4’s 2^32.
Musing that "little pockets of IPv4" and some government services hosted on IPv4 are two of the things holding the world back, Hogewoning told The Register:
"It's impossible for me to file my taxes over IPv6. As much as I want, I can't get rid of IPv4 in the end because I need to file my taxes. That's a dialogue we try to have with the governments … It's an important step to go to, enabling IPv6 [instead of] IPv4 to make sure we don't force people to have that backwards compatibility."
He continued, gently extolling the virtues of IPv6: "There's a lot of techies who say, 'In terms of standardisation it's really mature, it's an internet standard.' We know it's proven technology; we still have discussions with people who say 'Are you sure it's going to work?' It's tech. It's over 25 years old at heart!"
The Internet Society's Mat Ford agreed, telling The Register: "We now have a situation where about a third of the traffic that reaches google is over IPv6, some of the major mobile networks in the US for example; almost all of their traffic is carried over IPv6. It is a mature protocol and it works for very large network operators to deliver content."
It's not as simple as a mere technical challenge, however. As we reported in 2018, there is a complex and arcane set of arrangements underpinning the global internet traffic peering system. Not all players in that system are equal; by virtue of whatever contracts and agreements are in force at a given time, some peers hold far more clout in certain regions than others.
In turn, that means if a certain network at a bottleneck switches to IPv6 – or sticks with IPv4, or continues with network address translation provision so non-IPv6 traffic can continue to flow – that is a powerful incentive for its peering neighbours to do the same. The entire world is only going to switch to IPv6 when there's enough of an economic incentive to do so. At the moment large parts of the internet work well enough and don't appear, as far as some are concerned, to need fixing just yet.
Making the case for a move...
Hogewoning told El Reg that moves to withdraw IPv4 have been discussed plenty of times, but cautioned: "This is all looking into the future and I'm not expecting any massive drastic steps in the next decade. But you expect people in industry [to ask]: Will there be a threshold? Will it be worth having that IPv4 – what I refer to as legacy interfaces – available compared to all my users already coming into IPv6? That's kind of the opposite of the dialogue we've been in over the last five years."
The Internet Society's Ford added: "IPv4 still works. For many small operators and enterprise networks, the incentives are to start there, to invest the money to migrate to ipv6. In many cases those aren’t particularly great but until there's a real cost associated with maintaining the status quo with IPv4, there isn't a strong business incentive to move to IPv6 for some networks."
In fairness to IoT suppliers, they're not the only culprits for the rapid explosion in required IP addresses; Ford pointed out that many smart TVs and set-top boxes, for example, are still IPv4-only even in this day and age: "Provided the network these devices are deployed in supports it, there's no strong business incentive for them to support IPv6 either."
Until the economics shift decisively in favour of dumping IPv4 support, it looks like the venerable old technology will be with us for a long time to come. ®