Every device needs an IP address to communicate with others on the internet. There are 4.3 billion possible IP addresses in the IPv4 standard we use today. But with 4.66 billion active users on the internet, does that mean some of us don’t have an IP address?
Don’t worry, we all have an IP address to use. But things have certainly changed since the beginning of the IPv4 era—and we’ve rounded up five key facts to keep you informed.
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1. When talking about IP addresses, we’re referring to IPv4
IP (Internal Protocol) is a set of rules used by computers to communicate. When talking about IP addresses, we are mostly referring to those using the IPv4 standard. IPv4 was created in the 1980s when the internet started booming. It uses 32-bit numbers, usually written in dot-decimal notation (e.g., 172.16.254.1), which means there are 2^32, or about 4.3 billion addresses, available for worldwide use.
IPv4 has been in use for decades, so most of our IP addresses are IPv4, not IPv6, the newer IP standard. If you check your IP address—you’re most likely using an IPv4 address.
Read more: What can someone do with my IP address?
2. We’ve run out of IPv4 addresses, not IPv6
On November 25, 2019, RIPE NCC, the institution overseeing global internet resources, released their last remaining IPv4 addresses. Thankfully, the internet continues to function.
This is largely because of technologies like network address translation (NAT), which maps many private IP addresses onto one public IP. There are also markets that sell and reallocate old IPv4 addresses for reuse. But most importantly, the internet will never truly run out of IP addresses thanks to a newer standard: IPv6.
3. IPv6 allows 340 trillion, trillion, trillion IP addresses
IPv6 was first developed in the mid-1990s and launched in 2012. As the latest internet protocol version, IPv6 uses addresses that are 128 bits long, theoretically allowing a whopping 340 undecillion IP addresses for future use.
That’s enough for many times more devices than there are atoms in all of our current devices combined. Long live the internet!
4. Most of us still haven’t switched to IPv6
Don’t worry if you haven’t made the jump to IPv6. In fact, you don’t really have control over which version of IP address you use since it’s assigned by your internet service provider.
Full IPv6 adoption will require all devices, websites, and networks to be IPv6-compatible. For most businesses, upgrading to IPv6 is high effort but low return. As for many internet service providers—they’re able to grow their networks by circulating unused IPv4 addresses among their customers without changing to IPv6. To many, IPv4 is still the path of least resistance, although that may change as the price of recycled IPv4 addresses goes up.
5. IPv4 and IPv6 will coexist for some time
IPv4 and IPv6 will coexist for at least some years—or even another decade—as it’s hard to know when we will all completely move on to the latter. IPv4 and IPv6 aren’t designed to interoperate directly. An IPv4-only device can’t communicate with an IPv6 device without a network address translator, so there will likely be some growing pains. But that’s a problem for network operators and device manufacturers.
Read more: The difference between static and dynamic IP, and how to keep your IP private with a VPN
FAQ: About running out of IP addresses
How many public IP addresses are left?
None, if we’re talking about IPv4 public addresses. In 2019, RIPE NCC (the institution overseeing global internet resources) released their last remaining IPv4 addresses; there are no more new ones to assign. But if we are talking about IPv6 addresses—there are a total of 340 trillion trillion trillion of them. It’s not clear how many of these IPv6 addresses are used or left, but it shouldn’t matter, as it’s unlikely they will run out like IPv4 addresses did.
What happens when we run out of IP?
There’ll simply be more IP addresses created, most likely before the existing ones run out. Let’s take IPv4 addresses as an example. People had already anticipated they would run out one day—which they did in 2019—prompting the creation of more IP addresses (IPv6 addresses) to tackle this issue back in 1998.
Will IPv6 ever run out?
No, they are unlikely to run out. There are 340 trillion trillion trillion IPv6 addresses available, which is sufficient to cover more than the trillion internet devices on earth.
Why is IPv6 not popular?
There’s a lot of cost involved in switching over to IPv6, as many of the existing networking devices and equipment are designed for IPv4. But that’s a problem for network operators and device manufacturers. And since IPv4 is still working fine for now, not many of them have made the move.
