Are we running out of IP addresses? 5 facts to know

IP addresses in an hourglass.

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