Skip to content

What is IPv4 Exhaustion?

IPv4 exhaustion is the point at which the internet runs out of new, unused, IPv4 addresses to assign new devices. IPv4 (Internet Protocol version 4) uses a 32-bit address system, which means it can create about 4.3 billion unique IP addresses.

4.3 billion sounds like a lot, but when you consider the billions of people, smartphones, laptops, servers, IoT devices, and always-on connections, you can see how quickly all these IP addresses get used up.

IPv4 was created in the early days of the internet, when no one expected such global scale or explosion of internet-connected devices. In addition, large blocks of IPs were given out before anyone realized there would be a scarcity of IPv4 addresses.

When did IPv4 run out? The global pool effectively ended in 2011, and regional registries ran out in the several years after that: North America’s IPs ran out in 2015 and Europe’s in 2019. 

So how is the internet still working? The internet didn’t break when we ran out of IPv4 addresses because we came up with workarounds:

  • NAT (Network Address Translation) allows many devices to share one public IP (for example, your whole home network)
  • IP leasing and transfers let companies buy or sell unused IP addresses
  • IPv6 is the new protocol to ultimately replace IPv4 addresses, with virtually unlimited IPs.