IPv4 Exhaustion FAQs

1. What is IPv4?

Internet Protocol version 4 (IPv4) is a system of addresses used to identify devices on a network. IPv4 addresses are 32-bit numbers. This means that there are 232, or just over four billion, possible addresses. When the commercial Internet was in its infancy, the pool of around four billion IPv4 addresses seemed huge and no one predicted its rapid growth. As each device connected to the Internet needs a unique IP address, over time, it became clear that more addresses would be required to ensure the continued expansion of the Internet.

2. What does “IPv4 exhaustion” mean?

It means that the central pool of available IPv4 addresses managed by the IANA (www.iana.org/numbers) is empty.

The central pool of available IPv4 addresses managed by the Internet Assigned Numbers Authority (IANA) was depleted on 3 February 2011, when each Regional Internet Registry (RIR) received one final /8 allocation of IPv4 address space (equal to 16.8 million addresses).

3. Will the Internet still work when there are no IPv4 addresses left?

Yes. The Internet will continue to work and the IPv4 addresses already in use will continue to function.

4. Why can’t we just create more IPv4 addresses?

IPv4 allows for a maximum of just over four billion unique addresses (for example: It is limited by the number of unique number combinations that can be created in this format.

5. Can I still get IPv4 address space from my RIR?

As of 2018, four of the five RIRs have exhausted their own IPv4 pools and can now only allocate small amounts of IPv4 address space to new members in accordance with community-developed regional policies. Contact your local RIR to find out more about its IPv4 distribution policies and how to get an IPv6 allocation.

6. What is IPv6?

To account for the massive expansion in Internet-enabled services and devices, a new system of addressing had to be introduced to ensure enough unique IP addresses were available. The Internet Engineering Task Force (IETF) developed the new protocol, IPv6, which allows for 2128, or roughly 340 trillion trillion trillion, unique IP addresses. IPv6 addresses are 128-bit addresses, expressed in hexadecimal notation (for example: 2001:DB8:8::260:97ff:fe40:efab).

This huge number of addresses is expected to accommodate the predicted expansion of the Internet and Internet-related services well into the future. IPv6 was introduced in 1999 and has been in use ever since. This means that the core standards are stable and have been extensively tested in research and operational contexts.

7. I am an Internet user. How will IPv4 exhaustion affect me?

Internet users won’t notice the effect of IPv4 depletion in the foreseeable future. However, in the future there might be parts of the Internet that you cannot reach if the website or service is an IPv6-only network and your Internet Service Provider (ISP) does not provide its customers with IPv6 addresses.

8. Where can I find out more?

Find out more about IPv4 exhaustion on your local RIR’s website:



Last modified on 09/09/2020