IPv4 Depletion and IPv6 Deployment

We've split this information into:

• General information about IPv4 exhaustion and IPv6 deployment
• Information about IPv4 exhaustion and IPv6 deployment for network operators, Internet Service Providers (ISPs) and Local Internet
  Registries (LIRs)
  

General information about IPv4 exhaustion and IPv6 deployment

1. What is meant by IPv4 exhaustion?
2. When the IPv4 pool is exhausted, will the Internet stop working?
3. When are IPv4 addresses going to run out?
4. How will the IANA distribute the final blocks of IPv4 address space to the RIRs?
5. Why is the IPv4 address pool facing exhaustion?
6. Can more IPv4 addresses be added to the available pool?
7. Why is IPv4 exhaustion a 'hot topic' when there are plenty of IPv6 addresses that can be used instead?
8. What are the stages of IPv4 exhaustion?
9. I am an Internet user. How will IPv4 exhaustion affect me?
10. What is IPv6?
11. Are there different policies for allocating IPv6 addresses and IPv4 addresses?

1. What is meant by IPv4 exhaustion?

The "pool" of available IPv4 addresses is almost empty. IPv4 addresses are 32-bit numerical addresses, for example, 10.142.131.235. There are 2³², or just over four billion, unique IPv4 addresses. As of 2009, most of these four billion IPv4 addresses had been allocated for use or reserved for a specific technical purpose.

2. When the IPv4 pool is exhausted, will the Internet stop working?

No. The exhaustion of the IPv4 free pool does not mean that the Internet will cease to work. All of the IPv4 addresses that are in use will still operate as they always have.

3. When are IPv4 addresses going to run out?

It is not possible to state a specific date for IPv4 exhaustion because future allocation and request rates can only be estimated. However, experts predict that the supply of available IPv4 addresses will run out in 2011 or 2012. One of the Internet industry's leading authorities on IPv4 exhaustion, Geoff Huston, Chief Scientist at APNIC, the RIR for the Asia Pacific region, tracks IPv4 allocation and depletion rates at:
http://www.potaroo.net/tools

4. How will the IANA distribute the final blocks of IPv4 address space to the RIRs?

The Internet Assigned Numbers Authority (IANA) will distribute the final blocks of IPv4 address space to the five Regional Internet Registries (RIRs) according to a global distribution policy that all five RIR communities decide upon.

Policy proposals concerning the distribution of the final blocks of IPv4 address space are currently under discussion. Any policy regarding this will be a global policy and will require the consensus of all five RIR communities.

To provide your input for this, and for any other policy proposal, you can take part in the RIPE Policy Development Process (PDP).

5. Why is the IPv4 address pool facing exhaustion?

The unprecedented expansion of the Internet was simply not predicted when the IPv4 standard was adopted. As more and more users connect to the Internet and more devices are Internet-enabled, more IP addresses need to be used.

6. Can more IPv4 addresses be added to the available pool?

No. The way IPv4 addresses are formulated (for example 10.142.131.235) allows for a maximum of 2³², or just over four billion, unique IPv4 addresses. 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. See What is IPv6 for more information.

7. Why is IPv4 exhaustion a 'hot topic' when there are plenty of IPv6 addresses that can be used instead?

IPv4 addresses and IPv6 addresses can't communicate directly with each other. So, before IPv6 addresses can be used to access the Internet, networks, services and products need to be IPv6 compatible or enabled. This requires the investment of time, money and training. Some network operators are not prioritising the need to invest in the new hardware and software required to make their networks IPv6-ready. As the pool of available IPv4 addresses gets smaller, the RIRs and other industry partners are increasing their efforts to ensure that everyone is aware of IPv4 exhaustion and the importance of preparing for the widespread adoption of IPv6 on the Internet.

8. What are the stages of IPv4 exhaustion?

There are three key stages in the process of IPv4 exhaustion:

• Stage 1: The Internet Assigned Numbers Authority (IANA) will run out of unused IPv4 address space to allocate to the five RIRs
• Stage 2: The RIRs will run out of unused IPv4 address space to allocate to their members
  
• Stage 3: Local Internet Registries (LIRs) that are using IPv4 space already allocated to them from the RIRs will run out of unused IPv4 address space to assign to their customers (End Users)

The RIPE NCC will keep its members and the RIPE community informed during every stage of IPv4 exhaustion.

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

As a user of the Internet, you will not really notice the effect of IPv4 exhaustion for the foreseeable future. It will not make any significant difference to you whether you access the Internet using an IPv6 or an IPv4 address. However, in the future there may be parts of the Internet that you cannot reach if the destination is an IPv6-only network and your ISP does not provide its customers with IPv6 addresses.

10. What is IPv6?

Internet Protocol version 6 (IPv6) was designed by the Internet Engineering Task Force (IETF) to expand the amount of IP addresses available. IPv6 addresses are 128-bit addresses, expressed in hexadecimal notation (for example, 2001:DB8:8::260:97ff:fe40:efab).

There are 2¹²⁸ IPv6 addresses, or roughly 340 trillion, trillion, trillion. This huge amount of addresses is expected to accommodate the predicted expansion of the Internet and Internet-related services over the coming years.

IPv6 was introduced in 1999 and has been in use since then. This means that the core standards are stable and have been well tested in research and operational contexts.

11. Are there different policies for allocating IPv6 addresses and IPv4 addresses?

Yes. Technical differences between IPv4 and IPv6 mean that there are different policies for IPv4 and IPv6 address space management and assignment. See Do the IPv6 address assignment policies differ from the IPv4 address assignment policies for more information.

Information about IPv4 exhaustion and IPv6 deployment for network operators, Internet Service Providers (ISPs) and Local Internet Registries (LIRs)

1. Can I buy an IPv4 address allocation from another organisation if I cannot get it from an RIR anymore?
2. Can IPv4 address space be transferred between address space holders?
3. What should I do now to prepare for the exhaustion of IPv4 addresses?
4. What will happen when the RIRs have no more IPv4 addresses to allocate and my network is not IPv6 ready?
5. There are not that many IPv6 compatible products on the market. Will this change?
6. Can IPv4 and IPv6 be used in parallel?

1. Can I buy an IPv4 address allocation from another organisation if I cannot get it from an RIR anymore?

All IP addresses are regarded as a public resource and cannot be bought or sold. However, the transfer of IPv4 address space between RIPE NCC members is possible. See Can IPv4 address space be transferred between address space holders?

2. Can IPv4 address space be transferred between address space holders?

IPv4 address space can be transferred between RIPE NCC members according to the terms stated in "IPv4 Address Allocation and
Assignment Policies for the RIPE NCC Service Region".

3. What should I do now to prepare for the exhaustion of IPv4 addresses?

• Content providers should prepare networks so that they are accessible using IPv6 as well as IPv4.
• Network operators should ensure that their networks are IPv6 enabled and can be used by their customers to access other IPv6 networks.
• Software producers should ensure that that their software is IPv6 compliant.
• Hardware vendors should ensure that their products are IPv6 compatible.
  

4. What will happen when the RIRs have no more IPv4 addresses to allocate and my network is not IPv6 ready?

At a certain point in the future, the RIRs will not have any new IPv4 addresses to allocate. Only IPv6 addresses will be available for the RIRs to allocate.

There is no way for IPv4-only and IPv6-only networks to directly communicate with each other. However, various technologies which ensure the interoperability of IPv4 and IPv6 networks. These technologies include "tunnelling", which enables IPv6 packets to be moved across the core of the IPv4 network, and "dual stacking", which enables an Internet host to provide two discrete network layers, one running IPv4 and the other IPv6. Find out more information about some of the available technologies at:
Teredo
6to4

If you have an IPv4-only network, you will need to use such technologies to reach IPv6-only networks. Those with IPv6-only networks will need to use these technologies to reach IPv4-only networks.

5. There are not that many IPv6 compatible products on the market. Will this change?

Widespread adoption of IPv6 relies on strong demand from customers to encourage their vendors to provide an increasing range of IPv6-enabled products and services. While IPv6 hardware and software products are becoming increasingly available, there are still many products on the market and in circulation that are not IPv6 compatible. It is expected that this will change as IPv6 traffic increases.

6. Can IPv4 and IPv6 be used in parallel?

Yes. There will be a period during which many organisations will run IPv4 and IPv6 networks in parallel. IPv6 and its transition mechanisms have been designed to take co-existence with IPv4 into account.

Various technologies exist to ensure that traffic can move between IPv4 and IPv6 networks. These technologies include "tunnelling", which enables IPv6 packets to be moved across the core of the IPv4 network, and "dual stacking", which enables an Internet host to provide two discrete network layers, one running IPv4 and the other IPv6. Find out more information about some of the available technologies at:
Teredo
6to4