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What is IPv4 Run Out?

Since the RIPE NCC began operations in 1992, we have been responsible for distributing IP addresses and AS Numbers in our service region. In November 2019, we exhausted our remaining IPv4 pool. This means that networks in Europe, the Middle East and parts of Central Asia are no longer able to receive “new” IPv4 addresses from us that haven’t previously been used by another network.

A shortage of IPv4 addresses can create a lot of problems for a network that is looking to grow or add new users. Many networks today are attempting to mitigate this scarcity by acquiring surplus addresses from other networks via the IPv4 transfer market, or by deploying address sharing technologies such as CGNAT. While these approaches may make sense in the immediate term, neither one solves the underlying problem – which is that there are not enough addresses in IPv4 to support an Internet that is as large as the one we have today.

IPv4 run-out does not come as a surprise to the technical community – it has long been anticipated and planned for. However, despite the great progress made with IPv6 deployment around the world, there is still some way to go. It is important that all stakeholders are aware of the likely impacts that run-out will have on individual networks as well as the wider Internet. Everyone has a part to play in supporting the deployment of IPv6, which is the best long-term solution to the problems created by IPv4 exhaustion.

How Have IPv4 Allocations Changed Over Time?

For most of the time that we have been a Regional Internet Registry, LIRs could receive as many IPv4 addresses as they needed. The only requirement was that they had to supply documentation such as network plans to prove that they needed the addresses.

This changed when we reached our last block of 16 million IPv4 addresses in 2012 (called a /8). This triggered a new policy that had been developed by the RIPE community which caused us to begin allocating addresses on a much more restricted basis. Under this policy all LIRs were able to request one single /22 IPv4 allocation (1,024 addresses). The allocation of the last remaining addresses in our available pool in November 2019 was the end of this period of limited allocations, and triggered the current waiting list policy. All LIRs that have not yet received an IPv4 allocation can now request a single /24 from addresses that we recover in the future.

The table below shows some of the changes since we reached the last /8.

When Date How IPv4 Requests Are Processed

When we have less than one /8 block of IPv4 addresses remaining


Each LIR can receive one /22 IPv4 allocation in the form of a single prefix

Once we have no more /22 prefixes


Each LIR can receive one /22 IPv4 allocation in the form of multiple smaller prefixes (/23s and/or /24s)

Once all available IPv4 address space is exhausted


LIRs can enter a waiting list to receive one /24 IPv4 allocation when addresses are returned in the future