IPv6 11 September 2015

A Short Guide to IP Addressing

How are IP addresses managed and distributed?

IP addresses are managed by the Internet Assigned Numbers Authority (IANA), which has overall responsibility for the Internet Protocol (IP) address pool, and by the Regional Internet Registries (RIRs) to which IANA distributes large blocks of addresses.

The RIRs manage, distribute, and publicly register IP addresses and related Internet number resources, such as Autonomous System Numbers (ASN) and reverse Domain Name System (DNS ) delegations within their respective regions. They do this according to policies which are developed within their respective regional communities, through open and bottom-up processes.

There are currently five RIRs:

  1. AfriNIC – African region
  2. APNIC – Asia Pacific region
  3. ARIN – North America and several Caribbean and North Atlantic islands
  4. LACNIC – Latin America and the Caribbean
  5. RIPE NCC – Europe, the Middle East, and parts of Central Asia

The five RIRs together also form the Number Resource Organization (NRO), which carries out joint activities of the RIRs, including joint technical projects, liaison activities, and policy co-ordination. For more background on IP address management visit:

How are IPv6 addresses allocated?

Both IPv4 and IPv6 addresses are allocated to those who show that they need addresses for their networks.

Shouldn’t addresses be allocated on a geographical basis to ensure that distribution is equitable?

For technical reasons the allocation of IP addresses has to follow the topology of the network and not geography or national borders.

Therefore, the addresses are allocated for use in specific networks, as they are required. RIRs allocate IP addresses  using community-developed policies that are designed to ensure that distribution is fair and equitable.

In the early days of the Internet, the method for distributing IP addresses was less formal, resulting in some organisations receiving disproportionately large address ranges.

The RIRs were formed to provide a better way of distributing addresses. They have been successful at developing fair and equitable distribution policies. They have also helped to provide stability of the address pool and routing tables throughout a long period of rapid growth.

What happens when IPv4 addresses run out?

The Internet, in its current form, already has. According to the Number Resource Organization, the world officially ran out of IPv4 addresses in February 2011.

The only option now is to divide the allocated properties into smaller portions or to start trading what’s already been assigned – both moves could complicate and compromise your privacy.

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