The Internet Assigned Numbers Authority (IANA) is responsible for the global coordination of the DNS Root, IP addressing, and other Internet protocol resources. Following the IANA Stewardship Transition in 2016, the IANA function is carried out by Public Technical Identifiers (PTI), a purpose-built organisation wholly owned by ICANN.
With regard to Internet number resources, IANA's role is to allocate IP addresses and AS Numbers from the pools of unallocated resources to the Regional Internet Registries (RIRs) according to their needs, and to document protocol assignments made by the IETF. When an RIR requires more IP addresses for allocation or assignment within its region, IANA makes an additional allocation to the RIR. The five Regional Internet Registries have a Service Level Agreement with ICANN regarding provision of those IANA functions relating to Internet number resources (IP addresses and AS Numbers).
IANA does not make allocations directly to ISPs or End Users except in specific circumstances, such as allocations of multicast addresses or other protocol-specific needs.
The policies under which the IANA role is carried out are referred to as Global Addressing Policies, and must be agreed to by all of the five RIR communities. Any new policy proposal must go through the Policy Development Process in each RIR and be ratified by each community, and this process will then be reviewed by the ASO Address Council (ASO AC) before the new global policy is adopted.
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On 1 September 2017, the RIPE NCC and the other Regional Internet Registries (RIRs) were each allocated the equivalent of a /20 of IPv4 address space from the Internet Assigned Numbers Authority (IANA).
On 1 March 2017, the RIPE NCC and other Regional Internet Registries (RIRs) were each allocated the equivalent of a /19 of IPv4 address space from the Internet Assigned Numbers Authority (IANA).
From today, the RIPE NCC performs registry functions for IPv6 Endpoint ID (EID) prefixes for Locator/Identifier Separation Protocol (LISP). LISP is an experimental "map-and-encapsulate" protocol developed by the Internet Engineering Task Force's (IETF's) LISP Working Group. The IANA has assigned an IPv6 prefix for LISP EID space in accordance with RFC7954, which the RIPE NCC is now managing in accordance with RFC7955.
On 1 October 2016, the IANA functions contract that the United States Government had with ICANN was allowed to expire. This represents the final step in the community-led IANA stewardship transition process that began in 2014. Oversight of IANA is now the responsibility of the Names, Numbers and Protocol Parameters communities that rely on its services.
On 1 September 2016, the RIPE NCC and other Regional Internet Registries (RIRs) were each allocated the equivalent of a /18 of IPv4 address space from the Internet Assigned Numbers Authority (IANA).