Internet Assigned Numbers Authority: Meaning (information, definition, explanation, facts)

The Internet Assigned Numbers Authority (IANA) is an organisation that oversees IP address, top level domain and Internet protocol code point allocations. IANA was formerly one man, the late Jon Postel.

IANA delegates local registrations of IP addresses to Regional Internet Registries (RIRs). Each RIR allocates addresses for a different area of the world namely:

• ARIN for North America
• RIPE NCC for Europe
• APNIC for Asia and the Pacific region
• LACNIC for Latin America and the Caribbean region

Currently Africa is divided between the four existing RIRs, though there is an emerging registry for the region, AfriNIC. It has not yet been fully ratified by the IANA, though looks likely to be so in the near future.

• AfriNIC for Africa

Collectively the RIRs form part of the Numbers Resource Organization(NRO), formed as a body to represent their collective interests and ensure that policy statements are co-ordinated globally.

IANA delegates the allocation of IPv4 addresses to RIRs in large chunks (typically /8 or more at a time), and the RIRs then follow their own policies for address allocation. They typically further delegate address assignment to ISPs in small chunks, such as /19 and /20s.

There is also a process for the delegation and allocation of IPv6 addresses, but there is currently little delegation pressure on blocks of IPv6 addresses, as supply vastly exceeds demand.

IANA is under the control of ICANN, but ultimate control of the DNS root zone is held by the United States Department of Commerce.

On January 28, 2003 the United States Department of Commerce, via the Acquisition and Grants Office of the National Oceanic and Atmospheric Administration, issued a notice of intent to grant ICANN control of IANA for up to three more years. It invited alternative offerors to submit in writing a detailed response on how they could meet the requirements themselves. Such responses were to be received no later than 10 days following publication of the invitation and the decision on whether to open the "tender" to competition was to remain solely within the discretion of the government.

The relationship between ICANN and the ccTLDs and RIRs can best be described as highly political, and there have been a number of proposals to decouple the IANA function from ICANN completely, with or without the cooperation of the U.S. government.

See also:

• CIDR
• BGP
• Routing
• DNS
• IPv4 address exhaustion
• List of well-known ports (computing)