Root Zone Management

IANA is responsible for management of the DNS root zone. This role means assigning the operators of top-level domains, such as .UK and .COM, and maintaining their technical and administrative details.

Browse

IANA's Root Zone Database contains the authoritative record of the operators of various top-level domains.

• Root Zone Database

Maintain

TLD operators can change their delegation details by submitting revised details using the template.

• Root zone change template

Policy, Procedures and Guides

• Country Code Top Level Domains
  Including information on routine updates from ccTLD Managers, as well as processes for delegation and redelegation of ccTLDs.
• Domain Name System Structure and Delegation (RFC 1591, March 1994)
• Internet Domain Name System Structure and Delegation (ICP-1, May 1999)

Number Resources

IANA is responsible for global coordination of the Internet Protocol addressing systems, as well as the Autonomous System Numbers used for routing Internet traffic.
Currently there are two types of Internet Protocol (IP) addresses in active use: IP version 4 (IPv4) and IP version 6 (IPv6). IPv4 was initially deployed on 1 January 1983 and is still the most commonly used version. IPv4 addresses are 32-bit numbers often expressed as 4 octets in "dotted decimal" notation (for example, 192.0.2.53). Deployment of the IPv6 protocol began in 1999. IPv6 addresses are 128-bit numbers and are conventionally expressed using hexadecimal strings (for example, 2001:0db8:582:ae33::29).
Both IPv4 and IPv6 addresses are generally assigned in a hierarchical manner. Users are assigned IP addresses by Internet service providers (ISPs). ISPs obtain allocations of IP addresses from a local Internet registry (LIR) or National Internet Registry (NIR), or from their appropriate Regional Internet Registry (RIR):

Registry Area Covered AfriNIC Africa Region APNIC Asia/Pacific Region ARIN North America Region LACNIC Latin America and some Caribbean Islands RIPE NCC Europe, the Middle East, and Central Asia

The IANA's role is to allocate IP addresses from the pools of unallocated addresses to the RIRs according to their needs as described by global policy and to document protocol assignments made by the IETF. When an RIR requires more IP addresses for allocation or assignment within its region, the IANA makes an additional allocation to the RIR. We do not make allocations directly to ISPs or end users except in specific circumstances, such as allocations of multicast addresses or other protocol specific needs.

IP Address Allocations

Internet Protocol Version 4 (IPv4)

• Internet Protocol v4 Address Space
• Internet Protocol v4 Multicast Address Assignments
• IANA IPv4 Special Purpose Address Registry

Internet Protocol Version 6 (IPv6)

• Announcement of Worldwide Deployment of IPv6 (14 July 1999)
• RIR Comparative Policy Overview
• IPv6 Address Space
• IPv6 Global Unicast Allocations
• IPv6 Parameters (Parameters described for IPv6, including header types, action codes, etc.)
• IPv6 Anycast Address Allocations
• IPv6 Multicast Address Allocations
• IPv6 Sub-TLA Assignments (DEPRECATED)
• IANA IPv6 Special Registry

Autonomous System Number Allocations

• Autonomous System Numbers

Emerging Regional Internet Registries

• Criteria for Establishment of New Regional Internet Registries (ICP-2) (4 June 2001)
• IANA Report on Recognition of LACNIC as a Regional Internet Registry (7 November 2002)
• IANA Report on Recognition of AfriNIC as a Regional Internet Registry (8 April 2005)

Technical Documentation

• RFC 4632 — Classless Inter-domain Routing (CIDR): The Internet Address Assignment and Aggregation Plan
• RFC 1918 — Address Allocation for Private Internets
• RFC 2050 — Internet Registry IP Allocation Guidelines
• RFC 5735 — Special-Use IPv4 Addresses
• RFC 5736 — IANA IPv4 Special Purpose Address Registry
• RFC 5737 — IPv4 Address Blocks Reserved for Documentation
• RFC 4291 — Internet Protocol Version 6 (IPv6) Addressing Architecture
• RFC 3587 — IPv6 Global Unicast Address Format
• RFC 3177 — IAB/IESG Recommendations on IPv6 Address Allocations to Sites
• RFC 5156 — Special-Use IPv6 Addresses

Introducing IANA

• About IANA
• Glossary
• Presentations
• Popular and Important Links
• Performance Reporting and Statistics
• Procedures
• Projects
• Reports
• About Jon Postel

The Internet Assigned Numbers Authority (IANA) is the body responsible for coordinating some of the key elements that keep the Internet running smoothly. Whilst the Internet is renowned for being a worldwide network free from central coordination, there is a technical need for some key parts of the Internet to be globally coordinated – and this coordination role is undertaken by IANA.
Specifically, IANA allocates and maintains unique codes and numbering systems that are used in the technical standards (“protocols”) that drive the Internet.
IANA’s various activities can be broadly grouped in to three categories:

• Domain Names
  IANA manages the DNS root, the .int and .arpa domains, and an IDN practices resource.
• Number Resources
  IANA coordinates the global pool of IP and AS numbers, providing them to Regional Internet Registries.
• Protocol Assignments
  Internet protocols’ numbering systems are managed by IANA in conjunction with standards bodies.

IANA is one of the Internet's oldest institutions, with its activities dating back to the 1970s. Today it is operated by the Internet Corporation for Assigned Names and Numbers, an internationally-organised non-profit organisation set up by the Internet community to help coordinate IANA's areas of responsibilities.

Mission Statement

This statement describes the role of the IANA Department:

The IANA team is responsible for the operational aspects of coordinating the Internet’s unique identifiers and maintaining the trust of the community to provide these services in an unbiased, responsible and effective manner.

IANA's Policy

IANA aims not to directly set policy by which it operates, instead implementing agreed policies and principles in a neutral and responsible manner. Using the policy setting forums provided by ICANN, policy development for domain name operations and IP addressing is arrived at by many different stakeholders. ICANN has a structure of supporting organisations that contribute to deciding how ICANN runs, and in turn how IANA develops. The development of Internet protocols, which often dictate how protocol assignments should be managed, are arrived at within the Internet Engineering Task Force, the Internet Engineering Steering Group, and the Internet Architecture Board.
To improve its operations, IANA is actively involved in outreach too. As well as in ICANN forums, IANA participates in meetings and discussions with TLD operators, Regional Internet Registries, and other relevant communities. The Authority provides a manned helpdesk at IETF meetings to allow one-to-one interaction with its largest community of users – protocol developers.

Domain Name Services

IANA is responsible for the operation and maintenance of a number of key aspects of the DNS, including the root zone, and the .int and .arpa domains.
The DNS Root Zone
IANA is the global coordinator of the DNS root. The root is the upper-most part of the DNS hierarchy, and involves delegating administrative responsibility of “top-level domains”, which are the last segment of a domain name, such as .com, .uk and .nz. Part of this task includes evaluating requests to change the operators of country code domains, as well as day-to-day maintenance of the details of the existing operators.
.INT
IANA operates the .int top-level domain, designed for the sole use of cross-national organisations, such as treaty organisations, that do not naturally fit into a specific country’s top-level domain. For example, the World Health Organisation uses who.int for its Internet presence, whilst NATO uses nato.int.
.ARPA
The .arpa domain is used internally by Internet protocols, such as for reverse mapping of IP addresses, and delivery of ENUM phone number mapping. IANA administers this domain in close liaison with the Internet Architecture Board, which has policy responsibility for .arpa.
IDN Practices Repository
To help foster the deployment of Internationalised Domain Names (IDNs), IANA provides a repository of “IDN tables” which document the permissable characters for different languages and scripts provided for registration by different top-level domain registries. The repository is informative, and designed for information sharing.
Interim Trust Anchor Repository
For early adopters of DNSSEC technology, IANA provides a repository of “trust anchors” from top-level domain operators who sign their zones. This allows software to cryptographically verify that DNS data has not been modified in transit over the Internet.