Internet Assigned Numbers Authority (IANA)

IANA coordinates critical global Internet identifiers: DNS root management, IP address allocations, protocol registries and other numeric or symbolic constants. It operates within ICANN and serves interoperable operations.

Overview

The Internet Assigned Numbers Authority (IANA) is the central coordinator for a variety of core Internet identifiers and protocol values. It performs operational functions that keep the Domain Name System (DNS), Internet Protocol (IP) addressing, and many protocol parameter lists consistent and globally interoperable. IANA operates as an organizational function within ICANN, carrying out technical registry work that the global Internet depends on.

Primary functions

IANA maintains and publishes authoritative registries and manages global coordination tasks. Major areas of responsibility include:

DNS root zone management, including delegation of top-level domains (TLDs) and coordination of changes to the root zone.
Allocation of global IP address blocks and autonomous system (AS) numbers, allocated to regional Internet registries for distribution.
Management of protocol parameter registries used by standards bodies such as the IETF (for example, port numbers, protocol numbers and other assigned constants).
Maintenance of timezone and other standardized databases used by software and systems worldwide.

How it works

IANA typically acts on requests from standards organizations, network operators or regional registries and follows published policies and procedures to make updates. For IP address allocations it works with the five Regional Internet Registries (RIRs) that distribute space to local networks. For DNS and protocol values it implements changes after verification and community review, ensuring a single authoritative source of truth.

History and governance

The IANA function traces back to early Internet engineering coordination and the stewardship of key technical registries. The operational role was later institutionalized within ICANN. Historically the U.S. government had a stewardship relationship with IANA; in 2016 oversight transitioned to a broader global multistakeholder model. Today IANA is performed as an ICANN-managed service within a framework of community-developed policies and contractual commitments, and ICANN is organized as a nonprofit corporation.

Importance and notable points

Because IANA provides a single, authoritative source for names, numbers and protocol values, its work is essential to ensure that independent networks and software can interoperate worldwide. Changes it makes—such as delegating a new TLD, assigning a block of IPv6 addresses, or publishing a new protocol port number—affect routing, name resolution and software compatibility across the global Internet.