Internet Assigned Numbers Authority (IANA)

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Definition of Internet Assigned Numbers Authority (IANA) in The Network Encyclopedia.

What is IANA (Internet Assigned Numbers Authority)?

IANA (Internet Assigned Numbers Authority) is a U.S. government-funded organization that coordinates the assignment of unique Internet protocol parameters such as the IP address space and the Domain Name System (DNS).

IANA - Internet Assigned Number Authority
IANA – Internet Assigned Number Authority

The Internet Assigned Numbers Authority (IANA) also delegates authority to other organizations and companies to grant users unique IP address blocks and register domain names. IANA is the ultimate authority for managing the root name servers that maintain the central database of information for the DNS.

IANA also controls the assignment of TCP/IP protocol identifiers and numbers for autonomous systems on the Internet.

IANA operates under the auspices of the Internet Society (ISOC). It is also considered part of the Internet Architecture Board (IAB). IANA delegates the responsibilities for managing IP and DNS space to three regional bodies:

  • The American Registry for Internet Numbers (ARIN), which manages North America, South America, and sub-Saharan Africa
  • Réeseaux IP Européens (RIPE), which manages Europe and North Africa
  • The Asia Pacific Network Information Center (APNIC), which manages Asia and Australia

A new international nonprofit organization called the Internet Corporation for Assigned Names and Numbers (ICANN) will eventually take over the responsibilities of IANA because of the increasingly international and commercial nature of the Internet. ICANN will open up the registration and management of the DNS to commercial companies.


Actual registration of IP addresses and DNS names is performed by network information centers, of which there are currently four in the United States:

  • Internet Network Information Center (InterNIC), which has exclusive authority over registering .com, .org, .net, .gov, and .edu top-level domains
  • The U.S. Domain Registration Service, which administers the .us top-level domain
  • The U.S. Department of Defense Network Information Center, which manages the .mil top-level domain
  • The .int top-level domain registry in Marina del Ray, California

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