IANA is a standards organization owned by ICANN responsible for global allocation of IP Addresses and ASNs, management of DNS root zones, and protocol assignments. In regards to IP number management, IANA is primarily responsible for allocating a pool of unallocated IP blocks to RIRs according to the global policy to ensure fair allocation of IP addresses across the regions.

IANA also manages root zone of DNS for ccTLDs and gTLDs, and maintain a database of all Top Level Domains (TLDs). In addition to IP number management and DNS root zone management, IANA also works with ITEF (Internet Engineering Task Force) to maintain a central repository for protocol names and number registries used in IP protocols (protocol assignments). IANA also maintains a time zone database and allows computers and electronic devices to use this information to maintain the correct time zone around the world.

Think of IANA as the administrator of the Internet. It manages domain names, IP addresses & ASNs, and protocols used by the Internet. The goal of IANA is to help the Internet run smoothly.

IP number allocation

The allocation of IP addresses is done by RIRs, and the the assignment is reported to IANA for record-keeping purposes. The global management of domain names and IP numbers is done by ICANN, and ICANN delegates management of Internet Numbers (IP Addresses and ASNs) to IANA which is a sub-organization of ICANN. IANA then delegates the assignment of Internet numbers to 5 Regional Internet Registries (RIRs). Five RIRs include ARIN (North America), AFRINIC (Africa), APNIC (Asia Pacific), LACNIC (Latin America), and RIPENCC (Europe). IANA and RIRs are making sure that unique IP address blocks are assigned to an organization within each of the 5 regional groups.

Dealing with IP Address Abuse

People often report spamming, hacking attempts, and other forms of IP address abuses to IANA. The IP address abuse should be reported to the organization that owns (assigned) the IP address, not IANA. You may use ARIN's WHOIS Lookup tool to query IP address ownership, and find the abuse contact information. IANA is a record keeper of the Internet Numbers (IP address and ASN), and it does not resolve matters relating to IP address abuses.

Protocol Assignments

IANA cooperates with the ITEF to define protocol standards which include network protocols and their parameters. The common network parameters include but not limited to:

• Port numbers: Along with an IP address, the TCP and UDP ports are defined to allow applications to communicate with each other within the TCP/IP network.
• HTTP Status Codes: When a web client makes a HTTP request, the server respond with the response with HTTP status code to indicate whether the request has been processed successfully, or errored with a reason code.
• Media Types: IANA maintains media type registry that can be used within the Internet.

Besides protocol numbers, IANA also maintains 2-letter language attributes (en: English, es: Spanish, and etc.), private enterprise numbers, and time zone database among others.