What is IANA?
IANA (Internet Assigned Numbers Authority) is the organization responsible for coordinating the global allocation of critical internet resources. These include the DNS root zone, IP address allocation, and protocol parameter assignments. Operating under ICANN since 1998, IANA ensures the stable and secure operation of the internet's unique identifier systems that enable global communication.IANA's core responsibilities
1. DNS root zone management
- Maintains the authoritative root zone file
- Coordinates TLD delegations to registries
- Processes root zone change requests
- Manages root server letter assignments (a.root-servers.net through m.root-servers.net)
2. IP address allocation
- Allocates IP blocks to Regional Internet Registries (RIRs)
- Manages IPv4 and IPv6 address space
- Coordinates special-purpose address assignments
- Maintains global address allocation policies
3. Protocol parameters
- Assigns port numbers (HTTP=80, HTTPS=443)
- Manages protocol identifier registries
- Coordinates with IETF on new assignments
- Maintains official parameter registries
IANA and the DNS hierarchy
IANA (Root Zone Management)
│
├── .com Registry (Verisign)
│ └── Registrars → Domain owners
│
├── .org Registry (PIR)
│ └── Registrars → Domain owners
│
├── .uk Registry (Nominet)
│ └── Registrars → Domain owners
│
└── Other TLDs...
Regional Internet registries (RIRs)
IANA allocates IP address blocks to five RIRs:
| RIR | Region | Coverage |
|---|---|---|
| ARIN | North America | US, Canada, Caribbean |
| RIPE NCC | Europe | Europe, Middle East, Central Asia |
| APNIC | Asia-Pacific | Asia, Australia, Pacific |
| LACNIC | Latin America | Central/South America, Caribbean |
| AFRINIC | Africa | All African nations |
IANA databases and registries
Root zone database
Lists all TLDs with their registry operators, nameservers, and DNSSEC status.
WHOIS service
Provides authoritative TLD registration information:
whois -h whois.iana.org .comProtocol registries
- Port number assignments
- Media types (MIME types)
- Character sets
- HTTP status codes
- URI schemes
Key IANA functions
TLD delegation
When a new TLD is created:
1. Application submitted to ICANN
2. Technical evaluation completed
3. IANA coordinates root zone update
4. TLD begins resolving globally
Root zone updates
- Changes processed via automated system
- Cryptographically signed with DNSSEC
- Distributed to root servers worldwide
- Typically propagate within 24-48 hours
IANA stewardship transition
In 2016, IANA stewardship transitioned from US government oversight to the global multistakeholder community:
- NTIA contract with ICANN ended
- New accountability mechanisms established
- Global community oversight implemented
- Operational continuity maintained
Accessing IANA resources
| Resource | URL |
|---|---|
| Root Zone Database | iana.org/domains/root/db |
| TLD WHOIS | whois.iana.org |
| Protocol Registries | iana.org/protocols |
| Time Zone Database | iana.org/time-zones |
IANA remains the foundational coordination body ensuring the internet's naming and numbering systems operate consistently and securely across the global network.