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.
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, who.int for the World Health Organisation.
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.
Root Key Signing Key
The Root Key Signing Key is managed by ICANN to provide for verification of the DNSSEC-signed root zone.
Special Purpose Domains
A number of special domains are reserved or managed for demonstration purposes, or for future use.