Domain Name Services Domains Protocols Numbers About Domain Name Services We operate and maintain a number of key aspects of the DNS, including the root zone, and the .int and .arpa domains. The DNS Root Zone 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. .INT 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. .ARPA The .arpa domain is used internally by Internet protocols for purposes not designed to be directly accessed, as defined in various technical standards. IDN Practices Repository A repository of permissible characters for different languages and writing systems provided for registration by different domain registries, helping to foster internationalization. Root Key Signing Key (DNSSEC) The Root Key Signing Key provides verification of the DNSSEC-signed root zone, administered through public key signing ceremonies and serving as the DNS trust anchor. Reserved Domains Specially designated domains that are held to serve specialized purposes, such as avoiding conflicts with potential real-world usage. Domain Names Overview Root Zone Management Overview Top-Level Domains Files and Downloads Manage Delegations Instructions & Guides .INT Registry Overview Register/modify an .INT domain Eligibility .ARPA Registry IDN Practices Repository Overview Submit a table Root Key Signing Key (DNSSEC) Overview Trust Anchors and Rollovers Key Signing Ceremonies Policies & Procedures Community Representatives Reserved Domains Domain Names Root Zone Registry .INT Registry .ARPA Registry IDN Repository Number Resources Number Registries RIR Allocation Data Abuse Information Protocols Protocol Registries Time Zone Database About Us News Performance The Organization Archive Contact Us The IANA functions coordinate the Internet’s globally unique identifiers, and are provided by Public Technical Identifiers, an affiliate of ICANN. Privacy Policy Terms of Service