.arpa Infrastructure TLD
Address and Routing Parameter Area
The .arpa top-level domain is one of the original TLDs, created in 1985 to support critical internet infrastructure functions. It is not used for public website registration but instead hosts reverse DNS lookups and other network protocol mappings, such as translating IP addresses into domain names.
Not available for public registration. Used exclusively for infrastructure purposes by network operators and protocol standards bodies.
.arpa Domain Overview
The .arpa extension is a infrastructure top-level domain in the Domain Name System (DNS). It is managed by Internet Assigned Numbers Authority (IANA). .arpa was introduced in 1985.
Registration Info
Registration pricing for .arpa is not publicly listed. Contact an ICANN-accredited registrar for availability and pricing.
Security Features
- DNSSEC
What Is the History of .arpa?
The .arpa domain was originally created in 1985 as a temporary transition mechanism for hostnames from the ARPANET. Although the plan was to phase it out after introducing .com, .edu, .net, and others, key infrastructure functions like reverse DNS (in-addr.arpa and ip6.arpa) remained essential. In 2000, the Internet Architecture Board (IAB) formally re-designated .arpa as the permanent namespace for Internet infrastructure, prohibiting new infrastructure domains under .int and mandating that all future protocol-related domains be allocated under .arpa.
Did you know?
The .arpa TLD serves a specific purpose in the domain ecosystem, providing users with clear context about the websites using this extension.
What Is .arpa Used For?
The .arpa TLD is commonly used for the following purposes:
Reverse DNS lookups for IPv4 (in-addr.arpa)
Reverse DNS lookups for IPv6 (ip6.arpa)
Mapping E.164 telephone numbers to URIs (e164.arpa)
Discovering Internet Registry Information Services (iris.arpa)
Resolving Uniform Resource Identifiers (uri.arpa)
Resolving Uniform Resource Names (urn.arpa)
How Do I Register a .arpa Domain?
Eligibility
Not applicable. Registration is prohibited for public or private entities. Only IANA, under IAB direction, may delegate subdomains for protocol-specific infrastructure use.
Open Registration
The .arpa TLD is available for registration through accredited domain registrars.
Registration Process
- Choose an accredited domain registrar that offers .arpa domains
- Check domain availability using the registrar's search tool
- Complete the registration process and provide required information
- Pay the registration fee (typically )
- Manage your domain settings through your registrar's control panel
Frequently Asked Questions
How Is This .arpa Data Compiled?
DNS Checker maintains a comprehensive TLD directory covering all 1,900+ active top-level domains. The data on this page combines multiple authoritative sources to provide information not found in standard TLD listings.
Zone File Analysis
Domain registration counts and density analysis are computed daily from TLD zone files, providing accurate registration statistics rather than estimates.
DNSSEC Adoption Tracking
DNSSEC deployment percentages are measured by scanning actual DNS records across all registered domains in each TLD zone.
Registrar Price Monitoring
Registration, renewal, and transfer prices are checked hourly across multiple accredited registrars and compared automatically.
Provider Market Share
DNS provider distribution is calculated from nameserver records, showing which hosting providers serve the most domains in each TLD.
Use DNS Checker tools to inspect any .arpa domain: run a full DNS health check, check DNS propagation, look up WHOIS records, or verify email authentication.
Disclaimer: The information on this page is sourced from IANA, ICANN, and respective registry operator publications, then structured and formatted with the assistance of AI. While accuracy is a priority, details such as pricing, registration requirements, and policies may change. Always verify with the official registry or an accredited registrar before making registration decisions.