.in-addr.arpa domains list

What is .in-addr.arpa TLD

.in-addr.arpa is the Internet’s infrastructure domain for IPv4 reverse DNS, often treated as a top-level reference despite residing under .arpa. It maps numeric IP addresses back to hostnames using PTR records and is not intended for hosting conventional content. Consequently, queries about .in-addr.arpa domains and .in-addr.arpa websites describe technical delegations rather than public registrable spaces. In our index we currently observe 19 active domains and 0 live websites, reflecting its operational, not web-facing, role. Usage concentrates on network operations, logging, and reputation systems where reverse lookups are required for validation and troubleshooting. We monitor these delegations for stability, responsiveness, and structural changes across the global DNS. Download .in-addr.arpa domain datasets from webatla.

History and key features of .in-addr.arpa TLD

Historically, .in-addr.arpa emerged in the early Internet to support hierarchical reverse mapping of IPv4 space, administered within the ARPA infrastructure and standardized by IETF practice. Its key features include delegation by network blocks, PTR-based name resolution, and compatibility with DNSSEC where implemented. Because the space is operational rather than commercial, .in-addr.arpa domains evolve slowly and .in-addr.arpa websites are generally absent. Our crawl shows 0 new registrations last week and 0 in November 2025, consistent with low churn. We also record 0 countries where the TLD is used, reflecting its non‑country‑specific nature. These indicators help us benchmark stability, misconfiguration rates, and routing hygiene over time. Get the complete .in-addr.arpa datasets from webatla.

Why and who choose the .in-addr.arpa domain

Organizations that ‘choose’ .in-addr.arpa typically do so by maintaining reverse‑DNS zones: regional internet registries, ISPs, hosting providers, CDNs, enterprises, and security teams. The goal is verifiable IP‑to‑name mapping for email policy, threat intelligence, and operational forensics, not consumer branding. In this context, .in-addr.arpa domains function as technical delegations, while .in-addr.arpa websites are an edge case. Our current snapshot lists 19 active delegations, with 0 domains resolving with DNS records and 0 live websites, highlighting minimal web exposure. We analyze availability, PTR consistency, and nameserver topology to surface configuration drift and dependencies across networks. Explore .in-addr.arpa datasets now with webatla.