IPWHOISipwhois.info
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02 / FOLLOW THE SOURCE · 3 MIN READ

From an IP to Its Registry.

WHOIS is a familiar name. RDAP is the structured protocol this site uses to obtain network-registration information over HTTPS.

How a Lookup Travels

  1. Validate one IP. The input must be a public unicast IPv4 or IPv6 address. Domain names, URLs and CIDR input are not accepted by this tool.
  2. Select the service. The server reads IANA’s address-space routing data and chooses the supported registry with the most specific matching prefix.
  3. Request the record. The server queries that registry’s RDAP service. Supported referrals are followed only within the five reviewed registry services.
  4. Check and summarize. The result must be an IP network record whose range contains the requested address. The interface presents selected fields and the source URL.

Routing reference: Finding the authoritative RDAP service ↗. Published data: IANA IPv4 bootstrap registry ↗.

The Five Supported Registries

IPWHOIS can follow its reviewed RDAP endpoints for AFRINIC, APNIC, ARIN, LACNIC and RIPE NCC. The selected registry is shown in each result. This is a source-selection process, not a vote between five competing answers.

IP Registration Is Not Domain Registration

A hostname can point to an address operated by a hosting company or CDN. Looking up that IP describes the returned address registration, not the registrant of the hostname. Likewise, an IP network record is not the same thing as an autonomous-system registration or a current routing announcement.

The ARIN RDAP guide explains the different object and query types. This website exposes only its IP network summary endpoint.

Why an Answer Can Be Unavailable

There may be no supported route or record, a provider may be unavailable, or a referral may be outside the reviewed services. A timeout, rate limit or unsupported referral is shown as a limitation—not replaced with a guessed registry or an unrelated answer.

About the Ten-Minute Cache

Successful summaries can be reused from application memory for up to ten minutes. The cached label and original fetch time are shown together. Repeating the same query is not a way to force a refresh, and cached lookups still count against this site’s request budgets.