WHOIS (RADB)
We perform live WHOIS queries to the Route Arbiter Database (RADB) and authoritative internet registries for real-time IP address and ASN ownership information. Unlike pre-compiled databases that may be hours or days old, live WHOIS queries return the current registration state directly from the authoritative source. This data powers ownership information on robtex.com, rtsak.com, and dns.ninja.
Source:WHOIS (RADB)
What is WHOIS via RADB?
WHOIS is one of the oldest protocols on the internet (RFC 3912), providing a directory service for internet resource registrations. When you need to know who controls an IP address or AS number right now, a WHOIS query to the appropriate registry returns the authoritative answer.
The WHOIS ecosystem involves multiple registries:
- RADB (Route Arbiter Database) - Operated by Merit Network, RADB mirrors data from multiple registries and serves as a unified query point. It contains over a million objects from registries worldwide
- RIR WHOIS servers - Each Regional Internet Registry (ARIN, RIPE, APNIC, LACNIC, AFRINIC) operates authoritative WHOIS servers for resources they have allocated
- National registries - Some countries operate their own registries (e.g., JPNIC for Japan, KRNIC for Korea) with more detailed local information
A live WHOIS query for an IP address returns the registration record including the network block it belongs to, the organization that holds the allocation, abuse contacts, creation and modification dates, and the status of the allocation. For AS numbers, WHOIS returns the aut-num object with organization details, contacts, and routing policy.
The key advantage of live queries over static databases is immediacy. IP space transfers, organizational changes, and updated contact information are reflected in WHOIS as soon as the registry processes the update. Static databases imported on a schedule may miss recent changes.
WHOIS queries use TCP port 43 and return plain text responses. Modern alternatives like RDAP (Registration Data Access Protocol) provide structured JSON responses, but traditional WHOIS remains the most widely supported and queried protocol for internet resource lookups.
How We Use This Data
On robtex.com, rtsak.com, and dns.ninja, we perform live WHOIS queries to provide current ownership information for IP addresses and AS numbers. When you look up an IP address, we query the appropriate WHOIS server to retrieve the authoritative registration record.
Live queries are performed on demand when a user requests a lookup, ensuring the most current data is displayed. This is particularly important for:
- Recently transferred resources - IP blocks and ASNs that have changed hands appear with their new ownership immediately in live WHOIS, while pre-imported databases may still show the previous holder
- Updated contacts - Abuse contact changes are critical for security incident reporting and are reflected in real-time WHOIS
- Allocation status changes - Resources that change from allocated to assigned (or vice versa) are accurately reflected
We route queries through RADB when possible, as it provides a single query point that mirrors multiple registries. For resources where more detailed information is available from the authoritative RIR, we query the RIR directly.