Free tool
AS WHOIS & ASN Lookup
Autonomous System details: holder, registry, announced prefixes, upstreams and peers, IRR consistency and RPKI coverage.
About this tool
Look up any Autonomous System Number: holder, registry, announced IPv4/IPv6 prefixes, upstreams and downstreams, inferred relationships, IRR consistency and raw WHOIS/RDAP records.
Lookups are rate-limited and logged for abuse prevention. Results reflect public routing data and registries.