• RIRs maintain databases mapping IPs and ASNs, queryable via whois. • Team Cymru offers DNS-based IP-to-ASN lookup, requiring reversed octets for queries. • IPv4 query example: dig +short TXT 31.108.90.216.origin.asn.cymru.com returns ASN data. • IPv6 query requires complex reversal, e.g., 2001:4860::/32 example to retrieve ASN info. • Preprocessing steps seen as unnecessary; direct query would simplify usage. • Classic DNS uses zone files; alternative database approach could improve flexibility.
Article Summaries:
- A new DNS‑based IP‑to‑ASN lookup service has been demonstrated that removes the need for the cumbersome preprocessing required by Team Cymru’s existing tool. While Team Cymru’s DNS variant demands that IPv4 octets be reversed and IPv6 delimiters replaced before querying, the new approach uses PowerDNS’s plug‑in backend to perform database lookups directly. This eliminates the reverse‑ordering step and allows straightforward queries such as
dig +short TXT 216.88.0.0.or. The demonstration also highlights DNS’s flexibility with label characters and the viability of database‑backed authoritative zones, offering a simpler, more user‑friendly method for retrieving ASN information.
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