TheDNSMuseum
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Tools and toys

IP to ASN

Team Cymru maps an IP address to its autonomous system number through a structured DNS query, giving network operators a scriptable routing lookup.

ASNTeam Cymrunetwork operations

Date updated:

Screenshot used in the talk for IP to ASN
Screenshot used in the original talk.

Team Cymru’s DNS service maps an IP address to autonomous-system information. The query name represents the address, and the response provides routing data.

For network operators, this is faster to script than a conventional WHOIS lookup. It is one of the strongest practical examples in the collection.

Primary source: https://team-cymru.com/community-services/ip-asn-mapping/#dns