IP ranges, ASNs, and who owns an address
2026-05-16
Every public IP belongs to a block, and every block is announced by an autonomous system — an ASN — that identifies the network operating it. The mapping is public. From a single address you can usually name the cloud, carrier, or company behind it.
For bot analysis the ASN is context, not verdict. A crawler claiming to be from a search engine but arriving from a residential broadband ASN is almost certainly a costume; the same claim from the operator's own ASN is merely consistent with the truth.
Consistency is not proof, which is why range verification beats ASN heuristics: an operator publishing 'these exact addresses are ours' makes a checkable statement. The ASN tells you the neighborhood; the published range names the house.