Validate the address
Only a literal, globally routable IPv4 or IPv6 address is sent to the evidence provider.
Direct answer: An IP-to-ASN lookup maps a public address to the autonomous-system and network context reported by the lookup source; it does not identify an individual user.
The server sends the public IP address to the named ASN evidence provider shown in the result. Result responses are private, uncached and excluded from search indexing. Do not enter passwords or secrets. Read the lookup privacy policy.
What this ip to asn lookup tells you
IP to ASN lookup maps a public IPv4 or IPv6 address to the network identity reported by the lookup source. It returns an ASN plus organization, ISP, network domain, connection type and country when available; it is not a live BGP route collector or a registry ownership determination.
- Which ASN the data source currently associates with the address
- The reported organization, ISP, network domain and connection type
- The source, observation time and limits needed to interpret the mapping
Use the IP WHOIS lookup when you need the RIR registration range, status, events and raw RDAP evidence behind an address.
How the evidence is collected
Read the provider mapping
The response can include an ASN, organization, ISP, network domain, connection type and country.
Scope the conclusion
Hosting, transit, anycast and customer assignments can involve several organizations with different roles.
Read the fields without overclaiming
| Signal | What it can establish | What it does not prove |
|---|---|---|
| ASN | The autonomous-system number associated with the address by this source. | A company identity or proof of the current route from every vantage point. |
| Organization / ISP | Provider labels attached to the address mapping. | The publisher of a website or the individual using the address. |
| Network domain | A domain label the provider associates with the network. | The reverse DNS hostname or every domain hosted on the address. |
| Country | A country reported by the IP evidence provider. | A precise device location or registry ownership statement. |
A CDN anycast address maps to one ASN
The same address can be served from many sites while BGP directs users to nearby nodes. The ASN is useful for routing and abuse triage, but it does not reveal the origin application server or the visitor's exact serving location without additional measurements.
Common mistakes
- Treating registry data as a live BGP table
- Calling an ASN a hosting company without checking its role
- Inferring location from a globally routed prefix
- Ignoring more-specific routes and anycast
IP to ASN Lookup FAQ
What is an autonomous system?
It is a set of IP routing prefixes operated under a coherent routing policy and identified in BGP by an AS number.
Can an IP have more than one origin ASN?
Route observations can show multi-origin announcements, whether intentional or problematic. A single lookup may not expose every vantage point.
Is the ASN the website owner?
Usually not. It may belong to a carrier, CDN, cloud or hosting network used by the publisher.