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ASN Lookup

Map a public IP to its announcing ASN and network organization

Use ASN Lookup when you already have an IP

This page is for live IP-to-ASN mapping. If you want to browse major network operators by type, open the ASN directory. If you are asking what ASN means, read the explainer first.

How lookup works

identify network operators. An ASN lookup maps an IP to its announced ASN and organization, typically based on CIDR ranges in routing tables.

When ASN lookup is most useful

ASN data is especially helpful for understanding who routes traffic for a given IP. It is not a precise ownership record, but it shows the network announcing the IP range in global routing tables. This is why ASN lookup is a common first step in abuse investigations, troubleshooting connectivity, or validating an ISP.

Results can vary based on how IP ranges are delegated. Large organizations may announce multiple CIDR blocks, while hosting providers may reassign ranges to customers. In those cases, pairing ASN data with WHOIS/ gives you both routing and registration context.

If you want to validate ownership details beyond ASN, use WHOIS/RDAP for registrant information and DNS tools to confirm hostnames and services.

  • Network troubleshooting: see which ASN announces the range and compare it with expected routing paths.
  • Security checks: identify if suspicious traffic is coming from a known provider or a residential ISP.
  • Infrastructure planning: confirm the ASN before setting up peering or firewall rules.

results in ISP, hosting, and VPN checks

ASN data is one of the fastest ways to understand what kind of network sits behind an IP. A residential ISP ASN usually suggests consumer connectivity, a hosting ASN often points to cloud or server infrastructure, and a known VPN or proxy provider ASN can explain why traffic appears to come from a different country or organization than expected. This does not prove intent, but it is extremely useful for sorting normal residential traffic from data center, enterprise, or privacy-network routes.

It is also a practical verification step when you connect a VPN. If your visible IP changes but the ASN still maps to the same ISP, the route may not have changed the way you expected, or the VPN app may be split tunneling traffic. When both the IP and ASN shift to a different network operator, that is a stronger signal that traffic is actually leaving through another provider. Pairing ASN lookup with proxy checks, DNS leak testing, and WebRTC testing gives you a much more trustworthy answer than IP change alone.

In enterprise and security workflows, ASN lookup also helps with allowlists, firewall rules, and abuse triage. You can quickly see whether repeated requests belong to one network family, whether a service is fronted by a major cloud provider, or whether a range has likely been delegated downstream. The safe interpretation is always contextual: ASN identifies the announcing network, while WHOIS, reverse DNS, and live behavior explain how that network is being used.

Quick reference: ASN types and what they tell you

Not all ASNs are equal. The type of ASN behind an IP changes how you should interpret the result:

  • Residential ISP(Comcast, AT&T, Deutsche Telekom): normal consumer traffic. The IP is likely assigned to a home or mobile user.
  • Hosting / cloud (AWS, DigitalOcean, Hetzner, OVH): the IP runs on server infrastructure. Often flagged as proxy/VPN by detection services.
  • VPN provider (NordVPN, Mullvad, Surfshark): the IP belongs to a privacy network. Expected when testing a VPN connection.
  • Enterprise / university (Google, Microsoft, MIT): the IP belongs to a large organization. May represent corporate VPN egress or campus traffic.
  • CDN / edge (Cloudflare, Akamai, Fastly): the IP is part of a content delivery network. Usually not end-user traffic.

Combine ASN type with , WHOIS data, and proxy signals for the most complete picture.

Frequently asked questions

What does this ASN lookup show?
It maps a public IP to the autonomous system currently announcing that route, along with the associated organization name when available.
What is an ASN?
ASN stands for Autonomous System Number. It identifies a network operator and is used by BGP to route traffic between networks.
Why does an IP lookup show ASN?
ASN indicates the network that announces the IP range. It helps identify the ISP or organization behind an IP.
Can one ASN contain many IP ranges?
Yes. Large networks announce multiple CIDR ranges under the same ASN.
Why can the ASN name differ from the ISP name?
A customer-facing ISP brand, hosting brand, or VPN brand may use infrastructure announced by a parent company, backbone, CDN, or transit provider. ASN data shows the routing organization, not always the marketing name users recognize.
Can ASN lookup identify VPN or proxy traffic?
It can provide useful clues, especially when an IP belongs to a hosting provider, VPN network, CDN, or mobile carrier, but ASN data alone should be combined with proxy checks, reverse DNS, WHOIS, and leak-test results.