Guide
What Is an ASN?
An ASN, or Autonomous System Number, identifies a network that participates in internet routing.
Last reviewed: June 12, 2026
Quick reference
At a glance
- ASN
- A numeric identifier for an autonomous routing network.
- Organization
- The ISP, cloud provider, university, company, or network operator associated with that ASN data.
- Useful for
- Understanding provider context, routing ownership, VPN/proxy hints, and abuse triage.
- Not proof of
- A specific person, device, account, or exact physical location.
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Guide
What an ASN represents
Large ISPs, hosting providers, cloud networks, universities, and companies often operate autonomous systems.
ASN data can help explain whether an IP belongs to a residential ISP, a datacenter, a corporate network, a VPN, or another network type.
Guide
What ASN data does not prove
ASN data is network context, not identity. It does not prove who is using the address at a specific moment.
Cloud, proxy, mobile, and VPN networks can carry traffic for many unrelated users and organizations.
Reference
Key terms
- ASN
- Autonomous System Number
- BGP
- Border Gateway Protocol routing
- Organization
- The network operator associated with the ASN data
Examples
Examples
ASN format
AS12345
ASN values are commonly displayed with an AS prefix.
Lookup result
AS3292 TDC Holding A/S
Example of a network label returned by an IP lookup.
Look up an IP with ASN data
Next steps
Related guides and tools
Questions
FAQ
Does ASN identify a person?
No. ASN data identifies a routing network or organization, not a person or exact device.
Why does an IP lookup show a hosting provider?
The traffic may come from a server, VPN, proxy, or cloud service instead of a residential internet connection.
Sources