ASN Lookup
Look up an autonomous system by ASN (e.g. AS15169).
About the ASN Lookup Tool
The ASN Lookup tool takes an Autonomous System Number (like AS15169 for Google or AS16509 for AWS) or an IP address and returns full ASN details — network operator name, country, allocation date, announced IP prefixes, and peering relationships. ASNs are the fundamental unit of routing on the internet — every IP belongs to exactly one ASN at any given time, and knowing the ASN tells you who really owns the network.
Network engineers use ASN lookups to plan BGP peering, verify route announcements, and investigate routing anomalies. Security teams use them for threat intelligence — identifying which cloud provider or ISP a suspicious IP belongs to. Cloud architects use them to plan multi-cloud strategies and confirm that traffic is following the expected paths.
ASN data is drawn from the Regional Internet Registries (ARIN for North America, RIPE for Europe, APNIC for Asia-Pacific, LACNIC for Latin America, AFRINIC for Africa) which maintain the authoritative allocations. Because BGP route data is public, this is one of the more transparent parts of internet infrastructure.
How to use this tool
- 1Enter the required value in the input field above (domain, IP, URL, or text depending on the tool).
- 2Click the action button to run the check — results are computed instantly from our edge network.
- 3Review the parsed output, key fields and any warnings shown in the result card.
- 4Copy the result, share the page URL, or jump to a related tool from the sidebar to continue debugging.
Key features
- Full ASN details including RIR and allocation date
- Announced IP prefix list
- IP-to-ASN reverse lookup
- Fast, edge-hosted queries