BGP/ASN Lookup
Look up BGP autonomous system information for any IP or ASN.
Enter a public IP address (e.g., 8.8.8.8) or an ASN (e.g., AS15169) to look up BGP routing information.
What Is BGP and ASN?
The Border Gateway Protocol (BGP) is the routing protocol that holds the internet together. It determines how data packets travel between autonomous systems — the large networks operated by ISPs, cloud providers, enterprises, and content delivery networks. Each autonomous system is identified by a unique Autonomous System Number (ASN), assigned by regional internet registries like ARIN, RIPE NCC, and APNIC.
Understanding ASN Lookups
An ASN lookup reveals which organization operates the network that an IP address belongs to. When you query an IP, you get the ASN, the organization name, the network prefix (CIDR block), and the country of registration. When you query an ASN directly, you can see the prefixes announced by that autonomous system and their routing details.
Why This Matters
Network engineers use ASN data to troubleshoot routing issues, plan peering arrangements, and analyze traffic paths. Security analysts investigate ASN information during incident response to identify the owner of suspicious IP addresses. Hosting providers and CDN operators reference ASN data to optimize their network interconnections and understand traffic sources.
Common Use Cases
Determine which ISP or cloud provider hosts a particular IP address. Investigate network ownership during security incidents. Verify BGP prefix announcements for your own network. Research peering opportunities with other autonomous systems. Check if an IP belongs to a known hosting provider, VPN service, or content delivery network.