ASN Lookup

Look up an autonomous system by number or IP: who holds it, every IPv4 and IPv6 prefix it announces, and its main upstream providers.

Every network on the internet routes its addresses as an autonomous system (AS): your ISP, a cloud provider, a company with its own address space. Enter an AS number, or an IP address to find the AS that routes it, and see who holds it, every address block it announces right now, and the upstream networks it buys transit from. Routing data comes from RIPE NCC's RIPEstat, which covers all five regional registries.