ASN Lookup
Enter an AS number, an IP address, a prefix or a domain. We show which network announces it, the address space that network routes, and the networks it connects to, from public BGP data.
What this shows
- OwnerWho runs itThe AS holder, country, regional registry and allocation date.
- RouteWhere an IP sitsThe announced prefix, its origin AS, reverse DNS and RPKI status.
- PrefixesAddress spaceEvery IPv4 and IPv6 prefix it announces, by size.
- PeersConnectionsUpstream and downstream networks seen in BGP paths.
An AS number identifies one network’s routing policy on the internet. BGP data shows how networks connect, not the business agreements behind each link, so “upstream” means the neighbour sits closer to the route collectors in observed paths. Read Autonomous systems and ASNs explained for the basics, or the technical details for sources and limits.