ASN Lookup
Enter any Autonomous System Number to get BGP routing data, announced prefixes, peer relationships, and RPKI validation - instantly.
BGP Routing
Announced prefixes, upstream & downstream peers, MOAS detection
RPKI Status
Route Origin Validation for all announced prefixes
Prefix Analysis
IPv4 and IPv6 prefix breakdown with address counts
Registry Data
RIR allocation, abuse contacts, organisation details
Popular ASN Lookups
What is an Autonomous System Number?
An Autonomous System Number (ASN) is a unique identifier assigned to a network operator by a Regional Internet Registry (ARIN, RIPE NCC, APNIC, LACNIC, or AFRINIC). Each AS controls a set of IP prefixes and uses BGP (Border Gateway Protocol) to exchange routing information with other autonomous systems. ASN lookups reveal which organization operates a network, what IP prefixes it announces, who its upstream and downstream peers are, and whether its routes are protected by RPKI (Resource Public Key Infrastructure). Enter any ASN above — for example, AS13335 (Cloudflare) or AS15169 (Google).