ASN and BGP Prefix Lookup by IP


Enter an IPv4 or IPv6 address to see its origin ASN, advertised BGP prefix and autonomous system name.

IPv4 / IPv6 address
Reference data from public BGP routing sources. Query results are not stored.

How to read the result


Compare the origin ASN and prefix with information from your provider or autonomous system. An unexpected ASN is a reason to investigate, but it does not by itself prove a route leak or hijack.

Before making a network decision, also check RPKI, IRR records and your upstream operator. Public routing sources may update with a delay.

What is an origin ASN?

It is the autonomous system number that announces the BGP prefix containing the queried IP.

Is IPv6 supported?

Yes. The tool accepts both IPv4 and IPv6 addresses.