BGP AS Lookup

Use the IP to AS Lookup mode in this tool by entering any valid IPv4 or IPv6 address. The tool will query BGP routing tables to identify the AS that announces the route for that IP, along with the specific prefix (CIDR block) it belongs to. This is useful for identifying the network operator responsible for an IP address or investigating network connectivity.

Regional Internet Registries are organizations that manage the allocation and registration of IP addresses and AS numbers within specific geographic regions. There are five RIRs: ARIN (North America), RIPE NCC (Europe, Middle East, Central Asia), APNIC (Asia Pacific), LACNIC (Latin America and Caribbean), and AFRINIC (Africa). This tool displays which RIR allocated each AS number.

Prefixes are blocks of IP addresses that an AS advertises via BGP to the internet. IPv4 prefixes use the format like 8.8.8.0/24 (announcing 256 addresses), while IPv6 prefixes are longer, like 2001:4860::/32. This tool shows how many IPv4 and IPv6 prefixes each AS announces, giving insight into the size and scope of a network operator.

The tool displays abuse contact email addresses when available for each AS. These contacts are registered with the RIR and should be used to report network abuse, spam, security incidents, or other issues originating from that network. Copy the abuse contact email directly from the results to submit your report.

Yes, you can export AS information in either JSON or CSV format. The export includes the AS number, name, description, country, RIR allocation, prefix counts, and contact information. This is useful for documentation, network analysis reports, or integrating the data into other tools and databases.