asn

ASN is a command-line network reconnaissance tool that performs comprehensive analysis of IP addresses, autonomous systems, and network infrastructure. It combines multiple data sources to provide detailed information about ASN ownership, BGP statistics, peering relationships, RPKI validity, and IP geolocation. The tool can trace network paths using mtr, identify Internet Exchange Points (IXPs) along routes, and validate routing announcements against published RPKI ROAs to detect potential BGP hijacks or route leaks.

The tool integrates with over 20 data sources including Team Cymru, PeeringDB, CAIDA ASRank, Shodan, and various threat intelligence feeds to provide IP reputation scoring and threat analysis. It can perform bulk geolocation operations, identify IP types (anycast, mobile, datacenter), and map IPv4/IPv6 address space allocated to specific countries. For security analysis, it reports known vulnerabilities, open ports, and services using Shodan's InternetDB API.

ASN supports multiple operational modes including interactive command-line usage, web-based traceroute server, and JSON API endpoint for integration with other tools. The server mode allows launching lookups from browsers via bookmarklets or from terminals using curl. Network administrators, security researchers, and incident response teams can use it for investigating network anomalies, performing reconnaissance on target networks, and analyzing BGP routing behavior.