asn-db2 is a Rust library that can load and index ASN databases (ip2asn-v4.tsv, ip2asn-v6.tsv, ip2asn-combined.tsv files) from IPtoASN website.

This crate is a rewritten fork of Jakub Pastuszek's asn-db crate.

Once loaded it can be used to lookup an IP address for matching ASN record that contains:

• network base IP address and mask (e.g. ipnet::Ipv4Net value like 1.1.1.0/24),
• assigned AS number (e.g. 13335),
• owner country code (e.g. US),
• owner information (e.g. CLOUDFLARENET - Cloudflare, Inc.).

Both IPv4 and IPv6 addresses and networks are supported.

Example

Load database from ip2asn-v4.tsv file and lookup 1.1.1.1 IP address.

use asn_db2::Ipv4Database;
use std::fs::File;
use std::io::BufReader;

let db = Ipv4Database::from_reader(BufReader::new(File::open("ip2asn-v4.tsv").unwrap())).unwrap();
let entry = db.lookup("1.1.1.1".parse().unwrap()).unwrap();

println!("{:#?}", entry);

This prints:

Entry {
    subnet: 1.1.1.0/24,
    as_number: 13335,
    country: "US",
    owner: "CLOUDFLARENET",
}