IP2ASN takes a list of domains and resolves their ASN information using Team Cymru's IP to ASN Mapping Service

This implementation uses the WHOIS interface which is not mean for large numbers of individual queries.

This application take a newline separated list of domains

From a file

./ip2asn input.txt

From STDIN

cat input.txt | ./ip2asn

To CSV

./ip2asn -o output.csv input.txt

In order to build, you must have a properly installed and configured installation of Go 1.4 or greater

git clone https://github.firehost.co/chinkley/ip2asn.git
cd ip2asn
go get "github.com/codegangsta/cli"
go build && go install

IPs that are seen abusing the whois server with large numbers of individual queries instead of using the bulk netcat interface will be null routed. If at all possible you should consider using the DNS based query interface since it is much more efficient for individual queries. The netcat interface should be used for large groups of IP lists at a time in one single TCP query.