Awesome

ip2asn: Mapping IP address to originating ASN

Simple tool that matches IP addresses to ASN at any point in time.

Data structures are now compressed, if you used an older version of this repo you should clone it again (You should also use python3).

Example

Find the ASN for 8.8.8.8 (on Jan. 2017):

» python3 ip2asn.py 201701 8.8.8.8
15169

Yes, that's Google, but that wasn't like that in 2009:

» python3 ip2asn.py 200901 8.8.8.8
3356

Need more older/newer files?

Create data structures from RIB files (assume route-views file name but this can be easily changed) with this command: python3 readrib.py rib.20170401.0000.bz2

Need to map a lot of IPs?

Look at ip2asn.py. You don't need to load the datastructure each time you query an IP. Copy/paste the ip2asn.py code and call the ip2asn function as much as you like.