(c) Arnim Eijkhoudt , 2017, KPN-CERT, GPLv2 license

Netchecker lets you offline-check a list of IP addresses against known AS numbers/names. Works with both IPv4 and IPv6! This tool is useful for checking of e.g. leaked/dumped IPs against ASNs to see if there are matches, without having to use internet sources and thereby risking the possibility of announcing your interest in the checked IPs.

1. Python 2.7.x / 3.x (should work with both...)
2. netaddr module (installable through PyPi etc.): https://pypi.python.org/pypi/netaddr
3. MaxMind's GeoLite ASN databases: http:https://dev.maxmind.com/geoip/legacy/geolite/

1. git clone https://github.com/uforia/netchecker.git
2. pip install netaddr / apt-get install python-netaddr / emerge dev-python/netaddr / or whatever you use for package management
3. download the GeoLite ASN databases: http:https://dev.maxmind.com/geoip/legacy/geolite/ and unpack them in the netchecker directory

1. Create a list of IPs in plaintext, one IP per line, in a single file, e.g.: 'ips.txt'
2. Open netchecker.py in an editor and change the 'MyASN' variable's contents at the top to reflect your AS names/numbers
3. Run netchecker: ./netchecker.py ips.txt

• The more AS names/numbers you check, the longer it takes to build the list of netblocks to verify against!
• This product includes GeoLite data created by MaxMind, available from http:https://www.maxmind.com
• Configuration option parsing at the CLI to specify the MyASNs
• An automatic GeoIPLite downloader might be included in the future