(c) Arnim Eijkhoudt <arnime squiggly kpn-cert.nl>, 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. [required] netaddr module (installable through PyPi etc.): https://pypi.python.org/pypi/netaddr
3. [required] For Python 2.7: ipaddress module: https://pypi.python.org/pypi/py2-ipaddress
4. [optional] 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 else you use for package management
3. download the GeoLite ASN databases by running ./netchecker.py -u

1. Create a list of IPs in plaintext, one IP per line, in a single file, e.g.: 'ips.txt'
2. Run netchecker: ./netchecker.py and check the command line options

• The more AS names/numbers you check, the longer it takes to build the list of netblocks to verify against!
• This product uses GeoLite data created by MaxMind, available from http:https://www.maxmind.com
• TO-DO: build a lookup table/cache after running the -u (update) command, to speed up lookups