I just open sourced a tool I wrote a little while back called NetList.

NetList is a small networking and security auditing script I wrote in Ruby. Given a search term, it will query the ARIN database for an organization and all of its related networks. This can assist a pen tester in finding out which networks are owned by the target, and noting them for a later scan and audit.

Check out the GitHub repo to download it. And please, use this responsibly and ethically. The ability to map who owns what IP ranges on the Internet is pretty powerful.

Example Output

$ ruby netlist.rb facebook
[!] Starting NetList script...
[!] Found 3 organizations matching your query, "facebook".
[!] Starting network lookup queries...

----- FACEBOOK (FACEB) -----

* UU-65-201-208-24-D7
  65.201.208.24 - 65.201.208.31

----- Facebook Inc (FACEB-1) -----

* FACEBOOK-CORP
  2620:10D:C000:: - 2620:10D:C0FF:FFFF:FFFF:FFFF:FFFF:FFFF

----- Facebook, Inc. (THEFA-3) -----

* TFBNET3
  66.220.144.0 - 66.220.159.255

* TFBNET4
  74.119.76.0 - 74.119.79.255

* TFBNET1
  204.15.20.0 - 204.15.23.255

* TFBNET2
  69.63.176.0 - 69.63.191.255

* FACEBOOK-IPV6-BLOCK-1
  2620:0:1C00:: - 2620:0:1CFF:FFFF:FFFF:FFFF:FFFF:FFFF

* FACEBOOK-INC
  173.252.64.0 - 173.252.127.255

[!] Done. Enjoy!

$ ruby netlist.rb nasdaq
[!] Starting NetList script...
[!] Found 3 organizations matching your query, "nasdaq".
[!] Starting network lookup queries...

----- NASDAQ (NASDA-4) -----

* NASDAQ313-245-32
  12.148.245.32 - 12.148.245.63

----- NASDAQ Stock Market (NSM-28) -----

* SAVV-S259211-0
  216.90.143.224 - 216.90.143.231

----- Nasdaq Stock Market, Inc., The (NSMI-3) -----

* SAVV-N05736-0
  209.144.94.88 - 209.144.94.95

[!] Done. Enjoy!