subnet_finder.py

#!/usr/bin/env python
# Example ./subnet_finder.py https://whois.arin.net/rest/org/DROPB/nets
from BeautifulSoup import BeautifulSoup
import requests
import sys

# Spoof your agent here
user_agent = "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.71 Safari/537.36"

# Set the user agent and accept headers, accept is required otherwise arin.net will return xml
headers = {
  'User-Agent': user_agent,
  'Accept': "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8"
}

# Grab the network page html, pull out the subnets and print them
def getSubnet(network_url):
  subnet_request = requests.get(network_url, headers=headers).text
  netblocks = BeautifulSoup(subnet_request).findAll('td')
  print netblocks[3].text

def main():
  
  # Grab url from arg 1
  url = sys.argv[1]

  # Make our actual request to get all links to the networks
  request = requests.get(url, headers=headers).text

  # Grab all the links on the page
  netblocks = BeautifulSoup(request).table.findAll('a')

  # Loop through all the network links on the main page
  for block in netblocks:
    subnet = block['href']
    getSubnet(subnet)

if __name__ == "__main__":
  if len(sys.argv) < 2:
    print "Usage: ./subnet_finder.py https://whois.arin.net/rest/org/DROPB/nets" 
    exit()
  else:
    main()