Read a file of network + CIDR masks, one per line; count the number of IP addresses it represents

countips.py

#!/usr/bin/env python
import sys

def countips(netblock):
    cidr = int(netblock.split('/')[1])
    return 2**(32 - cidr)

if (len(sys.argv) != 2):
    print(f"Usage: {sys.argv[0]} <file with CIDR masks>")
    sys.exit(0)

ipcount=0
with open(sys.argv[1]) as infile:
    for netblock in infile:
        ipcount += countips(netblock)
    print(ipcount)

do you have a version that also works with IPv6 addresses on the list?

This is what I came up with to account for IP lists that may or may not have the /32 and if the /is greater than 32 for IPv6 addresses

#!/usr/bin/env python3
import sys

def countips(netblock):
slash = netblock.find("/")
if slash != -1:
cidr = int(netblock.split('/')[1])
else:
cidr = 32
if cidr > 32:
return 2**(128 - cidr)
else:
return 2**(32 - cidr)

if (len(sys.argv) != 2):
print(f"Usage: {sys.argv[0]} ")
sys.exit(0)

ipcount=0
with open(sys.argv[1]) as infile:
for netblock in infile:
ipcount += countips(netblock)
print(f'{ipcount:,}')