subnet-divider.py

#!/usr/bin/env python3
"""Show subnets information.

Given an IP network in CIDR notation and the minimum number of desired subnets,
this script will provide the relevant information about the desired subnets.

Example:
    $ ./subnet-divider.py 10.10.0.34/16 4
    $ ./subnet-divider.py fd3e:48fe:59b2:43ca::/64 15

Adapted from:
    https://github.com/eyablokov/subnet-divider
"""

import math
import sys
import ipaddress


def divide_network(network, parts):
    """ Generator to return the resulting subnets after dividing a main network """

    if parts <= 1:
        subnet_diff = 0

    elif (parts & (parts - 1)) == 0:
        subnet_diff = int(math.log2(parts))

    else:
        subnet_diff = int(math.log2(parts)) + 1

    if (subnet_diff+network.prefixlen) > network.max_prefixlen:
        print('Unable to divide the given network into that many subnets')
        sys.exit(1)

    for subnet in network.subnets(prefixlen_diff=subnet_diff):
        yield subnet


# Get the main network, to divide onto predefined parts
net = ipaddress.ip_network(sys.argv[1], strict=False)

# Get the require number of subnets to which the network will be divided
parts = int(sys.argv[2])

for subnet in divide_network(net, parts):
    print("")
    print(f"CIDR:       {subnet}")
    print(f"Netmask:    {subnet.netmask}")
    print(f"Network:    {subnet.network_address}")
    if subnet.num_addresses == 1:
        print(f"Host Count: 1")
    else:
        print(f"Gateway:    {subnet.network_address+1}")
        print(f"Broadcast:  {subnet.broadcast_address}")
        print(f"Host Count: {subnet.num_addresses-1}")

This is deprecated, since it was migrated to the published subnet-utils package: https://github.com/fictivekin/subnet-utils/