SubnetHostCount

Simple python to count hosts in a list of subnets and ip addresses

CIDR Host Counter

This script reads a file containing IPv4 CIDR notations or individual IP addresses and calculates the total number of valid hosts. It excludes network and broadcast addresses for subnets, but counts single IPs (e.g., 10.0.0.5) as one valid host.

Features

• Accepts a file containing:
  • IPv4 CIDR ranges (e.g., 192.168.1.0/24)
  • Individual IP addresses (e.g., 10.0.0.5)
• Excludes network and broadcast addresses from the host count
• Ignores empty lines and lines starting with #
• Warns about invalid lines with a descriptive message
• Identifies duplicates (-D to list hosts appearing in multiple files)
• Calculates RFC1918 private vs public host counts (-r)

Usage

Prerequisites

Python 3.6+

Command

python HostCount.py -d path/to/cidrs.txt

or

subnethostcount -d path/to/cidrs.txt

Optional flags:

• -D, --duplicates
  When processing a directory, list hosts that appear in more than one file and which files they appear in.

• -r, --rfc1918
  Show how many hosts are in RFC1918 private address space vs how many are not (prints per-file and totals).