🦸‍♂️ Subnethero

Subnethero is a powerful C-based command-line tool designed to help network administrators and IT professionals generate subnetting tables and manage IP ranges for different network configurations. Whether you're using a flat approach, FLSM (Fixed-Length Subnet Mask), or VLSM (Variable-Length Subnet Mask), this tool will streamline the process of subnetting and ensure you get precise network breakdowns.

🧮 Features

• Multiple subnetting approaches (flat, flsm, vlsm)
• Simple command-line interface
• Displays subnet information in a clear tabular format
• Generates subnetting tables with efficient algorithm
• Save the output to a csv file
• Parse csv to get network configuration
• IP lookup to know which subnet owns an IP

📡 Installation

1. Download subnethero with git

git clone https://github.com/giovanni-iannaccone/subnethero
cd subnethero

2. Compile it using make

make all

💡 Command-Line Usage

subnethero v1.0

Usage:
subnethero [-t | -f | -v] -c cidr -i ip -s n {n devices for each network}

Options:
  -t | --flat        use the flat approach
  -f | --flsm        use the flsm approach
  -v | --vlsm        use the vlsm approach

  -i | --ip          specify the IP of the base network
  -c | --cidr        the CIDR of the original network
  -s | --subs        number of subnetworks (followed by n devices for each network)

  Optional:
  -p | --input       read network configuration from a csv file
  -o | --output      copy the output into csv file
  -l | --lookup      find which subnet owns an ip

Example: subnethero -v -c 24 -i 192.168.1.0 -s 3 64 5 15

Parameters:

• -t | --flat
  This option uses a flat approach to subnetting, dividing the network into one big subnet.

• -f | --flsm
  This option applies the Fixed-Length Subnet Mask method, creating subnets of the same size based on the given number of devices.

• -v | --vlsm
  This option uses the Variable-Length Subnet Mask method, where each subnet can vary in size according to the number of devices specified.

• -i | --ip
  Enter the starting IP address of the network you want to subnet (e.g., 192.168.1.0).

• -c | --cidr
  Specify the CIDR notation for the original network (e.g., /24).

• -s | --subs
  Define the number of subnets you need, followed by the number of devices in each subnet. The tool will calculate the necessary subnet masks.

• -p | --input
  Read network configuration from a csv file and do calculations on that configuration (e.g., lookup).

• -o | --output
  Copy the output to a csv file (e.g., output.csv), don't specify anything to print the table to stdout.

• -l | --lookup
  To determine which subnet a specific IP address belongs to, simply add the -l IP flag at the end of your command.

🛸 Output Format

For each subnet, the output will generate the following columns:

IP	CIDR	Broadcast	Start	End	Free from	to
192.168.1.0	/26	192.168.1.63	192.168.1.1	192.168.1.32	192.168.1.33	192.168.1.62
192.168.1.64	/26	192.168.1.127	192.168.1.65	192.168.1.69	192.168.1.70	192.168.1.126
192.168.1.128	/26	192.168.1.191	192.168.1.129	192.168.1.143	192.168.1.144	192.168.1.190

🧩 Contributing

We welcome contributing. See CONTRIBUTING.md file for details

⚖️ License

This project is licensed under the GPL-3.0 License. See the LICENSE file for details.

⚔️ Contact

• For any inquiries or support, please contact iannacconegiovanni444@gmail.com .
• Visit my site for more informations about me and my work https://giovanni-iannaccone.github.io