cidrtool

cidrtool is a simple command line tool to manipulate CIDR blocks.

Usage

Expand netblock

cidrtool --expand reads a list of CIDR blocks from stdin and expands them to a list of IP addresses.

echo "192.168.0.0/16" | cidrtool --expand

Collapse netblocks

cidrtool --collapse4 or --collapse6 reads a list of IP v4 or v6 addresses from stdin and collapses them to a list of CIDR blocks.

echo "192.0.2.0/25
192.0.2.128/25" | cidrtool --collapse4

Requirements

cidrtool requires Python 3. In particular, /usr/bin/env python3 must be a usable Python 3 interpreter.

Installation

Debian/derivatives via apt repository

Install my Debian repository, if you haven't already:

sudo apt-get install ca-certificates curl gnupg
sudo install -m 0755 -d /etc/apt/keyrings
curl -fsSL https://dist.cdzombak.net/deb.key | sudo gpg --dearmor -o /etc/apt/keyrings/dist-cdzombak-net.gpg
sudo chmod 0644 /etc/apt/keyrings/dist-cdzombak-net.gpg
echo -e "deb [signed-by=/etc/apt/keyrings/dist-cdzombak-net.gpg] https://dist.cdzombak.net/deb/oss any oss\n" | sudo tee -a /etc/apt/sources.list.d/dist-cdzombak-net.list > /dev/null
sudo apt-get update

Then install cidrtool via apt-get:

sudo apt-get install cidrtool

macOS via Homebrew

brew install cdzombak/oss/cidrtool

License

cidrtool is licensed under the LGPL-3.0 License. See the LICENSE file for details.

Author

Chris Dzombak