cidr

cidr is a command-line tool for managing IPv4 and IPv6 CIDR network prefixes. It provides essential network administration functions through a simple interface, supporting both address families with identical command syntax.

The tool offers several core operations: explaining CIDR ranges with detailed network information including base address, usable range, broadcast address, and netmask; checking if specific IP addresses belong to a given CIDR range; counting total addresses within a network prefix; detecting overlaps between different CIDR ranges; and dividing networks into smaller subnets.

Network administrators, DevOps engineers, and system administrators working with IP address planning and network segmentation would find this tool useful. The consistent command structure works across both IPv4 and IPv6, making it suitable for dual-stack network environments. Commands like cidr explain 10.0.0.0/16 provide comprehensive network details, while cidr divide 10.0.0.0/16 9 splits networks into smaller subnets for subnet planning.

Installation

# via Homebrew
brew install cidr

# via APT
apt install cidr