What is CIDR used for?

CIDR, or Classless Inter-Domain Routing, is primarily used for allocating IP addresses in a more efficient manner compared to the traditional classful IP addressing system. It allows for the division of IP address space into more flexible and variable-sized address blocks rather than fixed sizes, which enhances the ability to assign blocks of addresses that closely match an organization’s actual needs at any given time.

By using CIDR notation, organizations can create subnets that optimize their IP address usage, reducing waste and improving network management. This method supports more hierarchical and efficient routing across the Internet and private networks, leading to better utilization of the available IP address space. Therefore, when asked about the purpose of CIDR, the focus on efficient IP address allocation accurately captures its primary function.