In this tutorial, we will demonstrate you on how to convert IP address ranges into CIDR format.
What is CIDR #
CIDR, which stands for Classless Inter-Domain Routing, is a method used for efficiently allocating and routing IP addresses on the internet. It was introduced to overcome some limitations of the original IP addressing system, which relied on fixed-size address classes (Class A, B, and C) and led to inefficient use of address space. An example of CIDR notation, 8.8.8.0/24, which represents the IP ranges from 8.8.8.0 to 8.8.8.255.
CIDR allows for a more flexible allocation of IP addresses by using a prefix notation. In CIDR notation, an IP address is followed by a forward slash (“/”) and a number representing the length of the network prefix. The notation looks like this: IP_address/prefix_length. For example, 192.168.1.0/24 indicates a network with a 24-bit prefix, meaning the first 24 bits represent the network address, and the remaining 8 bits are available for host addresses.
Please take note that this tutorial only for the conversion of IPv4 to CIDR format. We will not display you a complete project, but the core function of how the conversion work.
This function, iprange2cidr, takes 2 input parameters, namely the ipStart and ipEnd, the starting and the ending of an IP address respectively. You can either supply the IP address in dotted format, for example, 202.186.13.4, or IP number, for example, 3401190660, as the input parameters. The function will convert them into IP number if the dotted IP address format was supplied and perform the calculation.
Below are the sample codes of the function written in several programming languages, such as PHP, VB.NET, C#, Java and Ruby.
The result that return by the iprange2cidr function is an Array that contains the list of CIDR formatted IP address. Looping has to be done to get all the CIDR formatted IP address from the return result. The following figure shows the sample output with ipStart:192.168.1.0 and ipEnd:192.168.1.9 of the converting IP address ranges into CIDR format.
192.168.1.0/29 192.168.1.8/31
The CIDR Calculator #
A CIDR calculator is a tool used in networking to facilitate the efficient management of IP addresses. It allows users to perform calculations related to Classless Inter-Domain Routing (CIDR), a method for allocating and routing IP addresses.
With a CIDR calculator, users can easily subnet IP address ranges, determine network and broadcast addresses, and aggregate multiple IP ranges into a single CIDR notation. These calculators are valuable for network administrators and engineers in planning and optimizing IP address allocations, enhancing routing efficiency, and ensuring the scalability of network designs. Additionally, CIDR calculators serve as educational tools for learning and practicing subnetting and IP address management concepts.
Get free IP address tool to translate IPv4 address range into CIDR or visit the IP2Location.io CLI tool for more usage examples. You can also use the IP2Location.io CLI tool to obtain IP address information.
