Search for **CIDR.xyz** in any browser

Click on the link with the domain address [cidr.xyz](https://cidr.xyz)

**What is CIDR?**\
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**CIDR (Classless Inter-Domain Routing)** is a method for allocating IP addresses more efficiently and for routing IP packets. Instead of using fixed classes (A, B, C), CIDR allows IP addresses to be assigned with flexible subnet masks, written as `IP address/Prefix length` (e.g., `192.168.1.0/24`). This prefix length indicates how many bits of the IP address are used for the network portion, enabling more precise allocation of IP address ranges.

Scroll to the blocks section and type **28** in the last block, here you can see that the COUNT and Decimal value has been changed based on the given CIDR value

You can also give different values and practice how the CIDR works

here you can see all the **NETMASK** and **IP's**

Congratulations! on completing this lab and Understanding CIDR Blocks

Google Cloud

This guide provides a comprehensive explanation of CIDR blocks, which are essential for efficient IP address allocation and network management.