**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.