IP Address Classes Explained for Beginners

Did You Know? IP Addresses Have Classes!
Ever wondered how devices find each other on the internet? It all starts with an IP address - a unique identifier for every device online!

Before the modern IP allocation methods, IPv4 addresses were split into different classes to manage networks of all sizes.

Class A: Huge Networks​

• Range: 0.0.0.0 - 127.255.255.255
• Use: Big corporations, massive networks

Class A addresses were designed for networks that need millions of devices. Only the first 8 bits define the network, leaving plenty of space for hosts.
Example: 10.0.0.1 → A corporate main server

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Class B: Medium-Sized Networks​

• Range: 128.0.0.0 - 191.255.255.255
• Use: Universities, medium organizations

Class B is perfect for networks requiring thousands of hosts, with the first 16 bits defining the network and the rest for hosts.
Example: 172.16.5.10 → University lab computer

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Class C: Small Networks​

• Range: 192.0.0.0 - 223.255.255.255
• Use: Small businesses, home Wi-Fi

Class C is ideal when you only need a few hundred devices. Most home networks use Class C addresses.
Example: 192.168.1.1 → Home router IP

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Class D: Multicast​

• Range: 224.0.0.0 - 239.255.255.255
• Use: One-to-many communication, multicast streams

Class D addresses aren’t for standard network hosts. They’re used when one sender wants to broadcast data to multiple receivers.
Example: 224.0.0.1 → Streaming updates to multiple devices

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Class E: Experimental & Reserved​

• Range: 240.0.0.0 - 255.255.255.255
• Use: Reserved for research, future tech

These addresses are mostly for testing or future experiments and are not used in public networks.

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Fun Fact: CIDR Replaced Classes​

Today, CIDR (Classless Inter-Domain Routing) makes IP allocation smarter and more efficient, letting networks scale easily without wasting addresses.