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IPv4 Address Classes!

An IP Address is like the identity card of every device on a network . In IPv4, addresses are divided into 5 classes:

🔹 Class A: 0.0.0.0 – 127.255.255.255
🔹 Class B: 128.0.0.0 – 191.255.255.255
🔹 Class C: 192.0.0.0 – 223.255.255.255
🔹 Class D: 224.0.0.0 – 239.255.255.255 (Multicasting)
🔹 Class E: 240.0.0.0 – 255.255.255.255 (Research & Experimental)

Special Reservations:

■ 0.0.0.0 → Default routing
■ 127.0.0.0 → Loopback testing
■ Class D → Multicasting
■ Class E → Research

Private IP Ranges (used in LAN):

■ Class A: 10.0.0.0 – 10.255.255.255
■ Class B: 172.16.0.0 – 172.31.255.255
■ Class C: 192.168.0.0 – 192.168.255.255

Public IP Ranges (used on the Internet):

Class A, B, C (excluding private ranges)

In simple terms:

Private IP = Used inside your home/office network.
Public IP = Used on the internet.