IP Addressing & Subnetting
Medium
14 mins read
Prerequisites
- Binary to Decimal conversion
- Network Devices overview
Introduction
Computer Networks me internet traffic coordination ke liye IP addressing system scale define hoti hai. Har device (PC, Mobile) ko network location identify krne ke liye unique address code allocate hota hai.
Real-Life Analogy
💡 Home Mailing Address & Zip Code
Postal division mapping logic
| Concept Term | Real-life Analogy Mapping |
|---|---|
| Network ID | The Zip Code of your City/Region (determines group zone). |
| Host ID | Your specific house door number inside that zip code region. |
| Subnetting | Dividing a big office building into floors to make delivery easy. |
Detailed Concept Explanation
IP v4 represents a 32-bit address split into 4 octets separated by dots (e.g. 192.168.1.1). IP addresses standard classes include: - **Class A**: 0.0.0.0 to 127.255.255.255 (Default Mask: 255.0.0.0) - **Class B**: 128.0.0.0 to 191.255.255.255 (Default Mask: 255.255.0.0) - **Class C**: 192.0.0.0 to 223.255.255.255 (Default Mask: 255.255.255.0) - **Class D & E**: Multicasting and Research definitions.
Visual Diagram
Pointer Variable (ptr)Address: 0x7ffd100
0x7ffd98b
Value is another Address
Points to
Normal Variable (x)Address: 0x7ffd98b
45
Actual integer value
Important Point
- Private IP ranges include: 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16.
- First address in a network represents Network ID, Last address represents Directed Broadcast Address (DBA).
Mnemonic / Memory Trick
A-B-C-D-E (Ranges mapping limit)
Class A: 1-126 | Class B: 128-191 | Class C: 192-223 | Class D: 224-239
Mnemonic helper to index class limits easily.
Avoid This Common Mistake
Students calculate total hosts but forget to subtract 2 addresses: Network ID & Directed Broadcast Address. Network hosts count is always (2^H - 2).
GATE Exam Insights
Subnet mask allocations, CIDR boundary calculations, and supernetting constraints questions are highly repetitive in GATE Network examinations.
Practice Mini Quiz
Revision Summary (One-Page Notes)
- •IPv4 uses 32-bit addresses categorized into Classes A to E.
- •Mask splits Network and Host parts.
- •Subnetting enables local division of network hosts.