IP Addressing

Описание: IP Addressing Explained – IPv4, IPv6, Subnet Mask, Public vs Private IP
What is an IP Address?

An IP Address (Internet Protocol Address) is a unique number assigned to each device on a network so it can be identified and communicate with other devices.

Real-Life Example

Think of an IP address like a home address:

A package (data) needs a destination

Without an address, it can’t be delivered

IPv4
IPv4 (Internet Protocol version 4)

32-bit address

Written as four numbers separated by dots:

192.168.1.10


Each number ranges from 0 to 255

Total possible addresses: 4.3 billion

Problem

Too many devices → not enough IPv4 addresses (smartphones, laptops, IoT, cars)!

IPv6
IPv6 (Internet Protocol version 6)

128-bit address

Written in 8 groups of hexadecimal numbers:

2001:0db8:85a3:0000:0000:8a2e:0370:7334


Total addresses: 340 undecillion (huge number)
Enough addresses for every grain of sand on Earth—and more!

Why IPv6 is needed
Reason Explanation
Address shortage IoT explosion requires more addresses
Faster routing Simplifies processing
Built-in security IPSec support
Auto-configuration Plug-and-play network setup
Subnet Mask

Subnet masks divide one large network into smaller sub-networks (subnets).

Example
IP: 192.168.1.10
Subnet Mask: 255.255.255.0


First 3 numbers = Network part

Last number = Host part

So the subnet represents:

192.168.1.0 – 192.168.1.255


Devices in the same subnet can communicate directly.

Purpose

Better security

Better performance

Efficient use of addresses

Public vs Private IP
Type Use Example Ranges
Public IP Identifies your network on the Internet Assigned by ISP
Private IP Used inside home or business networks Not accessible directly from the Internet
Private IP Ranges
Range Example Use
10.0.0.0 – 10.255.255.255 Large organizations
172.16.0.0 – 172.31.255.255 Medium networks
192.168.0.0 – 192.168.255.255 Home Wi-Fi networks
Example
Your phone → 192.168.1.12 (private IP)
Router → 115.89.22.10 (public IP)

NAT (Network Address Translation)

Since private IPs cannot directly access the Internet, the router uses NAT to convert private IP → public IP.

Quick Overview Chart
Feature IPv4 IPv6
Size 32-bit 128-bit
Format Decimal Hexadecimal
Example 192.168.1.5 2001:db8::1
Total addresses 4.3 billion 340 undecillion
Header Simple Complex
Security Add-on Built-in
In Simple Words

IP addresses identify devices on a network. IPv4 is older and limited. IPv6 provides more space and better efficiency. Subnet masks divide networks, and public vs private IPs control access.