RFC 1918 (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16)

NETWORKING

When we use the internet and want to communicate with other computer,mobile or using any service over the internet.To access services we need a online identity, without online identity we can't access any internet related services. IP is the our online identity for connect with all internet services and works. IP like a our postal address.

In a technical language: An IP (Internet Protocol) address is a unique numerical label assigned to each device connected to a computer network that uses the Internet Protocol for communication.

Key Points

• It acts like a digital address for devices on a network.

• It enables communication between computers, servers, and other devices.

if we want to know about our public ip address so we will check our ip address into this website name https://whatismyipaddress.com/

There are 2 Types of IP Available

1. Public IP
2. Private IP

Public IP :

A public IP address is the unique identifier assigned to your entire network by your Internet Service Provider (ISP). It is visible on the internet and allows external devices, websites, and services to communicate with your network.

Key Characteristics

• Assigned by ISP: Your router receives a public IP from your internet provider.

• Same for all devices in the network: All devices connected to your router share this public IP when accessing the internet.

• Globally unique: No two networks on the internet can have the same public IP at the same time.

• Required for communication: Websites, servers, and online services use public IPs to send data back to your network.

Private IP

A private IP address is an IP address used only inside a local network (home, office, data center, cloud). It is not routable on the public Internet, meaning Internet routers block it. To access the Internet, devices with private IPs must use NAT (Network Address Translation).

Key Characteristics

1. Used Only Inside Local Networks

Private IPs work within:

• Home Wi‑Fi
• Office LAN
• Data centers
• Cloud VPC/VNet

2.Not Routable on the Public Internet

• Internet routers drop private IP packets.

• They cannot directly access the Internet.

Important Note :- The users of internet incresing day by day but public ips limited or its not free. every organisation or data center need huge numbers of ip for conneting there device or service for communication and data sharing purpose. Due to public ip limited and its very precious so its not easy for the user buy huge numbers of ips so for this problem solution RFC 1918 made it easy and allow users to use Huge number of Private ip for organisation internal communication and data sharing.

RFC 1918

RFC 1918 is a standard published by the Internet Engineering Task Force (IETF) that defines private IPv4 address ranges used inside local networks — such as homes, offices, data centers, and cloud environments. These IPs are not routable on the public Internet and require NAT to go outside.

Why RFC 1918 Exists

IPv4 addresses are limited

Millions of networks need internal IPs

Private IPs can be reused everywhere

Keeps internal devices hidden from the Internet

Why RFC 1918 Exists IPv4 addresses are limited

Millions of networks need internal IPs

Private IPs can be reused everywhere

The 3 Private IP Ranges (Defined by RFC 1918)