IP Address
An IP Address (Internet Protocol Address) is a unique number given to every device in a network so they can identify and communicate with each other.
- When a device connects to the internet, the router or Internet Service Provider (ISP) assigns it a unique identifier called an IP address.
- This IP address enables the device to communicate over the internet.
- It is used to send requests to web servers.
- The server uses the same IP address to return the response to the correct device.
Key Points
- An IP address is a unique identifier assigned to every device connected to a network.
- It allows devices to communicate with each other over the internet or a local network.
- IP addresses are assigned by a router (for local networks) or an ISP (for internet access).
- IP addresses come in two versions: IPv4 (32-bit) and IPv6 (128-bit).
- IPv4 uses a dot-decimal format (e.g., 192.168.1.10), while IPv6 uses hexadecimal format.
- IP addresses can be public (internet-facing) or private (used inside networks).
- They can be dynamic (changes automatically) or static (permanently assigned).
- An IP address consists of a network part and a host part, defining network and device identity.
- It is essential for sending requests to servers and receiving responses back to the correct device.
- IP addresses work closely with subnet masks, routers, DNS, and NAT to ensure proper network communication.
- IP addresses can change when the network changes – for example, when you:
- switch from Wi-Fi to mobile data
- connect to a different Wi-Fi
- restart the router (in case of dynamic IP)
NAT (Network Address Translation)
NAT is a process used in routers to translate Private IP addresses into a Public IP address when accessing the internet. It allows many devices inside a home/office to share one public IP.
Example:
Your phone IP: 192.168.1.5, Router converts to: 49.37.92.201 (public IP). Router uses a single public IP for all your devices.
You and your brother use the same WiFi. You browse YouTube, He plays PUBG. Server sees both requests coming from the same public IP.This is possible because of NAT.
DHCP = Dynamic Host Configuration Protocol
DHCP is a network protocol that automatically assigns IP addresses and network settings to devices when they connect to a network.
Why We Use an IP Address?
- Identify devices on a network: An IP address works like a digital address that uniquely identifies each device connected to the internet or a local network.
- Send data to the correct destination: When you request a webpage, your IP address tells the server where to send the response.
- Enable communication between devices: Computers, servers, phones, routers—all communicate using IP addresses.
- Route data across the internet: Routers use IP addresses to decide the path your data packets should follow.
- Differentiate between networks and devices: The IP address contains a network part and a host part, helping to locate both the network and the specific device.
- Access online services: Every online activity—opening websites, streaming, gaming, emailing—requires an IP to function.
- Maintain security and tracking: IPs help in logging user activity, restricting access, and ensuring secure communication.
Versions of IP Address
There are two main versions of IP addresses used in networking:
IPv4 (Internet Protocol Version 4)
IPv4 is the fourth version of the Internet Protocol and the most widely used system for identifying devices on networks and the internet.
- Most widely used version today
- 32-bit address
- Written in dot-decimal format: Example: 192.168.1.10
- Total possible addresses: 4.3 billion
- Limited address space (one main reason IPv6 was created)
IPv6 (Internet Protocol Version 6)
IPv6 is the newest version of the Internet Protocol, designed to replace IPv4 because IPv4 addresses were running out. It provides massive address space, better security, and improved performance.
- Created to replace IPv4 due to address shortage
- 128-bit address
- Written in hexadecimal format. Example: 2401:4900:1688:1020:abcd:0099:0000:1234
- Total possible addresses: 340 undecillion (almost unlimited).
- Provides better:Security, Speed, Auto-configuration, Efficiency.
- No need for NAT due to huge address space