Imagine you want to send a letter to a friend who lives in another city. To make sure the letter reaches them, you need to write their address on the envelope. Similarly, in the world of computers and the internet, devices need a distinct address to send and receive information. This address is called an IP address, which stands for Internet Protocol address.

An IP address is like a digital tag for a device connected to the internet, such as a computer, smartphone, or tablet. It helps in identifying and locating the device so that information can be sent to it. IP addresses are made up of a series of numbers separated by dots. It's like a phone number for devices on the internet.

Every device connected to the internet needs an IP address, just as every house needs a physical address. When you access a website, send an email, or watch a video online, your device uses its IP address to communicate with other devices and servers around the world.

IP addresses are assigned by Internet Service Providers (ISPs), which are companies that provide Internet access. When you connect to the internet, your ISP gives your device an IP address so that it can communicate with other devices and access online services.

IP addresses are important for many things. They allow you to visit websites by typing in their domain names (like www.kaptainjamjam.com) instead of long, complicated numbers. They also help in delivering emails, streaming videos, and downloading files. IP addresses are like invisible highways that connect devices and make the internet work. It's important to note that IP addresses don't reveal personal information about you, like your name or physical address. They simply identify your device and its location on the internet.

Types of IP Addresses:

a. IPv4 Addresses: The most used type, IPv4 addresses consist of four sets of numbers separated by dots (e.g 192.168.0.1). However, due to the rapid growth of the internet, the available pool of IPv4 addresses has been exhausted.

b. IPv6 Addresses: With the aim of addressing the IPv4 depletion issue, IPv6 addresses were introduced. They are represented in a hexadecimal format and offer a significantly larger address space to accommodate the expanding number of devices.

IP Address Allocation:

a. Dynamic IP Addresses: Internet Service Providers (ISPs) often assign dynamic IP addresses, which are temporary and subject to change. This allocation method allows ISPs to efficiently manage their address pools.

b. Static IP Addresses: Certain devices, such as servers or network printers, require a consistent IP address. Static IP addresses are manually configured and remain unchanged over an extended period.

To find the IP address for a device, you can follow these steps:

- Windows:

a. Click on the "Start" button and type "Command Prompt" in the search bar.

b. Open the Command Prompt application.

c. In the Command Prompt window, type "ipconfig" and press Enter.

d. Look for the "IPv4 Address" or "IP Address" listed under the network adapter that you are using. This is the IP address of your device.

- macOS:

a. Click on the Apple menu in the top-left corner and select "System Preferences."

b. In the System Preferences window, click on "Network."

c. Select the network connection you are using (e.g., Wi-Fi, Ethernet) from the left sidebar.

d. The IP address will be displayed on the right side, labeled as "IPv4 Address" or "IP Address."

- Android:

a. Open the "Settings" app on your Android device.

b. Scroll down and tap on "Wi-Fi" or "Connections," depending on your device.

c. Find your currently connected network and tap on it.

d. In the network details, the IP address should be listed under the "IP address" section.

- iOS (iPhone/iPad):

a. Open the "Settings" app on your iOS device.

b. Tap on "Wi-Fi."

c. Locate the Wi-Fi network you are connected to and tap the "i" icon next to it.

d. The IP address will be displayed under the "IPv4 Address" section.

- Linux (Ubuntu):

a. Open the terminal application.

b. Type the command "ip addr show" and press Enter.

c. Look for the network interface you are using (e.g., eth0, wlan0) and find the associated IP address.

These steps provide general instructions for finding the IP address on different operating systems. However, the exact process may vary depending on the device and operating system version you are using.

Usable and Unusable IP Addresses

In the world of networking, not all IP addresses are available for use. Some addresses are reserved for specific purposes, while others are designated as unusable due to technical or administrative reasons.

Usable IP Address Ranges:

• Private IP Addresses:

Private IP addresses are reserved for local networks and are not routable on the internet. The most used private address ranges are:

10.0.0.0 to 10.255.255.255, 172.16.0.0 to 172.31.255.255, 192.168.0.0 to 192.168.255.255

• Public IP Addresses:

Public IP addresses are globally unique and can be accessed over the internet. They are assigned by Internet Assigned Numbers Authority (IANA) to Internet Service Providers (ISPs) and organizations. Public IPv6 addresses are also globally unique and assigned to ISPs and organizations.

Unusable IP Address Ranges:

The broadcast address is the highest address within a network. It is used to send a packet to all devices on that network simultaneously. In IPv4, the broadcast address is typically the last address in the network range i.e 192.168.255.255. IPv6 does not use traditional broadcast addresses. Instead, multicast addresses are used for similar purposes.

In both IPv4 and IPv6, the network and subnet identifiers have specific values that are not assigned to individual devices. These identifiers play a crucial role in network routing and subnetting.

Certain IP address ranges remain unallocated or reserved for future use, ensuring the scalability and growth of the internet. These ranges are managed by IANA and regional Internet registries.

SUBNETTING

Imagine you have a big garden that you want to divide into smaller sections to make it easier to manage. Each section will have its purpose, like growing vegetables, flowers, or have a play area. This way, you can organize and take care of each section more efficiently. Subnetting in computer networks is quite similar.

Subnetting is a technique used in computer networks to divide a large network into smaller parts called subnets. It helps organize and manage the network better, just like dividing a garden into smaller sections. Each subnet can have its own purpose or specific devices connected to it.

In computer networks, devices are assigned unique addresses called IP addresses, which are like the postal addresses of the devices. Subnetting allows us to divide a range of IP addresses into smaller ranges. It's like splitting a big cake into smaller slices.

By subnetting, we can achieve a few important things:

Efficient Address Usage: Imagine you have a big box of chocolates, and you want to share it with your friends. Instead of giving the entire box to one friend, you can divide the chocolates into smaller bags and give one bag to each friend. Similarly, with subnetting, we can divide a large range of IP addresses into smaller ranges, ensuring that each subnet has just enough addresses for the devices connected to it. This helps in the efficient use of IP addresses.

Improved Performance: Subnetting also helps in improving network performance. Imagine you are hosting a party in your garden. If everyone is gathered in one big group, it might be crowded and chaotic. But if you divide the garden into smaller sections, people can spread out, socialize, and move around more easily. Similarly, by dividing a large network into subnets, we can reduce congestion and improve the performance of the network.

Enhanced Security: Subnetting can also enhance network security. Imagine you have valuable items in your house, and you want to keep them separate from the common areas. You can create a locked room or a safe to keep those items secure. Similarly, with subnetting, we can isolate sensitive devices or systems from the rest of the network, making it more difficult for unauthorized access or attacks to occur.

Subnetting Concepts:

a. Subnet Mask: A subnet mask is a 32-bit value used to identify the network portion and the host portion of an IP address. It defines the boundary between the two parts and determines the number of available subnets and hosts in a subnet.

b. Network ID and Host ID: In subnetting, the network ID represents the portion of the IP address that identifies the specific subnet, while the host ID identifies the individual devices within that subnet.

c. CIDR Notation: Classless Inter-Domain Routing (CIDR) notation is commonly used in subnetting to represent the subnet mask in a compact format.