The internet has become an integral part of our lives, connecting us to vast amounts of information and enabling communication across the globe. But have you ever wondered how internet addresses are organized, how we connect to the internet, and what role the Domain Name System (DNS) plays? In this article, we will delve into these topics and provide you with a comprehensive understanding.

Introduction

The internet is a vast network that connects billions of devices worldwide. To facilitate communication and data exchange, every device connected to the internet is assigned a unique identification number called an IP address.

(a) Internet Addresses and Organization

IP Address

An IP address, short for Internet Protocol address, is a numerical label assigned to each device connected to a computer network. It serves two primary functions: identifying the host or network interface and providing the location addressing.

For example, let’s say you want to access a website. When you enter the website’s URL in your web browser, your device communicates with a DNS server to obtain the IP address associated with that domain. This IP address is crucial for establishing a connection and retrieving the requested information.

Domain Names

While IP addresses are crucial for communication between devices, they are not easily memorable for humans. This is where domain names come into play. A domain name is a user-friendly, alphanumeric representation of an IP address.

For instance, instead of typing “74.125.224.72” to access Google’s search engine, we simply enter “google.com.” Domain names make it easier for us to navigate the internet and remember the web addresses of our favorite websites.

Top-Level Domains

Domain names are organized into a hierarchical structure known as the Domain Name System (DNS). At the top level, we have generic top-level domains (gTLDs) such as .com, .org, and .net. These gTLDs represent different categories of websites, organizations, and networks.

For example, a domain name ending with .com indicates that the website belongs to a commercial entity, while .org suggests an organization or non-profit. Each top-level domain serves as a categorization system, helping users identify the purpose or nature of a website.

Domain Name System (DNS)

The DNS acts as a phone book for the internet, translating domain names into their corresponding IP addresses. When you enter a domain name in your web browser, your device sends a request to a DNS server, which returns the IP address associated with that domain. This enables your device to establish a connection and retrieve the requested information.

For instance, if you type “apple.com” in your browser, the DNS server will provide your device with the IP address associated with Apple’s website. This IP address allows your device to communicate directly with the web server hosting Apple’s site, enabling you to access their content. Modes of Connecting to the Internet

(b) Connection Modes

Dial-Up Connection

Dial-up connections were one of the earliest methods of accessing the internet. They involve using a telephone line and a modem to establish a connection. While dial-up connections are slow and less common nowadays, they played a significant role in the early days of internet adoption.

Imagine the screeching sound of a dial-up modem connecting to the internet and the patience required as web pages loaded slowly, one element at a time. Dial-up connections had limited bandwidth, making it challenging to stream media or engage in bandwidth-intensive activities.

Broadband Connection

Broadband connections provide high-speed internet access and are the norm for most users today. They offer faster data transfer rates and can be delivered via various technologies such as Digital Subscriber Line (DSL), cable, or fiber optics.

DSL connections utilize existing telephone lines to transmit data, while cable connections use coaxial cables originally designed for television signals. Fiber optic connections, on the other hand, use thin strands of glass or plastic to transmit data as pulses of light. Fiber optic connections are known for their ultra-fast speeds and reliability.

With broadband connections, you can enjoy seamless streaming, online gaming, and faster downloads. These connections have revolutionized how we interact with the internet, allowing for more immersive and bandwidth-intensive online experiences.

Wireless Connection

Wireless connections allow users to access the internet without the need for physical cables. Wi-Fi networks, cellular data networks, and satellite connections are some examples of wireless connectivity options.

Wi-Fi networks are prevalent in homes, offices, and public places, providing convenient internet access for devices such as laptops, smartphones, and tablets. Cellular data networks, powered by mobile network providers, allow users to connect to the internet using their mobile devices.

Satellite connections, although less common in urban areas, provide internet access in remote or rural locations where terrestrial connections may be limited or unavailable.

Wireless connections have significantly increased our mobility and accessibility to the internet. We can now browse the web, check emails, and connect with others from almost anywhere, as long as we have a compatible device and access to a wireless network.

Fiber Optic Connection

Fiber optic connections are known for their ultra-fast speeds and reliability. They use optical fibers to transmit data using light signals, enabling rapid transfer rates and low latency.

Compared to traditional copper-based connections like DSL or cable, fiber optic connections offer significantly higher bandwidth, allowing for quicker downloads, smoother streaming, and faster response times.

Fiber optic connections are particularly beneficial in scenarios where large amounts of data need to be transmitted quickly, such as online gaming, video conferencing, or downloading high-definition content.

(c) Purpose of DNS in the Internet

The DNS plays a crucial role in facilitating internet navigation and accessibility. Its primary purposes include:

Translation of Domain Names

DNS translates user-friendly domain names into machine-readable IP addresses, allowing devices to establish connections based on domain names.

For example, when you type “youtube.com” in your browser’s address bar, the DNS resolves the domain name to the IP address of YouTube’s servers, enabling your device to connect and stream videos.

Load Balancing

DNS can distribute incoming traffic across multiple servers, helping to balance the load and ensure optimal performance for websites and online services.

Large websites with heavy traffic, such as e-commerce platforms or social media networks, often employ multiple servers to handle user requests. The DNS can direct incoming requests to different servers, evenly distributing the load and preventing any single server from becoming overwhelmed.

Redundancy and Failover

By assigning multiple IP addresses to a single domain name, DNS enables failover and redundancy. If one server becomes unavailable, the DNS can direct traffic to an alternative IP address.

For instance, if a particular web server experiences technical issues or goes offline, the DNS can route incoming requests to a backup server. This ensures that users can still access the website even if one server is temporarily inaccessible.

Caching

DNS servers store recently accessed translations in their cache, reducing the time it takes to resolve domain names and improving overall network performance.

When a DNS server receives a request for a domain name, it checks its cache first to see if it has recently resolved that domain. If the information is available, the server can provide the IP address without having to perform a new lookup. Caching helps expedite the process, resulting in faster response times for frequently visited websites.

By fulfilling these purposes, the DNS enables efficient and seamless communication across the internet, making it easier for users to access websites, services, and online resources.

ITM-2022

Q.7

Answer the following questions in brief:

(a) Give an introduction of Web Servers and name some popular web servers.

(b) Describe the access and usage of any one of the web servers.

Q.8

(a) Describe the threats and attacks to which the Internet may be vulnerable.

(b) What is the role of encryption, digital signature and firewalls in the context of network security?

Learn Loner

Answering Internet Address Organization, Connection Modes, and the Purpose of DNS

Table of contents