WHAT IS IP? DETAILS ABOUT IP INCLUDING TCP/IP

 

Introduction

The full form of ip is internet protocol.The internet functions on the principle of communication between devices. IP addressing plays a crucial role in this process, acting as a unique identifier for each device on a network. This assignment will explore the fundamental concepts of IP addressing and delve into its various classifications with the help of examples.

What is an IP Address?

An IP address, short for Internet Protocol address, is a unique numerical label assigned to a device connected to a network. It functions like a postal address in the digital world, enabling data packets to be routed to the correct destination device. IP addresses are typically written in a dotted decimal format consisting of four numbers, each ranging from 0 to 255. Here's an example:

• 192.168.1.1

IP Version: IPv4 vs. IPv6

There are two main versions of IP addresses currently in use:

·        IPv4 (Internet Protocol Version 4): This is the most widely used version, but due to its limited address space, it's gradually being phased out.

·        IPv6 (Internet Protocol Version 6): This is the newer version designed to address the limitations of IPv4. It offers a significantly larger address space, catering to the ever-growing number of internet devices.

Classification of IP Addresses

IP addresses can be classified based on two main aspects:

1. Scope (Public vs. Private):

·        Public IP Addresses: These addresses are unique and identifiable on the global internet. They are assigned to devices that need to be accessed from outside a local network, like web servers or email servers. An example of a public IP address could be 66.249.93.104 (Note: This is a real example, but it may change over time).

·        Private IP Addresses: These addresses are not routable on the public internet. They are used for internal communication within a private network, like a home network or office network. Common private IP address ranges include 192.168.0.0 - 192.168.255.255 and 10.0.0.0 - 10.255.255.255.

 

 

IP Address Classes and Classification Methods

There are traditionally five classes of IP addresses in IPv4 (Internet Protocol version 4), although class E is reserved for future use. Each class allocates a different number of networks and hosts based on the number of bits used for the network portion of the address. Here's a breakdown:

• Class A (0 - 127):
• Identifies large networks with a limited number of hosts.
• Uses the first 8 bits (1 octet) for the network address, leaving 24 bits for host addressing.
• Example: 10.0.0.1 (Class A network with a host address within that network)
• Class B (128 - 191):
• Identifies medium-sized networks with a moderate number of hosts.
• Uses the first 16 bits (2 octets) for the network address, leaving 16 bits for host addressing.
• Example: 172.16.0.5 (Class B network with a host address within that network)
• Class C (192 - 223):
• Identifies smaller networks with a large number of potential hosts.
• Uses the first 24 bits (3 octets) for the network address, leaving 8 bits for host addressing.
• Example: 192.168.1.20 (Class C network with a host address within that network)
• Class D (224 - 239):
• Used for multicast addressing, where a single message is sent to a group of devices.
• Not used for traditional network addressing.
• Class E (240 - 255):
• Reserved for future use.

Finding the IP Class

There are two main methods to identify the class of an IP address:

1.     Looking at the First Octet (in Decimal):

• Class A: Range 0 to 127
• Class B: Range 128 to 191
• Class C: Range 192 to 223

2.     Examining the Leading Binary Bits:

• Class A: Starts with 0 (binary)
• Class B: Starts with 10 (binary)
• Class C: Starts with 110 (binary)

Note: Due to the depletion of IPv4 addresses, a scheme called Classless Inter-Domain Routing (CIDR) is now widely used. CIDR allows for more flexible subnet mask allocation, making classful identification less relevant in modern networking. However, understanding the traditional class system is still valuable for foundational knowledge of IP addressing.

 

2. Assignment (Static vs. Dynamic):

·        Static IP Addresses: These addresses are manually assigned to a device and remain constant. They are typically used for servers or other devices that need to be consistently reachable from the internet.

·        Dynamic IP Addresses: These addresses are automatically assigned to a device by a DHCP (Dynamic Host Configuration Protocol) server. They are commonly used for home networks and change periodically.

Examples

Here's a table summarizing the classifications with examples:

Classification	Description	Example
Public IP	Identifiable on the global internet	66.249.93.104 (This is a real example, but it may change over time)
Private IP	Used for internal communication	192.168.1.100
Static IP	Manually assigned, remains constant	Used for a web server (e.g., 172.20.0.2)
Dynamic IP	Automatically assigned by DHCP server	Assigned to your home computer (e.g., 10.0.0.50)

  The OSI model, also known as the Open Systems Interconnection model, is a conceptual framework used to describe the communication process between network devices. It defines seven layers, each with specific functionalities that work together to ensure successful data transmission. Here's a breakdown of the OSI model and its classifications:

Layers of the OSI Model

1. Physical Layer: Deals with the physical transmission of data bits across a network medium like cables or wireless signals. (Example: Cables, connectors)
2. Data Link Layer: Handles error detection and correction at the frame level, ensuring reliable data transfer between network devices. (Example: MAC addresses, error checking protocols)
3. Network Layer: Responsible for routing packets across networks, determining the best path for data to reach its destination. (Example: IP addresses, routing protocols)
4. Transport Layer: Provides reliable data transfer between applications on different devices, managing data flow and error recovery. (Example: TCP, UDP protocols)
5. Session Layer: Establishes, manages, and terminates sessions between communicating applications. (Example: Session initiation protocols)
6. Presentation Layer: Focuses on data presentation, including encryption, decryption, and data format conversion. (Example: Encryption algorithms, data compression)
7. Application Layer: Provides network services directly to user applications, like web browsing, email, and file transfer. (Example: HTTP, FTP protocols)

Classifications of the OSI Model

The OSI model can be classified into two groups based on their interaction with the physical network medium:

• Lower Layers (Physical & Data Link): These layers interact directly with the physical network medium, dealing with the physical transmission and addressing of data packets.
• Upper Layers (Network through Application): These layers focus on higher-level functionalities like routing, reliable data transfer, data presentation, and providing services to user applications. They don't directly interact with the physical network medium and rely on the lower layers for data transmission.

Benefits of the OSI Model

The OSI model offers several advantages:

• Standardization: Provides a common reference point for network communication, facilitating interoperability between different devices and software.
• Problem Isolation: Allows troubleshooting network issues by isolating problems to specific layers.
• Modular Design: Enables independent development and improvement of each layer without affecting others.

Remember:

• The OSI model is a conceptual framework, not a strict implementation. Real-world protocols may combine functionalities from different layers.
• Understanding the OSI model helps visualize the complex process of network communication and troubleshoot issues more effectively.

 

Private vs. Public IP Addresses: Understanding the Divide

Both public and private IP addresses play crucial roles in network connectivity, but they serve distinct purposes. Here's a breakdown of their differences:

Public IP Address

• Function: Acts as your home address on the internet. It identifies your network to the wider internet, allowing devices outside your local network to access resources like web servers or email servers on your network.
• Uniqueness: Public IP addresses are unique and globally routable. No two devices on the internet should have the same public IP address at a given time.
• Assignment: Typically assigned by your Internet Service Provider (ISP) and may change periodically depending on your service plan.
• Accessibility: Public IP addresses are visible to anyone on the internet.

Private IP Address

• Function: Functions like a local address within your private network, similar to a street address within a town. It identifies devices on your network and allows them to communicate with each other.
• Uniqueness: Private IP addresses are not unique across the internet. Multiple devices on different private networks can have the same private IP address.
• Assignment: Assigned by your router to devices on your network. Private IP addresses are not routable on the public internet.
• Accessibility: Not directly accessible from the public internet. Devices outside your network cannot directly connect to devices using only their private IP addresses.

Finding Your IP Address

There are different ways to find your public and private IP addresses:

• Public IP Address:
• Search online using services like "https://support.google.com/fiber/answer/2899098?hl=en". These websites will display your public IP address as seen from the internet.
• Private IP Address:
• Windows: Open Command Prompt and type ipconfig. Look for the line labeled "IPv4 Address" under the network adapter you're using (e.g., Wi-Fi or Ethernet).
• Mac: Go to System Preferences > Network. Select your network connection and click on "Advanced." Under the TCP/IP tab, look for the "IPv4 Address."

In summary:

• Public IP addresses are like your house number on a public street, visible from anywhere.
• Private IP addresses are like apartment numbers within a building, only relevant for communication within your local network.

TCP:

TCP and IP are both fundamental protocols that work together to enable reliable communication over networks like the internet. However, they serve distinct purposes:

TCP (Transmission Control Protocol):

• Function: TCP is responsible for ensuring reliable and ordered data delivery between applications on different devices. It establishes a connection between sender and receiver, breaks down data into manageable packets, transmits them, acknowledges receipt, and retransmits lost packets if necessary.
• Key Features:
• Connection-oriented: Establishes a connection before data transfer, similar to a phone call.
• Reliable delivery: Guarantees data arrives in the correct order and without errors.
• Flow control: Manages the data flow rate to prevent overwhelming the receiver.
• Error checking: Uses checksums and acknowledgments to verify data integrity.

IP (Internet Protocol):

• Function: IP acts as the addressing and routing layer. It assigns unique IP addresses to devices and defines the format of data packets. IP is responsible for routing these packets across networks based on their destination IP address, similar to how mail is addressed and delivered.
• Key Features:
• Connectionless: Sends data packets independently without establishing a connection.
• Best-effort delivery: Makes a delivery attempt but doesn't guarantee success.
• Packet-based: Breaks down data into packets for efficient transmission.
• Addressing: Assigns IP addresses for identification and routing.

Here's an analogy to understand the difference:

• Imagine sending a letter (data) to a friend (receiver) across town (network).
• TCP: You establish a phone call with your friend (connection) to confirm their address (IP address) and agree on how many pieces you'll send the letter in (data packets). You then carefully tear the letter into numbered pieces, mail them one by one (send packets), and call your friend to confirm they received everything in order and without mistakes (error checking and retransmission).
• IP: You simply write the address (IP address) on the envelope (packet header) and drop it in the mailbox (network). The mail service (network infrastructure) will deliver it (hopefully) to your friend's mailbox (receiver's IP address), but you don't necessarily know if it arrives or in what condition (connectionless and best-effort delivery).

In essence:

• TCP provides reliable data transfer with error checking and guarantees delivery, acting like a controlled and secure communication channel.
• IP focuses on efficient data routing based on addresses, functioning like a delivery system that gets the data packets to the right destination.

TCP and IP work together seamlessly. TCP relies on IP to address and route data packets, while IP utilizes TCP's reliability features when needed (e.g., web browsing, file transfer).

 

What is the use of proxy?

A proxy server acts as an intermediary between a client device (such as a computer or smartphone) and the internet. It facilitates communication between the client and other servers on the internet. Here are several key uses of proxies:

 

1. Anonymity and Privacy:

   Proxies can mask the IP address of the client device, thereby providing a level of anonymity and privacy. When requests are sent through a proxy server, the target server sees the IP address of the proxy server rather than the client's IP address. This can be useful for individuals who want to browse the internet anonymously or bypass geo-restrictions.

 

2. Content Filtering and Access Control:

   Organizations often use proxies to enforce content filtering and access control policies. By routing internet traffic through a proxy server, organizations can monitor and control which websites and online services their employees can access. This helps improve productivity, prevent access to malicious websites, and ensure compliance with company policies.

 

3. Caching:

   Proxies can cache frequently accessed web content, such as web pages, images, and files. When a client requests content that is already cached by the proxy server, the server can serve the content directly from its cache rather than fetching it from the internet again. This reduces bandwidth usage and improves web browsing performance for users.

 

4. Load Balancing:

   In large-scale web environments, proxies can be used for load balancing purposes. Multiple backend servers can be configured behind a proxy server, and incoming client requests can be distributed among these servers based on factors such as server load, geographic location, or other criteria. This helps distribute incoming traffic evenly across server resources and improves the overall performance and reliability of the system.

 

5. Security and Firewall Protection:

   Proxies can serve as an additional layer of security between internal networks and the internet. They can inspect incoming and outgoing traffic, filter out malicious content, and block access to known malicious websites. Proxies can also act as a firewall by enforcing security policies and blocking unauthorized access attempts to internal networks.

 

6. Bypassing Geo-Restrictions:

   Proxies can be used to bypass geo-restrictions imposed by websites and online services. By routing internet traffic through a proxy server located in a different geographic region, users can access content that may be blocked or restricted in their own country.

 

Overall, proxies serve a variety of purposes, including enhancing privacy, improving performance, enforcing security policies, and bypassing restrictions. Their versatility makes them valuable tools for both individuals and organizations in managing their internet connectivity and resources.

Conclusion

Understanding IP addressing is fundamental for anyone who interacts with the internet. By recognizing the different classifications and their purposes, you can gain a deeper understanding of how devices communicate and navigate the vast digital landscape.

Further Exploration

This assignment provides a basic understanding of IP addressing. You can further explore topics like:

• Subnetting: Dividing a network into smaller segments
• Domain Name System (DNS): Translating domain names into IP addresses

By delving deeper, you'll gain a more comprehensive understanding of how the internet functions.