COMPUTER NETWORK VERY IMPORTANT QUESTIONS WITH SOLUTION FOR CLASS 12

Section A: Multiple Choice Questions (MCQs)

1. Which of the following is not a type of network topology?

   • a) Star
   • b) Bus
   • c) Ring
   • d) Node
     Answer: d) Node

2. What does LAN stand for?

   • a) Large Area Network
   • b) Local Area Network
   • c) Long Area Network
   • d) Light Area Network
     Answer: b) Local Area Network

3. Which protocol is used to send an email?

   • a) HTTP
   • b) FTP
   • c) SMTP
   • d) POP
     Answer: c) SMTP

4. The device that connects multiple networks together is called:

   • a) Hub
   • b) Switch
   • c) Router
   • d) Repeater
     Answer: c) Router

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Section B: Short Answer Questions

1. Define the term "Computer Network".
   Answer: A computer network is a collection of interconnected devices that communicate with each other and share resources like files, printers, and internet connections. The primary purpose of a network is to enable communication and data sharing among devices.

2. What is the difference between a Hub and a Switch?
   Answer:

   • A Hub is a basic networking device that connects multiple devices in a network, broadcasting data to all devices connected to it. It operates at the physical layer of the OSI model.
   • A Switch is more advanced, forwarding data only to the device that needs it based on MAC addresses. It operates at the data link layer of the OSI model.

3. Explain the concept of IP Address.
   Answer: An IP address is a unique identifier assigned to each device connected to a network. It allows devices to communicate with each other over the internet or a local network. IP addresses can be IPv4 (e.g., 192.168.1.1) or IPv6 (e.g., 2001:0db8:85a3:0000:0000:8a2e:0370:7334).

4. What are the advantages and disadvantages of a Star Topology?
   Answer:

• Advantages:
  • Easy to install and manage.
  • If one device fails, it doesn’t affect the rest of the network.
  • Easy to add new devices.
• Disadvantages:
• If the central hub/switch fails, the entire network goes down.
• More cable is required compared to other topologies like bus or ring.

5. Differentiate between IPv4 and IPv6.
   Answer:

   • IPv4:
     • 32-bit address scheme, allowing for 4.3 billion unique addresses.
     • Written in decimal format, e.g., 192.168.1.1.
     • Supports broadcast, multicast, and unicast communication.
   • IPv6:
     • 128-bit address scheme, allowing for an enormous number of unique addresses.
     • Written in hexadecimal format, e.g., 2001:0db8:85a3:0000:0000:8a2e:0370:7334.
     • Supports more efficient routing and offers better security features.

6. Discuss the various types of network topologies with diagrams.
   Answer:

   • Bus Topology: All devices are connected to a single central cable (bus). Data travels along the bus, and all devices receive the data, but only the intended recipient accepts it. Diagram: A straight line with devices connected along it.
   • Star Topology: All devices are connected to a central hub or switch. Data from one device is sent to the hub and then forwarded to the intended recipient. Diagram: A central point (hub/switch) with lines radiating out to devices.
   • Ring Topology: Devices are connected in a circular formation. Data travels in one direction around the ring until it reaches its destination. Diagram: A circle with devices connected along it.
   • Mesh Topology: Every device is connected to every other device in the network. This provides high redundancy and reliability. Diagram: Multiple interconnected lines, forming a mesh-like structure.

7. What are the security measures that can be implemented in a network?
   Answer:

   • Firewalls: Act as a barrier between trusted and untrusted networks, filtering traffic based on predefined rules.
   • Encryption: Secures data by converting it into an unreadable format, ensuring that only authorized parties can access it.
   • Antivirus and Anti-malware: Protects networked devices from malicious software.
   • Intrusion Detection Systems (IDS): Monitors network traffic for suspicious activity and alerts administrators.
   • Access Control: Restricts access to network resources based on user roles and permissions.

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Section D: Practical Application

1. Set up a simple LAN in your school computer lab.
   Answer:

   • Steps:
     1. Connect all computers to a switch using Ethernet cables.
     2. Assign IP addresses to each computer, either manually or using DHCP.
     3. Configure the switch to manage data traffic between computers.
     4. Set up file sharing and printers on the network.
     5. Test the network by sharing files and accessing shared resources.

2. Analyze the following scenario:

   • Scenario: Your school is planning to upgrade its network infrastructure. Write a proposal outlining the type of network topology you would recommend, including the choice of devices and security measures.
     Answer:
   • Topology: Recommend a Star Topology for its ease of management and scalability.
   • Devices: Use switches to connect devices within classrooms, routers to connect different segments of the network, and a firewall to secure the network.
   • Security: Implement a firewall, use strong encryption for data transmission, and employ antivirus software on all connected devices. Set up VLANs to segment the network and control access.

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Section E: Case Study

Read the following case study and answer the questions:

XYZ Corporation has a growing number of employees who need to access the company’s database from remote locations. The company is considering implementing a VPN to ensure secure access.

1. What is a VPN, and how does it work?
   Answer: A VPN (Virtual Private Network) is a secure network connection over the internet that encrypts data, allowing remote users to access the corporate network as if they were directly connected. It provides privacy and security by masking the user's IP address and encrypting all transmitted data.

2. Discuss the benefits and potential drawbacks of using a VPN in this scenario.
   Answer:

   • Benefits:
     • Secure remote access to the corporate network.
     • Encryption of sensitive data during transmission.
     • Ability to work from any location with internet access.
   • Drawbacks:
     • Can slow down internet speed due to encryption overhead.
     • Requires proper configuration and maintenance to avoid security vulnerabilities.