Introduction to Computer Network: SEBA Class 10 Computer notes

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Get answers, questions, notes, textbook solutions, extras, pdf, mcqs for Computer chapter 1 Introduction to Computer Network of class 10 (HSLC/Madhyamik) for students studying under the Board of Secondary Education, Assam (SEBA). These notes/answers, however, should only be used for references and modifications/changes can be made wherever possible.

Introduction

Computer networks enable the efficient sharing of information and resources among interconnected devices, utilizing a variety of wired and wireless technologies. Wired connections include coaxial cable, twisted pair cable, and optical fiber cable, while wireless technologies encompass Bluetooth, Wi-Fi, and WiMAX. These networks can be classified as wired, wireless, or hybrid depending on the connecting technology employed. Additionally, the size of the network plays a crucial role in its classification, with four main types being PAN (Personal Area Network), LAN (Local Area Network), MAN (Metropolitan Area Network), and WAN (Wide Area Network). By integrating these diverse technologies and network sizes, computer networks facilitate seamless communication and resource sharing, greatly enhancing productivity and connectivity in various settings.

Textual questions and answers

I. Fill in the blanks

1. The hostname command is used to display _____

Answer: computer name

2. The length of a IPv4 and a IPv6 is _____ and _____ bytes respectively.

Answer: 32, 128

3. An access point is used to connect _____

Answer: wireless devices to a wired network

4. The ping command is used to _____

Answer: test the connectivity between two devices

5. HTTPS transfer _____ data.

Answer: encrypted

II. Multiple choice questions

1. Which device is required to connect multiple heterogeneous networks?

A) Hub B) Switch C) Router D) Access Point 

Answer: C) Router

2. Which is the largest type of computer network?

A) PAN B) LAN C) MAN D) WAN

Answer: D) WAN

3. Which protocol transfers encrypted data instead of plain data?

A) HTTP B) HTTPS C) FTP D) SMTP

Answer: B) HTTPS

4. How many bytes are reserved for OUI in a MAC address? 

A) 3 B) 8 C) 24 D) 12

Answer: A) 3

5. IP address can be automatically assigned if the network is connected with 

A) Access Point B) Mail Server C) Web Server D) DHCP Server

Answer: D) DHCP Server

III. Short answer questions

1. Mention the name of components required to set up a MAN network. Draw a block diagram of a MAN network labeling name of each component. (Hint: MAN network is a connection of multiple LAN)

Answer: To set up a Metropolitan Area Network (MAN), the following components are required:

– Multiple Local Area Networks (LANs)
– Routers or switches for interconnecting the LANs
– Optical Fiber Cable for physical connection

2. Why hostname should not be used to identify a computer in a computer network?

Answer: A hostname may not be unique always, which means that there is a possibility that two or more computers in a computer network may have the same hostname. Therefore, using a hostname to identify a computer in a computer network may lead to confusion and errors. Instead, IP addresses can be considered as unique identifiers of a computer in a computer network.

3. Give five examples of valid and five examples of invalid IPv4 addresses. (Hint: Each segment of an IPv4 address has a fixed length)

Answer: Five examples of valid IPv4 addresses are:

192.168.0.1
172.16.0.0
10.0.0.0
255.255.255.255
172.31.255.255

Five examples of invalid IPv4 addresses are:

256.0.0.0
172.16.0.256
10.0.0.1.2
172.31.256.255
172.16.0.00

4. Can we compare HTTP and FTP protocols? Mention their functionality.

Answer: HTTP (Hypertext Transfer Protocol) is used for fetching web resources such as HTML documents or other web pages. It is a client-server protocol where a client requests a web resource using HTTP protocol and web server provides that resource to the client. HTTP is used for accessing and transmitting web pages over the internet.

FTP (File Transfer Protocol) is used for transmitting files from one computer to another over a network. FTP allows a user to move around different directories of the server, download files, upload files, delete files, etc. FTP is used for transferring files between computers.

The main difference between HTTP and FTP protocols is their functionality. HTTP is used for accessing and transmitting web pages over the internet, while FTP is used for transferring files between computers. Additionally, HTTP is a client-server protocol, whereas FTP is a peer-to-peer protocol. Another significant difference is that HTTP is designed for accessing and transmitting web pages, whereas FTP is designed for transmitting files.

5. How many 16 port switches are required to connect 31 computers in a network? (Hint: To connect all computers, all switches also should be connected among themselves)

Answer: To connect 31 computers in a network using 16 port switches, we need 2 switches.

Extra/additional questions and answers

1. What is a computer network?  

Answer: A computer network is a set of computers and other units that are connected with each other, allowing information or resources to be shared among connected computers.

2. Give two examples of wired and wireless technologies.  

Answer:

• Wired technologies: Coaxial cable, Twisted pair cable, Optical Fiber Cable
• Wireless technologies: Bluetooth, Wi-Fi, WiMAX

3. How can a computer network be classified based on connecting technology?  

Answer: Based on the connecting technology, a computer network can be classified as wired, wireless, or hybrid.

Q. List the four main types of computer networks based on the size of the network.  

Answer:

• PAN (Personal Area Network)
• LAN (Local Area Network)
• MAN (Metropolitan Area Network)
• WAN (Wide Area Network)

Q. What is a Personal Area Network (PAN) and provide an example of its use?  

Answer: A Personal Area Network (PAN) is the simplest computer network, usually set up for individual use within a limited geographical range. An example of its use is setting up a network between a laptop and other electronic gadgets like a smartphone, PDA, tablet, or printer.

Q. What is the typical network range of a Personal Area Network (PAN)?  

Answer: The typical network range of a Personal Area Network (PAN) is about 10 meters from a central device to the other communicating devices.

Q. What is a Local Area Network (LAN) and where can you observe such networks?  

Answer: A Local Area Network (LAN) is a network where a number of units are connected to each other in a small area such as a building, office, etc. with the help of a common communication path like a switch or a similar connecting device. You can observe such networks in banks, cyber cafes, or school laboratories.

Q. How can resources be shared in a LAN? Provide an example.  

Answer: In a LAN, resources like internet connection or network printers can be shared among connected devices. For example, if there is a LAN in a school, only one internet connection can be shared by all computers in the school, eliminating the need for individual internet connections.

Q. What is a Metropolitan Area Network (MAN) and how is it formed?  

Answer: A Metropolitan Area Network (MAN) is a network that is spread over an entire city or a wide geographic location, covering a larger area than that of a LAN. A MAN is formed by interconnecting multiple LANs within a limited geographic area.

Q. Explain the role of Internet Service Providers (ISPs) in MANs.  

Answer: ISPs play a crucial role in MANs by providing high-speed internet connections to multiple organizations, such as connecting a college LAN, an office LAN, and a hospital LAN at different locations, using Optical Fiber Cable to establish the physical connection and achieve good quality of service.

Q. Define Wide Area Network (WAN) and provide an example.  

Answer: A Wide Area Network (WAN) is a network formed by connecting devices from multiple locations across the globe, often established with Leased Telecommunication Circuits. The Internet is an example of a WAN since it is spread over the world.

Q. How can a computer be identified in a network?  

Answer: A computer in a network can be identified by its hostname, IP address, or MAC address.

Q. What is a hostname and what is its purpose in a computer network?  

Answer: The hostname is the name of a computer or any connected device in a computer network. It is used to distinguish a device within a computer network.

Q. How can you find the hostname of a computer in Windows, Linux, and Mac operating systems?  

Answer: You can find the hostname of your computer in the command prompt in the Windows, Linux, and Mac operating systems by using the command “hostname”.

Q. How can you change the hostname of a computer in Windows 10 and Linux operating systems?  

Answer:

• In Windows 10, you can change the hostname by navigating to the “Rename PC” option.
• In Linux operating systems, you can change the hostname by modifying the content of the “hostname” file in the “etc” directory.

Q. Why should the hostname not be considered as a unique identifier of a computer in a computer network?  

Answer: The hostname should not be considered as a unique identifier of a computer in a computer network because hostnames may not always be unique. Two or more computers in a network may have the same hostname if users assign the same hostname to their computers intentionally or unintentionally.

Q. What is an IP address and what are its two types?  

Answer: An IP address is a numerical label assigned to network devices to uniquely identify them. There are two types of IP addresses: Internet Protocol Version 4 (IPv4) and Internet Protocol Version 6 (IPv6).

Q. Why is an IP address considered a unique identifier of a computer in a computer network?  

Answer: IP addresses can be considered unique identifiers of a computer in a computer network because each computer must have a unique IP address to successfully connect to the network and transfer data.

Q. What is a DHCP server and what is its role in a computer network?  

Answer: A DHCP (Dynamic Host Configuration Protocol) server is a server that maintains a pool of IP addresses in a network. Based on a request, it assigns an IP address from the pool to a computer, overcoming the problem of IP conflict in the network.

Q. What is a MAC address and why is it considered a unique identifier in a computer network?  

Answer: A MAC address (Media Access Control address) is a unique identifier assigned to a Network Interface Controller (NIC). It is considered a unique identifier in a computer network because it is assigned by hardware manufacturers and cannot be changed by a user.

Q. How do different hardware manufacturers maintain the uniqueness of MAC addresses?  

Answer: The MAC address is composed of twelve hexadecimal digits. The first six hexadecimal digits are called OUI (Organizational Unique Identifier). A globally recognized committee, the IEEE Registration Authority Committee, assigns unique OUIs to hardware manufacturers to use as a prefix of MAC addresses. The uniqueness of the remaining six hexadecimal digits is maintained by each manufacturer individually, ensuring that MAC addresses are globally unique.

Q. What is a Network Interface Card (NIC) and what are its other names?  

Answer: A Network Interface Card (NIC) is a hardware component used to connect a computer to a computer network. Without a NIC, a computer cannot be connected to a network. NICs are also called network adapters or LAN adapters.

Q. What are the differences between wired and wireless NICs, and between external and internal NICs?  

Answer: Wired NICs communicate with a wired network, while wireless NICs use an antenna to provide wireless reception and utilize Wi-Fi or other wireless technology as a communication medium. Based on the installation type, a NIC can be either external or internal. External NICs are normally connected using the USB port, while internal NICs are installed inside the CPU on the motherboard slot.

Q. What is the purpose of a hub in a computer network and how does it differ from a switch?  

Answer: A hub is a networking device that connects other computer networking devices together and can act as a repeater to amplify signals that deteriorate after traveling long distances over connecting cables. Unlike switches, hubs do not perform any filtering or addressing with the incoming data; instead, they send all incoming data to all other connected devices.

Q. How does a switch operate and how does it differ from a hub?  

Answer: A switch is a multiport device that is more intelligent than a hub. It maintains routing information about other network devices in the internal network. A switch can read the destination address of incoming data and, with the help of routing information, transmit incoming data to the appropriate destination.

Q. What is the purpose of a router in a computer network and how does it differ from a hub or a switch?  

Answer: A router is a network device used to interconnect two or more heterogeneous computer networks. It can be considered as a small, dedicated special-purpose computer with multiple input and output network interfaces. A router maintains a chart of network IDs and output ports, reads the destination address of incoming data, and transmits it to its destination by following a path through many interconnected networking devices. Unlike hubs or switches, routers store information about the networks in which they are connected and can be used to divide a computer network into many subnetworks.

Q. What is the purpose of an access point in a computer network and what is an SSID?  

Answer: An access point is a network device that creates a wireless network. It allows computers or other devices with a wireless network interface card to connect to the wireless network. The Service Set Identifier (SSID) is a sequence of characters that refers to a wireless local area network. To connect to a wireless network created by an Access Point, the user needs to know the Access Point’s SSID.

Q. What is a network protocol and why is it essential for communication between computers?  

Answer: A network protocol is a set of well-established rules that determine how two computers communicate or transfer data between them. Network protocols make it possible for network devices to communicate with each other because of predetermined rules built into devices’ software and hardware.

Q. Explain the roles of TCP, IP, POP, SMTP, HTTP, and HTTPS protocols in computer networks.  

Answer:

• TCP (Transmission Control Protocol) is a communication protocol used for establishing communication between computers over a network. It divides data into packets, sends them to the destination, and reassembles them at the destination.
• IP (Internet Protocol) is designed for addressing packets and delivering them from a source host to a destination host based on the IP address.
• POP (Post Office Protocol) is designed for receiving incoming emails.
• SMTP (Simple Mail Transfer Protocol) is designed for sending outgoing emails.
• HTTP (Hypertext Transfer Protocol) is the foundation of the World Wide Web, used for fetching web resources such as HTML documents or other web pages.
• HTTPS (Hypertext Transfer Protocol Secure) is a combination of HTTP with added security features, providing encrypted communication between a client and a server.

Q. What is the FTP protocol and what are its limitations?  

Answer: The FTP (File Transfer Protocol) is a standard internet protocol used for transmitting files from one computer to another over a network. The main disadvantage of the FTP protocol is that it does not encrypt the username, password, and data when logging in to the server and during data transfer.

Q. What are SFTP and FTPS protocols, and why were they developed?  

Answer: SFTP and FTPS are both file transfer protocols that use encryption, providing secure methods to transfer files. They were developed to overcome the disadvantages of the FTP protocol, which does not encrypt the username, password, and data during data transfer.

Q. List some examples of third-party client software used for file transfer.  

Answer: Examples of third-party client software used for file transfer include FileZilla Client, FTP Voyager, WinSCP, and Core FTP.

33. Explain the purpose of the following networking commands: ping, ipconfig, hostname, and arp.  

Answer:

• ping: This command is used to verify the connectivity between two computers.
• ipconfig: The ipconfig command is used to determine your computer’s networking information, such as the IP address and the address of its default gateway.
• hostname: This command displays the hostname or computer name of a computer.
• arp: Corresponds to the Address Resolution Protocol (ARP), which maps IP addresses to MAC addresses. The arp command displays the list of IP addresses and their corresponding MAC addresses.