Networking Interview Question and Answer

1. What is a network?

Ans. A network consists of two or more separate devices linked together such that they can communicate. Networking facilitates data communication between computers and peripherals, and it is done through wired cabling or wireless links. Networks can be classified according to different criteria such as scope, type of connection, functional relationship, topology, or function, among others.

2. What are the different types of networks?

Ans. Considering the size or span of a network, we can classify them as follows:

• PAN (Personal Area Network) – PAN is made up of devices used by a single person. It has a range of a few meters.
• WPAN (Wireless Personal Area Network) – It is a PAN network that uses wireless technologies as a medium.
• LAN (Local Area Network) – LAN is a network whose range is limited to a relatively small area, such as a room, a building, an airplane, etc.
• WLAN (Wireless Local Area Network) – WLAN is a LAN network that uses wireless means of communication. It is a widely used configuration due to its scalability and because it does not require the installation of cables.
• CAN (Campus Area Network) – A network of high-speed devices that connects LANs in a limited geographical area, such as a university campus, a military base, etc.
• MAN (Metropolitan Area Network) or metropolitan area network – It is a high-speed (broadband) network providing coverage in a larger geographic area than a campus, but still limited.
• WAN (Wide Area Network) – WAN extends over a large geographical area using unusual means of communication, such as satellites, interoceanic cables, fiber optics, etc. Use public media.
• VLAN – It is a type of logical or virtual LAN, mounted on a physical network, in order to increase security and performance. In special cases, thanks to the 802.11 protocol (also called in), it is possible to mount virtual networks on WAN networks. It is important not to confuse this implementation with VPN technology.

3. What is Network Cabling?

Ans. A cable is a cord that is made up of different conductors, which are insulated from each other. This cord is usually protected by a wrap for better strength and flexibility. Network cables can connect two computers or computer systems directly.

To choose a network cable, several aspects must be taken into account, such as –

• The distance that must be covered with that cable 
• The maximum data transmission speed  
• The coating of the cable  
• The type of network to be created
• The type of braiding, shielding, and/or sheath 

4. What are the different types of network cables used in networking?

Ans. The different types of cables used in networks are – 

• Unshielded Twisted Pair (UTP) Cable
• Shielded Twisted Pair (STP) Cable
• Coaxial Cable
• Fiber Optic Cable
• Cable Installation Guides
• Wireless LANs
• Unshielded Twisted Pair (UTP) Cable

5. What is a ‘subnet’?

Ans. A ‘subnet’ is a generic term for a section of an extensive network, usually separated by a bridge or a router. It also works for the network’s broadcast domains, manages traffic flow, and helps increasing network performance.

Uses of the subnet in networking:

• Relieving network congestion
• Reallocating IP addresses
• Improving network security

6. What is DNS?

Ans. The Domain Name System (DNS) is a central part of the internet, providing a way to match names (a website you’re seeking) to numbers (the address for the website). Anything connected to the internet – laptops, tablets, mobile phones, and websites – has an Internet Protocol (IP) address made up of numbers.

7. Differentiate between ‘forward lookup’ and ‘reverse lookup’ in DNS?

Ans. The major differences between a forward lookup and reverse lookup in DNS are –

8. What is Network Topology?

Ans. This is an important networking interview question. Network topology is the physical or logical arrangement in which the devices or nodes of a network (e.g. computers, printers, servers, hubs, switches, routers, etc.) are interconnected with each other over a communication medium. It consists of two parts – the physical topology, which is the actual arrangement of the cables (the media), and the logical topology, which defines how the hosts access the media.

Types of network topologies –

Bus – In the bus network topology, each workstation is connected to a main cable called a bus. Therefore, in effect, each workstation is directly connected to every other workstation on the network.

Bus network topology

Star – In the star network topology, there is a central computer or server to which all workstations are directly connected. Each workstation is indirectly connected to each other through the central computer.

Star network topology

Ring – In the ring network topology, the workstations are connected in a closed-loop configuration. Adjacent workstation pairs are directly connected. Other pairs of workstations are indirectly connected, passing data through one or more intermediate nodes.

Ring network topology

Mesh – Mesh network topology has two forms – full and partial mesh. In the full mesh topology, each workstation is directly connected to each other. In the partial mesh topology, some workstations are connected to all the others, and some are connected only to the other nodes with which they exchange more data.

Fully Connected Mesh 

Partial Mesh Network Topology

Tree – The tree network topology uses two or more star networks connected to each other. The central computers in star networks are connected to the main bus. Thus, a tree network is a bus network of star networks.

Tree Network Topology

Signal – Signal or Logical topology refers to the nature of the paths that signals follow from node to node. In many cases, the logical topology is the same as the physical topology. But it’s not always like this. For example, some networks are physically arranged in a star configuration, but they function logically as bus or ring networks.

9. What are ‘client’ and ‘server’ in a network?

Ans. Clients and servers are separate logical entities that work together over a network to accomplish a task.

A client application is the element of communication that requests or requests a network service, for example, accessing a web page, or downloading a file, or sending an email.

A server application is the element of communication that responds to customer requests, providing the required service, that is, sending the web page or the requested file or email.

The client-server model is used by computer applications such as email, the worldwide web, and network printing.

10. What is a ‘frame relay’ and in which layer does it operate?

Ans. Frame Relay is a data link layer digital packet-switched network protocol technology designed to connect local area networks (LANs) and transfer data over wide area networks (WANs). Frame Relay shares some of the same underlying technology as X.25.

It is based on the older X.25 packet-switching technology that was designed to transmit analog data as voice conversations. Unlike X.25, which was designed for analog signals, Frame Relay is a fast packet technology, which means that the protocol does not attempt to correct errors. It is often used to connect LANs with main backbones, as well as in public wide area networks and in private network environments with leased T-1 lines. It requires a dedicated connection during the transmission period and is not ideal for voice or video, which require a constant stream of transmissions.

11. What are the different features of Frame Relay?

Ans. The different features of Frame Relay are:

• Frame Relay is a connectionless service, which means that every data packet that passes over the network contains address information
• Frame Relay is a service that is provided with a variety of speeds from 56 Kbs to 25 Mbs. Although the speeds most used for the service are currently 56 Kbs and 1,544 Mbs
• The frames are of variable length and go up to 4,096 bytes
• Frame Relay is considered a broadband ISDN service
• It operates at high speed (1,544 Mbps to 44,376 Mbps).
• It operates only on the physical and data link layers. Therefore, it can be easily used on the Internet.
• It has a large frame size of 9000 bytes. Therefore, it can accommodate all local area network frame sizes.
• Frame Relay can only detect errors (at the data link layer). But there is no flow control or error control. It operates in the data link layer.

12. How does a Frame Relay Work?

Ans. Frame Relay supports the multiplexing of traffic from multiple connections over a shared physical link. It uses hardware components that include router frames, bridges, and switches to pack data into individual frame relay messages. Each connection uses a 10-bit Data Link Connection Identifier (DLCI) for unique channel addressing. There are two types of connections:

• Permanent Virtual Circuits (PVCs) for persistent connections are intended to be maintained for long periods even if data is not actively transferred.
• Switched Virtual Circuits (SVCs) for temporary connections that last only one session.

Frame Relay then places the data in a variable-size unit called a frame and leaves any necessary error correction (data retransmission) until the endpoints, speeding up the overall transmission of data.

Frame Relay

13. What is a MAC address?

Ans. A MAC (Media Access Control) address is the unique 48-bit hardware address of a LAN card, usually stored in the ROM of the network adapter card.

The MAC address is a unique identifier that manufacturers assign to a network card or device. It is also known as a physical address represented by hexadecimal digits. Each MAC address is unique worldwide and, in theory, they are fixed for each device.

Each MAC address includes six pairs of numbers. The first three pairs help to identify the manufacturer and the next three to the specific model. It is important to bear in mind that a computer may have a variety of hardware to connect to networks; thus, it is common to have a MAC address for Ethernet, one for Wi-Fi, and another for Bluetooth.

14. What is ‘beaconing’?

Ans. Beaconing is the process that allows a network to self-repair network problems.

15. Differentiate between ‘attenuation’, ‘distortion’, and ‘noise’.

Ans. When a signal travels through a medium, it loses some of its energy due to the resistance of the medium. This loss of energy is called attenuation.

When a signal travels through a medium from one point to another, it may change the form or shape of the signal. This is known as distortion.

Noise is unwanted electrical or electromagnetic energy that degrades the quality of signals and data.

16. What is an IP address?

Ans. An Internet Protocol address (IP address) is a numerical unique address of a device in a network. IP is a datagram-oriented connectionless protocol, therefore each packet must contain a header with the source IP address, the destination IP address, and other data in order to be delivered successfully.

There are two types of IPs –

Private IP Address – A private IP address is a set of numbers that are assigned to each computer or system, connected to a private network. An example of a private IP address is your mobile phone or your home router which have a default local address.

Public IP Address – Public IP addresses are global addresses, visible to anyone browsing the Internet. A user just needs an internet connection to connect to such devices.

17. How to find the IP address of a website?

Ans. Finding the IP address of a website or a domain is not a tricky task and involves the below steps –

• Press the “Start” button on your computer
• Type in the program and file browser “cdm”
• Hit “Enter”
• The MS-DOS console will open, where you must type “nslookup google.com”. Instead of “google.com”, you must write the domain name of the page you want to consult
• Next, you will be able to see the IP address

18. What is ‘bandwidth’?

Ans. The limited range of frequencies of signals that a line can carry is called the bandwidth. Bandwidth is often confused with Internet speed when it is actually the volume of information that can be sent over a connection in a measured amount of time, calculated in megabits per second (Mbps).

Logically the bandwidth of our network will be decisive for its quality and speed. The more bandwidth we have, the better, since the faster we can transfer data.

19. What are ‘firewalls’?

Ans. A firewall is a network security system, responsible to manage network traffic. It uses a set of security rules to prevent remote access and content filtering. Firewalls are used to protect the systems or networks from viruses, worms, malware, etc. Firewalls are usually of two types –

Physical – A physical firewall or hardware firewall is a physical device, sits between the external network and the server. They analyze incoming traffic and filter out any threats to the device. Widely used in institutions and large companies. 

Logical – A logical or software firewall can exist anywhere on the subnet and protects hosts anywhere on the subnet without rewiring. They only protect the computer on which they are installed, and in many cases, they are integrated into the operating system itself.

20. How does a firewall work?

Ans. This is a popularly asked networking interview question. The firewall ‘listens’ for what information packets are trying to leave or enter the computer system. Blocking can be done based on various criteria, such as the IP to which they are destined, the type of port used to send them, or the application of origin.

One of the most complex aspects of using firewalls lies in their configuration, in deciding what types of connections are blocked and which ones are not.  

21. What are the major types of networks?

Ans. Following are the major types of networks:

• Server-based network
• Peer-to-peer network

22. What are the important topologies for networks?

Ans. There are three essential topologies – Star, Bus, and Ring.

23. Differentiate between static IP addressing and dynamic IP addressing.

Ans. In a static IP address, a computer (or another device) is always configured to use the same IP address, whereas, in a dynamic IP address, the IP address can change periodically and is managed by a centralized network service.

24.  What are the different ways to exchange data?

Ans. Following are the different ways to exchange data:

• Simplex
• Half-duplex
• Full-duplex

25. What are routers?

Ans. Routers connect two or more network segments. These intelligent network devices store information in their routing tables such as paths, hops, and bottlenecks. They determine the most accurate data transfer paths and operate in Open Systems Interconnection (OSI) Network Layer.

The roles of a router are –

• inter-network communication
• Best path selection
• Packet forwarding
• Packet filtering

26. What are the criteria for the best path selection of a router?

Ans. The following parameters define the path selection:

• Longest prefix match
• Minimum AD (administrative distance)
• Lowest metric value

27. Explain what is a source route?

Ans. The source route is defined as a sequence of IP addresses that are used to identify the route of a datagram. You can also involve the source route in the IP datagram header.

28. What is the difference between ‘standard’ and ‘extended’ ACL (access control list)?

Ans. Standard ACLs are source-based, whereas extended ACLs are source- and destination-based.

29. What is data encapsulation?

Ans. Data encapsulation is the process of breaking down information into smaller, manageable chunks before their transmission across the network.

30. What is RAS?

Ans. RAS (Remote Access Services) refers to any combination of hardware and software to enable remote access to tools or information that typically reside on a network of IT devices.

31. Mention the different network protocols that are supported by Windows RRAS services?

Ans. Following are the three main network protocols supported by Windows RRAS services:

• NetBEUI
• TCP/IP
• IPX

32. What are the perquisites to configure a server?

Ans. Perquisites to configure a server are:

• LAN card should be connected
• Root (partition on which window is installed) should be in NTFS format.
• A server should be configured with a static IP address.

33. How can you secure a computer network?

Ans. There are several ways to achieve this.

• Install a reliable and updated antivirus program across the network
• Ensure firewalls are setup and configured properly
• Monitor firewall performance
• User authentication
• Update passwords regularly, every quarter
• Create a virtual private network (VPN)

34. Mention the uses of the Hamming code?

Ans. Following are some of the common applications of using Hemming code:

• Modems
• Satellites
• Plasma CAM
• Shielding wire
• Embedded Processor
• Computer Memory
• Open connectors

35. What are proxy servers and how do they protect computer networks?

Ans. Proxy servers prevent external users from identifying the IP addresses of an internal network. They make a network virtually invisible to external users, who cannot identify the physical location of a network without knowledge of the correct IP address.

36. What are Nodes and Links?

Ans. Nodes – Devices or data points on a more extensive network are known as nodes. They are individual parts of a larger data structure and contain data. They also link other nodes.

Links- A link is the physical and logical network component for interconnecting hosts or nodes in a network. It is a physical communication medium such as a coaxial cable or optical fiber.

37. What is SLIP?

Ans. SLIP or Serial Line Interface Protocol was developed during the early UNIX days and it is used for remote access.

SLIP does not provide error detection as it relies on higher-layer protocols for it. Therefore, SLIP alone is not successful on an error-prone dial-up connection. However, it is still useful to test the operating system’s response capabilities under load (looking at ping flood statistics).

38. What is TCP/IP?

Ans. TCP/IP is the short form of the Transmission Control Protocol / Internet Protocol. It is a set of protocol layers designed to facilitate data exchange on heterogeneous networks.

39. How many layers does TCP/IP Model have?

Ans. TCP/IP Model has four layers: 

40. Explain the different layers in the OSI model? 

Ans. It is one of the most commonly asked networking interview questions. The OSI (Open Systems Interconnection) Model consists of seven layers:

41. A gateway works in which layer of the OSI model?

Ans. Transport layer.

42. Explain why the standard OSI model is known as 802.xx?

Ans. The OSI model was introduced in February 1980. In 802.XX, ‘80’ is named for the year 1980, and ‘2’ is named as the month of February.

43. What common software problems lead to network defects?

Ans. It can be any or a combination of –

• Application conflicts
• Client-server problems
• Configuration error
• Protocol mismatch
• Security issues
• User policy & rights issues

44. Why is encryption on a network necessary?

Ans. Encryption is the process of changing data from its original readable format to an unreadable format, thus ensuring network security. It requires the user to use a secret key or password to decrypt the data.

Encryption is not only useful for communications, but also in any case where you want to protect sensitive information. Thus, it is possible to encrypt the information contained in disks, folders or even individual files, to prevent unauthorized access. Then, in addition to the benefit of protecting the privacy of users, data encryption prevents other types of attacks such as identity theft, or bank fraud, in addition to providing a protection mechanism against the theft or loss of devices with sensitive information.

45. What are the types of errors?

Ans. There are two categories of errors –

• Single-bit error – one-bit error per data unit
• Burst error – Two or more bits errors per data unit

46. What is a client-server model?

Ans. The client-server model or architecture is a communication framework for network processes. This framework is distributed among service requestors, clients, and service providers and offers them transparent access to applications, data, computing services or any other resource of the workgroup and/or across the organization, on multiple platforms.  

Client-Server Functions

• User interface management
• Capture and validation of input data
• Generation of queries and reports on databases 
• Management of shared peripherals
• Control of concurrent access to shared databases
• Create communications links with other local or wide area networks

47. What is TELNET?

Ans. TELNET is a client-service protocol on the internet or local area network, allowing a user to log on to a remote device and have access to it. Technically, it is a bidirectional interactive text-oriented communication facility, which uses a virtual terminal connection.

48. What is RIP?

Ans. It is the abbreviation for Routing Information Protocol. It is a simple protocol that exchanges information between the routers.

49. What is half-duplex?

Ans. It is the mode of communication between two devices. Here the data flows bi-directionally but simultaneously. A perfect example of a half-duplex is a walkie-talkie.

50. What is a full-duplex?

Ans. It is a mode of communication between two devices and the data flow is bi-directional too, but the flow is simultaneous. Example – telephone.

51. What is net stat?

Ans. Net stat is a command-line utility program that provides information about the current Transmission Control Protocol /Internet Protocol (TCP/IP) settings of a connection.

52. What is a peer-peer process?

Ans. The processes on each machine that communicate at a given layer are called the peer-peer process.

53. What is anonymous FTP?

Ans. With the help of an anonymous FTP, users can be granted access to files in public servers. Users can log in as anonymous guests, thus the name.

54. What is NAT?

Ans. It stands for Network Address Translation and is a protocol that allows a network device, usually a firewall, to assign a public address to a computer/s inside a private network.

55. Mention a few examples of private network addresses.

Ans. Few examples of private network addresses are:

10.0.0.0 With a subnet cover of 255.0.0.0172.16.0.0 with subnet cover of 255.240.0.0192.168.0.0 with subnet cover of 255.255.0.0.

56. Can you tell me the main elements of a protocol?

Ans. This is among the very commonly asked networking interview questions. Your reply should be –

There are three main elements of a protocol –

1. Syntax: It refers to the structure or format of the data and their order of presentation.
2. Semantics: It specifies the meaning of each section of bits.
3. Timing: Timing refers to two characteristics, which include the timing of data sending and the speed of data sending.

57. What is NIC?

Ans. NIC is the abbreviation for Network Interface Card. It is a peripheral card with electronic circuitry. It is attached to a PC and connects it to a network. NIC has its own MAC address and this identifies a PC on the network.

58. What is the difference between Communication and Transmission?

Ans. Transmission – A process of sending and receiving data between source and destination, in only one way. It is regarded as the physical movement of data.

Communication – A process of sending and receiving data between source and destination, in both ways.

59. Explain NAT in networking.

Ans. Network Address Translation (NAT) is a protocol used to convert the IP address of the computer network into a local network to a single IP address. It takes all your local network devices and provides a single IP address to share a single connection to the internet. NAT is used router, computer, and firewall in a local network.

60. Explain NOS.

Ans. Short form for Network Operating System. Specialized software that provides connectivity to a computer such that it can communicate with other computers and devices on a network.

61. What is IDEA?

Ans. IDEA is the abbreviation for International Data Encryption Algorithm. It is the replacement for the Data Encryption Standard (DES).

62. What is ASCII?

Ans. American Standard Code for Information Interchange.

63. What is B router?

Ans. B router is a device that functions as both a bridge and a router. It forwards data within the networks and also routes data to individual systems in a network.

64. Mention the maximum length of the Thinnet cable?

Ans. The maximum length of the Thinnet cable is 185 meters.

65. Name the cable which uses the RJ11 connector?

Ans. Telephone cables use the RJ11 connector.

66. How would you differentiate between Firewall and Antivirus?

Ans. Both are security applications used in networking.

A firewall prevents unauthorized access in private networks as intranets. However, it does not protect against viruses, spyware, or adware.

An antivirus is a software that protects a computer from any malicious software, virus, spyware, or adware.

67. How will you recover data from a Virus-infected system?

Ans. We will install an OS and updated antivirus in a system that is free of any viruses, and then connect the hard drive of the infected system as a secondary drive. The hard drive will then be scanned and cleaned. Data can now be copied into the system.

68. What is ipconfig?

Ans. An acronym for Internet Protocol Configuration, Ipconfig is used on Microsoft Windows to view and configure the network interface. It displays all TCP/IP network summary information available on a network and helps to modify the DHCP protocol and DNS settings.

69. What is ifconfig?

Ans. It is an acronym for Interface Configuration and is used on Linux, Mac, and UNIX operating systems. ifconfig configures and controls the TCP/IP network interface parameters from Command Line Interface while allowing the user to check the IP addresses of these network interfaces.

70. What is the semantic gap?

Ans. A semantic gap is a difference between high-level programming sets in various computer languages and the simple computing instructions used by microprocessors.

71. What is the difference between a Domain and a Workgroup?

Ans. This is an important networking interview question that you must prepare for your interview. The main difference between a Domain and a Workgroup is where the computer networks belong to do. If it is a home network, then computers will be a part of a workgroup, and if it’s a workplace network, then the computers will be a part of a domain. 

Below are some of the major differences between a Domain and a Workgroup:

72. What Is NVT?

Ans. NVT stands for Network Virtual Terminal and is a representation of a primary terminal. This virtual terminal helps you to start a telnet session.

73. What Is BGP?

Ans. BGP or Border Gateway Protocol is a protocol used to transfer data and information between different host gateways or autonomous systems.

74. What is Round Trip Time?

Ans. Round Trip Time or RTT is the time taken to send a message from one end of a network to the other and back.

75. What are 127.0.0.1 and localhost?

Ans. Localhost is the standard hostname given to the machine, and it is represented by the IP address 127.0.0.1. Therefore, we can say that 127.0.0.1 and localhost are the same thing.

76. Which are the most typical functional units of the client/server applications?

Ans. The most typical functional units of the client/server applications are –

• Presentation logic or user interface (e.g., ATMs)
• Business logic (e.g., Account balance inquiry)
• Data (e.g., Bank account records)

77. What are the Triggers?

Ans. Triggers are event-driven specialized procedures and are managed by database management systems. It is capable of performing complex actions and uses procedural languages full throttle.

78. What is a Gateway?

Ans. A gateway is a hardware device that is connected to two or more networks. It may be a router, firewall, server, or any other similar device, and is capable of regulating traffic in the network.

79. Is there a difference between a gateway and a router?

Ans. A gateway sends the data between two dissimilar networks, while a router sends the data between two similar networks.

80. What is a VPN (Virtual Private Network)? What are the advantages of using a VPN Connection? 

Ans. A VPN or Virtual Private Network is an encrypted connection (secure tunnel) built on the internet from a device to a network. It helps in the creation of a protected network between different networks using the internet (public network), ensuring that sensitive data is safely transmitted. This makes it difficult for third parties to gain unauthorized access, track your activities online, or steal data. By using the VPN, a client can connect to the organization’s network remotely.  

Some of the advantages of using VPN Connection are: 

1. Remote Access
2. Protected File Sharing
3. Anonymity
4. Enhanced Security
5. Improved Performance
6. Anonymity 
7. Network Scalability
8. Prevents Data Throttling

81. Explain the different types of VPN. 

Ans. There are two types of VPNs: 

1. Remote Access Virtual Private Network:

A Remote Access VPN securely connects a device (endpoints like laptops, tablets, or smartphones) outside the corporate office. It allows a client to associate with a private network and access every one of its resources and services remotely. The connection between the private network and the user happens securely through the Internet. It is a low-cost solution and is helpful for both business and home users.

1. Site-to-Site or Router-to-Router Virtual Private Network: 

This VPN is mostly used in large organizations with branches in different locations to connect the network of one office to another in different locations. It has two sub-categories:

• Intranet VPN: Intranet VPN allows several offices of the same company to connect using the Site-to-Site VPN type. It is commonly used for connecting remote offices in different geographical locations using shared infrastructure (internet connectivity and servers) with the same accessibility policies as a private WAN (wide area network).
• Extranet VPN: Extranet VPN allows companies to use Site-to-site VPN type to connect to the office of another company. It uses shared infrastructure over an intranet, suppliers, customers, partners, etc., and connects them using dedicated connections. 

82. What is EGP? What are its advantages?

Ans. EGP stands for Exterior Gateway Protocol. It is used to exchange net-reachability information between Internet gateways within the same or different autonomous systems. EGP is the protocol of the routers. It is used to identify the set of networks that you will able to reach within or via each independent system.

83. Explain 10Base-T.

Ans. 10Base-T specifies data transfer rate, i.e., 10Mbps. Here the usage of the term ‘Base’ defines ‘Baseband’ and not ‘Broadband’. T denotes the type of cable, which is a twisted pair.

84. Name the user support layers.

Ans. There are three types of user support layers –

• Session Layer
• Presentation Layer and
• Application Layer

85. What is Piggy Backing?

Ans. It is the process of gaining access to a restricted communications channel by using an already established session by another user. This technique is known to improve the efficiency of the bidirectional protocols.

86. What is asynchronous transmission?

Ans. It is a serial mode of transmission. It is the process of data transmission, where every character is a self-contained unit. Each character in asynchronous transmission has its start and stop bits, along with an uneven interval between them.

87. What is synchronous transmission?

Ans. Synchronous transmission refers to continuous data streaming in the form of signals, accompanied by regular timing signals. These signals are generated by the external clocking mechanism and ensure that senders and receivers are in synchrony.

88. What are the different types of transmission media?

Ans. Transmission media has two broad types –

• Guided media (wired)
• Unguided media (wireless)

89. What is Process Sigma?

Ans. Process Sigma measures the frequency of a task that is performed without any error. It is expressed as a number of standard deviations on a normal distribution.

90. What is FMEA?

Ans. Failure Mode Effect and Analysis or FMEA is a qualitative and systematic tool to identify potential failure modes in a system, the reasons, and their effects.

91. What is the backbone network?

Ans. It refers to a centralized infrastructure for distributing different routes and data to various networks. Backbone networks connect LANs and WANs and also handles the management of bandwidth and multiple channels.

92. What is OSPF?

Ans. OSPF is an abbreviation for Open Shortest Path First. It is a routing protocol that uses a link-state routing (LSR) algorithm to find out the best possible path for data exchange.

93. What is the range of addresses in the classes of internet addresses?

Ans. Following are the five different ranges of addresses in the classes of the internet:

• Class A: 0.0.0.0 – 127.255.255.255
• Class B: 128.0.0.0 – 191.255.255.255
• Class C: 192.0.0.0 – 223.255.255.255
• Class D: 224.0.0.0 – 239.255.255.255
• Class E: 240.0.0.0 – 247.255.255.255

94. What are Datalink Protocols?

Ans. Datalink protocols are defined as the sets of requirements used to implement the data link layer. There are the following categories of Data Link protocols:

• Synchronous Protocols
• Asynchronous Protocols
• Bit Oriented protocols
• Character Oriented Protocols

95. What are the functions of a Network Layer?

Ans. The Network Layer or OSI Layer 3 provides services for exchanging individual sections of data over the network between identified end devices. To perform this end-to-end transport Layer 3 uses four basic processes:

• Addressing
• Encapsulation
• Routing
• Decapsulation

96. Name the access method used in the 1000BaseTX network.

Ans. CSMA/CD access method is used in the 1000BaseTX network.

97. Mention the different types of links used to build a computer network.

Ans. Following are the different types of links used to build a computer network:

• Cables
• Wireless Links
• Last-Mile Links
• Leased Lines

98. Mention the types of wires used for data transmission in UTP cable.

Ans. There are four types of wires used for data transmission in UTP cable, which is wire 1, 2, 3, and 6. Where wires 1 and 2 are used to transmit the data while wires 3 and 6 are used to receive the data.

99. Can we use RG59 and RG6 cables in a computer network?

Ans. RG59 and RG6 cables are not used in the computer network. These cables are made for the cable TV network.

100. What is 10Base2?

Ans. 10Base2 is defined as part of the IEEE 802.3a standard, specifies data transmission speeds of 10Mbps and a total segment length of 185 meters using RG-58 coaxial cable. The 10Base2 standard specifies a physical bus topology and uses BNC connectors with 50-ohm terminators at each end of the cable. One of the physical ends of each segment must be grounded.

101. Name the cable used in the 10BaseFL network.

Ans. Fiber optical cable is the cable used in the 10BaseFL network.

102. Why is IP protocol deliberated as a connectionless protocol?

Ans. An IP protocol is deliberated as a connectionless protocol because it does not build up a connection before sending data to the endpoint.

103. How many network segments can be populated in 10Base2?

Ans. 10Base2 networks allow a maximum of five segments with only three of those segments populated. Each of the three populated segments can have a maximum of 30 nodes attached.

104. What is the point-to-point protocol?

Ans. A communications protocol is used to connect computers to remote networking services, including Internet service providers.

105. What is NIC?

Ans. The NIC stands for the network interface controller. NIC is a device or module that controls and configures the interface of a processor system to a network or other interconnection. There are many different types of interfaces in electronic systems. NICs generally configure, maintain the current state, handle faults, and provide algorithm implementation to successfully transfer data to and from the interface.

106. Mention any five applications that use TCP port.

Ans. Following are the five application that uses TCP port:

• FTP
• POP
• SSH
• SMTP
• Telnet

107. What is the 5-4-3 rule? In which architecture it is used?

Ans. In the 5-4-3 rule, there is a maximum of five segments in a network that are connected with four repeaters. It is used in 10Base2 and 10Base5 Ethernet architectures. In this rule, only three segments can be populated with nodes.

108. Name the measurement unit used to measure the transmission speed of Ethernet?

Ans. Mbps is the measurement unit used to measure the transmission speed of Ethernet.

109. Name the switching method used to explore the destination Mac address.

Ans. The switching method that is used to explore the destination Mac address is Cut Through.

110. Mention the use of DDR on Cisco routers.

Ans. DDR stands for dial-on-demand routing used to generate and close a circuit-switched session. It provides on-demand routing to the low volume and periodic traffic.

111. Mention the number of access lists required per interface.

Ans. One access list can be used per interface and per protocol.

112. What is the possible way to convert the user data from DTE to the WAN Service Form?

Ans. To convert the user data from DTE to WAN Service Form, we can use the Modem, CSU/DSU, and TA/NT1.

113. Name the types of WAN services obtained by Cisco routers.

Ans. WAN services obtained by Cisco routers are switched services where protocols are used to connect end to end devices and Interface front end.

114. Name the various technologies involved in building WAN links?

Ans. Various technologies involved in building WAN links are:

• Digital connections – using digital-grade telephone lines
• Analog connections – using conventional telephone lines
• Switched connections – using different sets of links between the sender and receiver to move data.

115. Explain the Sliding Window in Agile?

Ans. In the Sliding Window, the sender and receiver are required to deal with the manageable sequence numbers. This abstract concept defines the range of sequence numbers with the concern of sender and receiver.

116. What standard color sequences are used for a straight-through cable?

Ans. Standard color sequences used for a straight-through cable are Orange/white, orange, green/white, green, blue/white, blue, brown/white, brown.

117. What is a Network Interface Card?

Ans. Network Interface Card is a connecting device used to interlink computers with the network. These cards are of two types:

• Internal network cards
• External network cards

118. What is SMTP?

Ans. Simple Mail Transfer Protocol (SMTP) is a protocol used to move all internal mail across different networks. It works with Mail Transfer Agent (MTA) and provides the mail transmission on the TCP/IP protocol stack.

119. Explain the role of the IEEE in computer networking?

Ans. Institute of Electrical and Electronics Engineers (IEEE) is an organization comprised of engineers that manage standards for electrical and electronic devices. It involves networking devices, cablings, network interfaces, and connectors.

120. Name the layers of the TCP IP protocol suite that are involved in a link-layer switch.

Ans. In TCP IP protocol, a link-layer switch is involved with the data-link layer and physical layer.

121. What is MAU?

Ans. Multistation Access Unit (MAU) is a device used to connect multiple network stations in star topology in the form of a ring which is also known as a token ring network.

122. Mention the maximum number of networks and hosts used in classes A, B, and C networks.

Ans. The maximum number of networks and hosts used in class A, B, and C networks are:

• Class A:  126 networks, 16,777,214 hosts.
• Class B: 16,384 networks, 65,534 hosts.
• Class C: 2,097,152 networks, 254 hosts.

123. Differentiate between a ‘bit rate’ and ‘baud rate’.

Ans. A bit rate is the number of bits transmitted during one second, whereas, baud rate refers to the number of signal units per second that are required to represent those bits.

Baud rate = bit rate / N, where N is the no. of bits represented by each signal shift.

124. What is Project 802?

Ans. It is a project started by IEEE to set standards to enable intercommunication between equipment from a variety of manufacturers.

125. What is ICMP?

Ans. ICMP (Internet Control Message Protocol) is a network layer protocol of the TCP/IP suite used by hosts and gateways to send notification of datagram problems back to the sender.

126. What are the differences between TCP and UDP?

Ans. This is an important networking interview question. The differences between TCP and UDP are: 

127. Explain the DHCP Protocol. 

Ans. DHCP stands for Dynamic Host Configuration Protocol. It a standardized network protocol used on Internet Protocol (IP) networks. It is used to auto-configure devices on IP networks enabling them to use the TCP and UDP-based protocols. The DHCP servers automatically assign IP addresses to the network devices which reduces the errors caused by the manual allocation of IP addresses. DHCP is commonly used in networks ranging in size from small home networks to campus networks.