| 1. | When collection of various computers seems a single coherent system to its client, then it is called |
| A. | computer network |
| B. | distributed system |
| C. | networking system |
| D. | mail system |
| Answer» B. distributed system | |
| Explanation: a computer network is defined as a collection of interconnected computers which uses a single technology for connection. | |
| 2. | Two devices are in network if |
| A. | a process in one device is able to exchange information with a process in another device |
| B. | a process is running on both devices |
| C. | pids of the processes running of different devices are same |
| D. | a process is active and another is inactive |
| Answer» A. a process in one device is able to exchange information with a process in another device | |
| Explanation: a computer network, or data network, is a digital telecommunications network which allows nodes to share resources. in computer networks, computing devices exchange data with each other using connections between nodes. the nodes have certain processes which enable them to share a specific type of data using a distinct protocol. | |
| 3. | Which of the following computer networks is built on the top of another network? |
| A. | prior network |
| B. | chief network |
| C. | prime network |
| D. | overlay network |
| Answer» D. overlay network | |
| Explanation: an overlay network is a computer network that is built on top of another network. some examples of an overlay network are virtual private networks (vpn) and peer-to-peer networks (p2p). | |
| 4. | In computer network nodes are |
| A. | the computer that originates the data |
| B. | the computer that routes the data |
| C. | the computer that terminates the data |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: in a computer network, a node can be anything that is capable of sending data or receiving data or even routing the data to its destination. routers, computers and smartphones are some examples of network nodes. | |
| 5. | Communication channel is shared by all the machines on the network in |
| A. | broadcast network |
| B. | unicast network |
| C. | multicast network |
| D. | anycast network |
| Answer» A. broadcast network | |
| Explanation: in a broadcast network, information is sent to all stations in a network whereas in a multicast network the data or information is sent to a group of stations in the network. in unicast network, information is sent to only one specific station. the broadcast address of the network is the last assigned address of the network. | |
| 6. | Bluetooth is an example of |
| A. | personal area network |
| B. | local area network |
| C. | virtual private network |
| D. | wide area network |
| Answer» A. personal area network | |
| Explanation: bluetooth is a wireless technology used to create a wireless personal area network for data transfer up to a distance of 10 meters. it operates on 2.45 ghz frequency band for transmission. | |
| 7. | A is a device that forwards packets between networks by processing the routing information included in the packet. |
| A. | bridge |
| B. | firewall |
| C. | router |
| D. | hub |
| Answer» C. router | |
| Explanation: a router is a networking device that forwards data packets between computer networks. routers perform the traffic directing functions on the internet. they make use of routing protocols like rip to find the cheapest path to the destination. | |
| 8. | A list of protocols used by a system, one protocol per layer, is called |
| A. | protocol architecture |
| B. | protocol stack |
| C. | protocol suite |
| D. | protocol system |
| Answer» B. protocol stack | |
| Explanation: a protocol stack refers to a group of protocols that are running concurrently that are employed for the implementation of network protocol suite. each layer in the network model has to use one specific protocol from the protocol stack. | |
| 9. | Network congestion occurs |
| A. | in case of traffic overloading |
| B. | when a system terminates |
| C. | when connection between two nodes terminates |
| D. | in case of transfer failure |
| Answer» A. in case of traffic overloading | |
| Explanation: network congestion occurs when traffic in the network is more than the network could handle. to avoid network congestion, the network management uses various open-loop and closed-loop congestion control techniques. | |
| 10. | Which of the following networks extends a private network across public networks? |
| A. | local area network |
| B. | virtual private network |
| C. | enterprise private network |
| D. | storage area network |
| Answer» B. virtual private network | |
| Explanation: a virtual private network extends a private network across a public network, and enables users to send and receive data across shared or public networks as if their computing devices were directly connected to the private network.vpn provides enhanced security and online anonymity to users on the internet. it is also used to unblock websites which are unavailable in certain regions. | |
| 11. | Physical or logical arrangement of network is |
| A. | topology |
| B. | routing |
| C. | networking |
| D. | control |
| Answer» A. topology | |
| Explanation: topology in networks is the structure or pattern in which each and every node in the network is connected. there are many topologies in networking like bus, tree, ring, star, mesh, and hybrid topology. there is no particular best topology and a suitable topology can be chosen based on the kind of application of the network . | |
| 12. | Which network topology requires a central controller or hub? |
| A. | star |
| B. | mesh |
| C. | ring |
| D. | bus |
| Answer» A. star | |
| Explanation: in star topology, no computer is connected to another computer directly but all the computers are connected to a central hub. every message sent from a source computer goes through the hub and the hub then forwards the message only to the intended destination computer. | |
| 13. | topology requires a multipoint connection. |
| A. | star |
| B. | mesh |
| C. | ring |
| D. | bus |
| Answer» D. bus | |
| Explanation: in bus topology, there is a single cable to which all the network nodes are connected. so whenever a node tries to | |
| 14. | Data communication system spanning states, countries, or the whole world is |
| A. | lan |
| B. | wan |
| C. | man |
| D. | pan |
| Answer» B. wan | |
| Explanation: wan is the abbreviation for wide area network. this network extends over a large geographical area. wans are used to connect cities, states or even countries. a wireless connection is required to build a wan. the best example of wan is the internet. | |
| 15. | Data communication system within a building or campus is |
| A. | lan |
| B. | wan |
| C. | man |
| D. | pan |
| Answer» A. lan | |
| Explanation: lan is an abbreviation for local area network. this network interconnects computers in a small area such as schools, offices, residence etc. it is the most versatile kind of data communication system where most of the computer network concepts can be visibly used. | |
| 16. | WAN stands for |
| A. | world area network |
| B. | wide area network |
| C. | web area network |
| D. | web access network |
| Answer» B. wide area network | |
| Explanation: wan is the abbreviation for wide area network. this network extends | |
| 17. | In TDM, slots are further divided into |
| A. | seconds |
| B. | frames |
| C. | packets |
| D. | bits |
| Answer» B. frames | |
| Explanation: tdm is the abbreviation for time division multiplexing. it is technique for combining several low rate channels to a single high rate channel. for a certain time slot, the several channels could use the maximum bandwidth. each channel is inactive for a period of time too. some other multiplexing techniques are frequency division multiplexing and phase division multiplexing. | |
| 18. | is the multiplexing technique that shifts each signal to a different carrier frequency. |
| A. | fdm |
| B. | tdm |
| C. | both fdm & tdm |
| D. | pdm |
| Answer» A. fdm | |
| Explanation: fdm is an abbreviation for frequency division multiplexing. this technique is used when the bandwidth of the channel is greater than the combined bandwidth of all the signals which are to be transmitted. the channel is active at all times unless a collision occurs with another channel trying to use the same frequency. some other multiplexing techniques are time division multiplexing and phase division multiplexing. | |
| 19. | What is internet? |
| A. | a single network |
| B. | a vast collection of different networks |
| C. | interconnection of local area networks |
| D. | interconnection of wide area networks |
| Answer» B. a vast collection of different networks | |
| Explanation: internet is nothing but an interconnected computer network providing a variety of communication facilities, consisting of a huge amount of small networks using standardized communication protocols. | |
| 20. | To join the internet, the computer has to be connected to a |
| A. | internet architecture board |
| B. | internet society |
| C. | internet service provider |
| D. | different computer |
| Answer» C. internet service provider | |
| Explanation: the isps (internet service providers) are the main agents through which every computer is connected to the internet. they are licensed to allot public ip addresses to its customers in order to connect them to the internet. | |
| 21. | Internet access by transmitting digital data over the wires of a local telephone network is provided by |
| A. | leased line |
| B. | digital subscriber line |
| C. | digital signal line |
| D. | digital leased line |
| Answer» B. digital subscriber line | |
| Explanation: dsl (digital subscriber line) is the technology designed to use the existing telephone lines to transport high-bandwidth data to service subscribers. dsl was used to allow the early users access to the internet and it provides dedicated, point-to-point, public network access. | |
| 22. | 3 OVERVIEW OF INTERNET |
| A. | internet exchange point |
| B. | subscriber end point |
| C. | isp end point |
| D. | internet end point |
| Answer» A. internet exchange point | |
| Explanation: isps exchange internet traffic between their networks by using internet exchange points. isps and cdns are connected to each other at these physical locations are they help them provide better service to their customers. | |
| 23. | Which of the following protocols is used in the internet? |
| A. | http |
| B. | dhcp |
| C. | dns |
| D. | dns, http and dns |
| Answer» D. dns, http and dns | |
| Explanation: http is used to browse all the websites on the world wide web, dhcp is used to allot ips automatically to the users on the internet, and dns is used to connect the users to the host servers on the internet based on the domain name. | |
| 24. | Internet works on |
| A. | packet switching |
| B. | circuit switching |
| C. | both packet switching and circuit switching |
| D. | data switching |
| Answer» A. packet switching | |
| Explanation: packet switching is the method based on which the internet works. packet switching features delivery of packets of data between devices over a shared network. | |
| 26. | Which protocol assigns IP address to the client connected in the internet? | |
| A. | dhcp | |
| B. | ip | |
| C. | rpc | |
| D. | rsvp | |
| Answer» A. dhcp | ||
| Explanation: dhcp stands for domain host control protocol. it is responsible to remotely assign ip address to the clients connected to the internet. the server that performs this fuction is called the dhcp server. | ||
| 27. | Which one of the following is not used in media access control? |
| A. | ethernet |
| B. | digital subscriber line |
| C. | fiber distributed data interface |
| D. | packet switching |
| Answer» D. packet switching | |
| Explanation: packet switching is not really related to media access control as it just features delivery of packets of data between devices over a shared network. internet is actually based on packet switching. | |
| 28. | Which level is the network layer in the OSI model? |
| A. | third level |
| B. | fourth level |
| C. | second level |
| D. | fifth layer |
| Answer» A. third level | |
| Explanation: the network layer is the third level of the open system interconnection model and the layer that provides data routing paths for network communication. | |
| 29. | Data in network layer is transferred in the form of |
| A. | layers |
| B. | packets |
| C. | bytes |
| D. | bits |
| Answer» B. packets | |
| Explanation: data is transferred in the form of packets via logical network paths in an ordered format controlled by the network layer. | |
| 30. | The network layer contains which hardware device? |
| A. | routers, bridges |
| B. | bridges only |
| C. | bridges and switches |
| D. | routers, bridges and switches |
| Answer» D. routers, bridges and switches | |
| Explanation: this layer contains hardware devices such as routers, bridges, firewalls, and switches, but it actually creates a logical image of the most efficient communication rout and implements it with a physical medium. | |
| 31. | Network layer protocol exits in |
| A. | host |
| B. | switches |
| C. | packets |
| D. | bridges |
| Answer» A. host | |
| Explanation: network layer protocols exits in every host or router. the router examines the header fields of all the ip packets that pass through it. | |
| 32. | What are the common protocols associated with the network layer? |
| A. | address resolution protocol |
| B. | reverse address resolution protocol |
| C. | internet protocol |
| D. | neighbour discovery protocol |
| Answer» C. internet protocol | |
| Explanation: internet protocol and netware ipx/spx are the most common protocols associated with the network layer. | |
| 33. | The network layer responds to request from which layer? |
| A. | transport layer |
| B. | data layer |
| C. | application layer |
| D. | session layer |
| Answer» A. transport layer | |
| Explanation: in osi model, we are having 7 layers in which the network layer responds to request from the layer above it called transport layer. | |
| 34. | The network layer issues request to which layer? |
| A. | transport layer |
| B. | data layer |
| C. | application layer |
| D. | session layer |
| Answer» B. data layer | |
| Explanation: in osi model, we are having 7 layers in which the network layer issues request to the layer below it called data link layer. | |
| 35. | IP is connectionless. |
| A. | true |
| B. | false |
| Answer» A. true | |
| Explanation: ip is connectionless, is that a data packet can travel from a sender to a receiver without the recipient having to send an acknowledgment connection-oriented protocols exits at other, higher layers of the osi model. | |
| 36. | Does network layer in TCP/IP and OSI Model are same. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: the tcp/ip internet layer is in fact only a subset of functionality of the network layer. it describes only one type of network architecture, the internet. | |
| 37. | What are called routers? |
| A. | the devices that operates at session layer |
| B. | the devices that operates at data layer |
| C. | the devices that operates at application layer |
| D. | the devices that operates at network |
| Answer» D. the devices that operates at network | |
| Explanation: the network interconnection devices that operate at the network layer are usually called routes, which at this point should hopefully come as no surprise to you. | |
| 38. | ICMP stands for |
| A. | internet coordinate message protocol |
| B. | internet control message protocol |
| C. | interconnect control message protocol |
| D. | interconnect coordinate message protocol |
| Answer» B. internet control message protocol | |
| Explanation: the internet protocol is the key network layer protocol that implements the tcp/ip protocol suites. since ip is the protocol that provides the mechanism for delivering datagrams, between devices, it is designed to be relatively basic, and to function with few “bell and whistles”. | |
| 39. | Packets will be transferred in how many types? |
| A. | 5 types |
| B. | 4 types |
| C. | 2 types |
| D. | 3 types |
| Answer» D. 3 types | |
| Explanation: routing deals with determining how packet will routed (transferred) from source to destination. it can of three types : 1. static | |
| 40. | DDP stands for |
| A. | datagram delivery protocol |
| B. | device delivery protocol |
| C. | datagram device protocol |
| D. | device datagram protocol |
| Answer» A. datagram delivery protocol | |
| Explanation: datagram delivery protocol is a member of the appletalk networking protocol suite. its main responsibility is for socket to socket delivery of datagram over an appletalk network. | |
| 41. | RIP stands for |
| A. | reduced information protocol |
| B. | routing internet protocol |
| C. | routing information protocol |
| D. | reduced internet protocol |
| Answer» C. routing information protocol | |
| Explanation: the routing information protocol is one of the oldest distance vector routing protocols which employ the hop count as a routing metric. | |
| 42. | The model is 7-layer architecture where each layer is having some specific functionality to perform. |
| A. | tcp/ip |
| B. | cloud |
| C. | osi |
| D. | ois |
| Answer» C. osi | |
| Explanation: the osi model is 7-layer architecture where each layer is having some specific functionality to perform. all these layers work in collaboration for transmitting the data from 1 person to another worldwide. | |
| 43. | The full form of OSI is OSI model is |
| A. | open systems interconnection |
| B. | open software interconnection |
| C. | open systems internet |
| D. | open software internet |
| Answer» A. open systems interconnection | |
| Explanation: the osi model is 7-layer architecture where each layer is having some specific functionality to perform. all these layers work in collaboration for transmitting the data from 1 person to another worldwide. | |
| 44. | Which of the following is not physical layer vulnerability? |
| A. | physical theft of data & hardware |
| B. | physical damage or destruction of data & hardware |
| C. | unauthorized network access |
| D. | keystroke & other input logging |
| Answer» C. unauthorized network access | |
| Explanation: unauthorized network access is | |
| 45. | In layer, vulnerabilities are directly associated with physical access to networks and hardware. |
| A. | physical |
| B. | data-link |
| C. | network |
| D. | application |
| Answer» A. physical | |
| Explanation: in the physical layer, vulnerabilities are directly associated with physical access to networks and hardware such as unauthorised network access, damage or destruction of data & hardware and keystroke & other input logging. | |
| 46. | Loss of power and unauthorized change in the functional unit of hardware comes under problems and issues of the physical layer. |
| A. | true |
| B. | false |
| Answer» A. true | |
| Explanation: loss of power and unauthorized change in the functional unit of hardware comes under problems and issues of the physical layer. other such issues are unauthorised network access, damage or destruction of data & hardware and keystroke & other input logging. | |
| 47. | Which of the following is not a vulnerability of the data-link layer? |
| A. | mac address spoofing |
| B. | vlan circumvention |
| C. | switches may be forced for flooding traffic to all vlan ports |
| D. | overloading of transport-layer mechanisms |
| Answer» D. overloading of transport-layer mechanisms | |
| Explanation: mac address spoofing, vlan circumvention and switches may be | |
| 48. | is data-link layer vulnerability where stations are forced to make direct communication with another station by evading logical controls. |
| A. | vlan attack |
| B. | vlan circumvention |
| C. | vlan compromisation method |
| D. | data-link evading |
| Answer» B. vlan circumvention | |
| Explanation: vlan circumvention is data- link layer vulnerability where stations are forced to make direct communication with another station by evading logical controls implemented using subnets and firewalls. | |
| 49. | may be forced for flooding traffic to all VLAN ports allowing interception of data through any device that is connected to a VLAN. |
| A. | switches |
| B. | routers |
| C. | hubs |
| D. | repeaters |
| Answer» A. switches | |
| Explanation: switches may be forced for flooding traffic to all vlan ports allowing interception of data through any device that are connected to a vlan. it is a vulnerability of data link layer. | |
| 51. | Which of the following is an example of physical layer vulnerability? | |
| A. | mac address spoofing | |
| B. | physical theft of data | |
| C. | route spoofing | |
| D. | weak or non-existent authentication | |
| Answer» B. physical theft of data | ||
| Explanation: physical theft of data is an example of physical layer vulnerability. other such issues are unauthorized network access, damage or destruction of data & hardware and keystroke & other input logging. | ||
| 52. | Which of the following is an example of data-link layer vulnerability? |
| A. | mac address spoofing |
| B. | physical theft of data |
| C. | route spoofing |
| D. | weak or non-existent authentication |
| Answer» A. mac address spoofing | |
| Explanation: mac address spoofing is an example of data-link layer vulnerability. | |
| 53. | Which of the following is an example of network layer vulnerability? |
| A. | mac address spoofing |
| B. | physical theft of data |
| C. | route spoofing |
| D. | weak or non-existent authentication |
| Answer» C. route spoofing | |
| Explanation: route spoofing is an example of network layer vulnerability. other examples of network layer vulnerabilities are ip address spoofing and identity & resource id vulnerability. | |
| 54. | Which of the following is an example of physical layer vulnerability? |
| A. | mac address spoofing |
| B. | route spoofing |
| C. | weak or non-existent authentication |
| D. | keystroke & other input logging |
| Answer» D. keystroke & other input logging | |
| Explanation: keystroke & other input logging is an example of physical layer vulnerability. other such physical layer vulnerabilities are unauthorized network access, damage or destruction of data & hardware and keystroke & other input logging. | |
| 55. | Which of the following is an example of data-link layer vulnerability? |
| A. | physical theft of data |
| B. | vlan circumvention |
| C. | route spoofing |
| D. | weak or non-existent authentication |
| Answer» B. vlan circumvention | |
| Explanation: vlan circumvention is an example of data-link layer vulnerability. mac address spoofing, as well as switches, may be forced for flooding traffic to all vlan ports are some other examples of data-link layer vulnerability. | |
| 56. | Which transmission media provides the highest transmission speed in a network? |
| A. | coaxial cable |
| B. | twisted pair cable |
| C. | optical fiber |
| D. | electrical cable |
| Answer» C. optical fiber | |
| Explanation: fiber optics is considered to have the highest transmission speed among the all mentioned above. the fiber optics transmission runs at 1000mb/s. it is called as 1000base-lx whereas ieee standard for it is 802.3z. it is popularly used for modern day network connections due to its high transmission rate. | |
| 57. | Bits can be sent over guided and unguided media as analog signal by |
| A. | digital modulation |
| B. | amplitude modulation |
| C. | frequency modulation |
| D. | phase modulation |
| Answer» A. digital modulation | |
| Explanation: in analog modulation, digital low frequency baseband signal (digital bit stream) is transmitted over a higher frequency. whereas in digital modulation the only difference is that the base band signal is of discrete amplitude level. the bits are represented by only two frequency levels, one for high and one for low. | |
| 58. | The portion of physical layer that interfaces with the media access control sublayer is called |
| A. | physical signalling sublayer |
| B. | physical data sublayer |
| C. | physical address sublayer |
| D. | physical transport sublayer |
| Answer» A. physical signalling sublayer | |
| Explanation: the portion of physical layer that interfaces with the medium access control sublayer is physical signaling sublayer. the main function of this layer is character encoding, reception, decoding and performs optional isolation functions. it | |
| 59. | The physical layer provides |
| A. | mechanical specifications of electrical connectors and cables |
| B. | electrical specification of transmission line signal level |
| C. | specification for ir over optical fiber |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: anything dealing with a network cable or the standards in use – including pins, connectors and the electric current used is dealt in the physical layer (layer 1). physical layer deals with bit to bit delivery of the data aided by the various transmission mediums. | |
| 60. | In asynchronous serial communication the physical layer provides |
| A. | start and stop signalling |
| B. | flow control |
| C. | both start & stop signalling and flow control |
| D. | only start signalling |
| Answer» C. both start & stop signalling and flow control | |
| Explanation: in asynchronous serial communication, the communication is not synchronized by clock signal. instead of a start and stop signaling and flow control method is followed. unlike asynchronous serial communication, in synchronous serial communication a clock signal is used for communication, so the start and stop method is not really required. | |
| 61. | The physical layer is responsible for |
| A. | line coding |
| B. | channel coding |
| C. | modulation |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: the physical layer is | |
| 62. | The physical layer translates logical communication requests from the into hardware specific operations. |
| A. | data link layer |
| B. | network layer |
| C. | trasnport layer |
| D. | application layer |
| Answer» A. data link layer | |
| Explanation: physical layer accepts data or information from the data link layer and converts it into hardware specific operations so as to transfer the message through physical cables. some examples of the cables used are optical fiber cables, twisted pair cables and co-axial cables. | |
| 63. | A single channel is shared by multiple signals by |
| A. | analog modulation |
| B. | digital modulation |
| C. | multiplexing |
| D. | phase modulation |
| Answer» C. multiplexing | |
| Explanation: in communication and computer networks, the main goal is to share a scarce resource. this is done by multiplexing, where multiple analog or digital signals are combined into one signal over a shared medium. the multiple kinds of signals are designated by the transport layer which is the layer present on a higher level than the physical layer. | |
| 64. | Wireless transmission of signals can be done via |
| A. | radio waves |
| B. | microwaves |
| C. | infrared |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: wireless transmission is carried out by radio waves, microwaves and ir waves. these waves range from 3 khz to above 300 ghz and are more suitable for wireless transmission. radio waves can penetrate through walls and are used in radio communications, microwaves and infrared (ir) waves cannot penetrate through walls and are used for satellite communications and device communications respectively. | |
| 65. | In the digital communication system, signals in different frequency bands are |
| A. | orthogonal |
| B. | non orthogonal |
| C. | orthogonal & non orthogonal |
| D. | none of the mentioned |
| Answer» A. orthogonal | |
| Explanation: in digital communication system, signals from different frequency bands are orthogonal thus interference won’t occur. | |
| 66. | Properties of impulse function are |
| A. | symmetry |
| B. | time scaling |
| C. | shifting |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: some of the properties of impulse function are symmetry, time scaling and shifting. | |
| 67. | Properties of Fourier transform are |
| A. | duality property |
| B. | time shifting property |
| C. | modulation property |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: some of the properties of fourier transform are duality property, time scaling property, time shifting property, modulation property and many more. | |
| 68. | A base-band signal can be up-converted using |
| A. | sine wave |
| B. | cosine wave |
| C. | filtering |
| D. | none of the mentioned |
| Answer» B. cosine wave | |
| Explanation: a base-band signal can be up- converted to band-pass filter by applying cosine wave. | |
| 69. | A band-pass signal can be down-converted using |
| A. | sine wave |
| B. | cosine wave |
| C. | time delayed wave |
| D. | none of the mentioned |
| Answer» B. cosine wave | |
| Explanation: for down-conversion of a band-pass signal also cosine signal is used and multiplied with it. | |
| 70. | In down-conversion multiplication with cosine wave is followed by |
| A. | low pass filter |
| B. | high pass filter |
| C. | bandpass filter |
| D. | bandstop filter |
| Answer» A. low pass filter | |
| Explanation: downconversion of bandpass signal includes multiplication with sine wave followed by low pass filtering. | |
| 71. | Fourier transform of a signal gives the |
| A. | frequency content |
| B. | bandwidth |
| C. | frequency content & bandwidth |
| D. | none of the mentioned |
| Answer» C. frequency content & bandwidth | |
| Explanation: fourier transform of a signal give the frequency content and also determines the bandwidth of the signal. | |
| 72. | Random things in a communication system are |
| A. | timing offset |
| B. | device frequency |
| C. | attenuation |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: some of the random things in the communication system are noise in the channel, attenuation, fading, channel filtering, device frequency, phase and timing offset. | |
| 73. | Which can be used for periodic and non periodic? |
| A. | fourier series |
| B. | fourier transforms |
| C. | fourier series & transforms |
| D. | none of the mentioned |
| Answer» B. fourier transforms | |
| Explanation: fourier series is limited to only periodic signals where as fourier transforms and laplace transforms can be used for both periodic and non periodic signals. | |
| 74. | A band-pass signal has a Fourier transform equal to |
| A. | one |
| B. | zero |
| C. | infinity |
| D. | cannot be determined |
| Answer» B. zero | |
| Explanation: a band-pass signal has a fourier transform equal to zero for all value in both frequency and time domain. | |
| 76. | Which are orthonormal signal representation? | |
| A. | sine and cosine at same frequency | |
| B. | wavelets | |
| C. | complex sinusoids at a different frequency | |
| D. | all of the mentioned | |
| Answer» D. all of the mentioned | ||
| Explanation: some of the common orthonormal signal representations are sine and cosine at the same frequency, fourier serier, sinc functions centered at sampling times, wavelets etc. | ||
| 77. | Constellation diagram is plotted in |
| A. | constellation space |
| B. | signal space |
| C. | orthogonal space |
| D. | boundary space |
| Answer» B. signal space | |
| Explanation: the constellation diagram is plotted in a space called as signal space. | |
| 78. | Cumulative distributive function is |
| A. | non negative |
| B. | non decreasing |
| C. | non negative & decreasing |
| D. | none of the mentioned |
| Answer» C. non negative & decreasing | |
| Explanation: cumulative distribution function is non negative and non decreasing function. | |
| 79. | Which are non negative functions? |
| A. | |
| B. | pmf |
| C. | pdf & pmf |
| D. | none of the mentioned |
| Answer» C. pdf & pmf | |
| Explanation: pdf, pmf and cdf are non negative functions. | |
| 80. | Which of the following tasks is not done by data link layer? |
| A. | framing |
| B. | error control |
| C. | flow control |
| D. | channel coding |
| Answer» D. channel coding | |
| Explanation: channel coding is the function of physical layer. data link layer mainly deals with framing, error control and flow control. data link layer is the layer where the packets are encapsulated into frames. | |
| 81. | Which sublayer of the data link layer performs data link functions that depend upon the type of medium? |
| A. | logical link control sublayer |
| B. | media access control sublayer |
| C. | network interface control sublayer |
| D. | error control sublayer |
| Answer» B. media access control sublayer | |
| Explanation: media access control (mac) deals with transmission of data packets to and from the network-interface card, and also to and from another remotely shared channel. | |
| 82. | Header of a frame generally contains |
| A. | synchronization bytes |
| B. | addresses |
| C. | frame identifier |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: in a frame, the header is a part of the data that contains all the required information about the transmission of the file. it contains information like synchronization bytes, addresses, frame identifier etc. it also contains error control information for reducing the errors in the transmitted frames. | |
| 83. | When 2 or more bits in a data unit has been changed during the transmission, the error is called |
| A. | random error |
| B. | burst error |
| C. | inverted error |
| D. | double error |
| Answer» B. burst error | |
| Explanation: when a single bit error occurs in a data, it is called single bit error. when more than a single bit of data is corrupted or has error, it is called burst error. if a single bit error occurs, the bit can be simply repaired by inverting it, but in case of a burst error, the sender has to send the frame again. | |
| 84. | CRC stands for |
| A. | cyclic redundancy check |
| B. | code repeat check |
| C. | code redundancy check |
| D. | cyclic repeat check |
| Answer» A. cyclic redundancy check | |
| Explanation: cyclic redundancy check is a code that is added to a data which helps us to identify any error that occurred during the transmission of the data. crc is only able to detect errors, not correct them. crc is inserted in the frame trailer. | |
| 85. | Which of the following is a data link protocol? |
| A. | ethernet |
| B. | point to point protocol |
| C. | hdlc |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: there are many data link layer protocols. some of them are sdlc (synchronous data link protocol), hdlc (high level data link control), slip (serial line interface protocol), ppp (point to point protocol) etc. these protocols are used to provide the logical link control function of the data link layer. | |
| 86. | Which of the following is the multiple access protocol for channel access control? |
| A. | csma/cd |
| B. | csma/ca |
| C. | both csma/cd & csma/ca |
| D. | hdlc |
| Answer» C. both csma/cd & csma/ca | |
| Explanation: in csma/cd, it deals with detection of collision after collision has occurred, whereas csma/ca deals with preventing collision. csma/cd is abbreviation for carrier sensing multiple access/collision detection. csma/ca is abbreviation for carrier sensing multiple access/collision avoidance. these protocols are used for efficient multiple channel access. | |
| 87. | The technique of temporarily delaying outgoing acknowledgements so that they can be hooked onto the next outgoing data frame is called |
| A. | piggybacking |
| B. | cyclic redundancy check |
| C. | fletcher’s checksum |
| D. | parity check |
| Answer» A. piggybacking | |
| Explanation: piggybacking is a technique in which the acknowledgment is temporarily delayed so as to be hooked with the next outgoing data frame. it saves a lot of channel bandwidth as in non-piggybacking system, some bandwidth is reserved for acknowledgement. | |
| 88. | Automatic repeat request error management mechanism is provided by |
| A. | logical link control sublayer |
| B. | media access control sublayer |
| C. | network interface control sublayer |
| D. | application access control sublayer |
| Answer» A. logical link control sublayer | |
| Explanation: the logical link control is a sublayer of data link layer whose main function is to manage traffic, flow and error control. the automatic repeat request error management mechanism is provided by the llc when an error is found in the received frame at the receiver’s end to inform the sender to re-send the frame. | |
| 89. | In layering, n layers provide service to |
| A. | n layer |
| B. | n-1 layer |
| C. | n+1 layer |
| D. | none of the mentioned |
| Answer» C. n+1 layer | |
| Explanation: in layering n layer provides service to n+1 layer and use the service provided by n-1 layer. | |
| 90. | Which can be used as an intermediate device in between transmitter entity and receiver entity? |
| A. | ip router |
| B. | microwave router |
| C. | telephone switch |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: ip router, microwave router and telephone switch can be used as an intermediate device between communication of two entities. | |
| 91. | Which has comparatively high frequency component? |
| A. | sine wave |
| B. | cosine wave |
| C. | square wave |
| D. | none of the mentioned |
| Answer» C. square wave | |
| Explanation: square wave has comparatively high frequency component in them. | |
| 92. | Which has continuous transmission? |
| A. | asynchronous |
| B. | synchronous |
| C. | asynchronous & synchronous |
| D. | none of the mentioned |
| Answer» B. synchronous | |
| Explanation: synchronous has continuous transmission where as asynchronous have sporadic transmission. | |
| 93. | Which requires bit transitions? |
| A. | asynchronous |
| B. | synchronous |
| C. | asynchronous & synchronous |
| D. | none of the mentioned |
| Answer» B. synchronous | |
| Explanation: synchronous transmission needs bit transition. | |
| 94. | In synchronous transmission, receiver must stay synchronous for |
| A. | 4 bits |
| B. | 8 bits |
| C. | 9 bits |
| D. | 16 bits |
| Answer» C. 9 bits | |
| Explanation: in synchronous transmission, receiver must stay synchronous for 9 bits. | |
| 95. | How error detection and correction is done? |
| A. | by passing it through equalizer |
| B. | by passing it through filter |
| C. | by amplifying it |
| D. | by adding redundancy bits |
| Answer» D. by adding redundancy bits | |
| Explanation: error can be detected and corrected by adding additional information that is by adding redundancy bits. | |
| 96. | Which is more efficient? |
| A. | parity check |
| B. | cyclic redundancy check |
| C. | parity & cyclic redundancy check |
| D. | none of the mentioned |
| Answer» B. cyclic redundancy check | |
| Explanation: cyclic redundancy check is more efficient than parity check. | |
| 97. | Which can detect two bit errors? |
| A. | parity check |
| B. | cyclic redundancy check |
| C. | parity & cyclic redundancy check |
| D. | none of the mentioned |
| Answer» B. cyclic redundancy check | |
| Explanation: crc is more powerful and it can detect various kind of errors like 2 bit errors. | |
| 98. | CRC uses |
| A. | multiplication |
| B. | binary division |
| C. | multiplication & binary division |
| D. | none of the mentioned |
| Answer» C. multiplication & binary division | |
| Explanation: crc uses more math like multiplication and binary division. | |
| 99. | What is start frame delimeter (SFD) in ethernet frame? |
| A. | 10101010 |
| B. | 10101011 |
| C. | 00000000 |
| D. | 11111111 |
| Answer» B. 10101011 | |
| Explanation: the start frame delimiter is a 1 byte field in the ethernet frame that indicates that the preceding bits are the start of the frame. it is always set to 10101011. | |
| 101. | What is autonegotiation? | |
| A. | a procedure by which two connected devices choose common transmission parameters | |
| B. | a security algorithm | |
| C. | a routing algorithm | |
| D. | encryption algorithm | |
| Answer» A. a procedure by which two connected devices choose common transmission parameters | ||
| Explanation: autonegotiation is a procedure by which two connected devices choose common transmission parameters. it is a signaling mechanism used in ethernet over twisted pair cables. | ||
| 102. | Ethernet in metropolitan area network (MAN) can be used as |
| A. | pure ethernet |
| B. | ethernet over sdh |
| C. | ethernet over mpls |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: a metropolitan area network (man) that is based on ethernet standards is called an ethernet man. it is commonly used to connect nodes to the internet. businesses also use ethernet mans to connect their own offices to each other. | |
| 103. | A point-to-point protocol over ethernet is a network protocol for |
| A. | encapsulating ppp frames inside ethernet frames |
| B. | encapsulating ehternet framse inside ppp frames |
| C. | for security of ethernet frames |
| D. | for security of ppp frames |
| Answer» A. encapsulating ppp frames inside ethernet frames | |
| Explanation: ppoe or point-to-point protocol over ethernet was first introduced in 1999. it is popularly used by modern day internet service providers for dial-up connectivity. | |
| 104. | High speed ethernet works on |
| A. | coaxial cable |
| B. | twisted pair cable |
| C. | optical fiber |
| D. | unshielded twisted pair cable |
| Answer» C. optical fiber | |
| Explanation: fast ethernet is mostly used in networks along with category 5 (cat-5) copper twisted-pair cable, but it also works with fiber-optic cable. based on the cable being used, there can be three types of fast ethernet. | |
| 105. | The maximum size of payload field in ethernet frame is |
| A. | 1000 bytes |
| B. | 1200 bytes |
| C. | 1300 bytes |
| D. | 1500 bytes |
| Answer» D. 1500 bytes | |
| Explanation: the minimum size of the payload field is 40 bytes and the maximum size is 1500 bytes. if the payload size exceeds 1500 bytes, the frame is called a jumbo frame. | |
| 106. | What is interframe gap? |
| A. | idle time between frames |
| B. | idle time between frame bits |
| C. | idle time between packets |
| D. | idle time between networks |
| Answer» A. idle time between frames | |
| Explanation: the inter-frame gap is the idle time for the receiver between the incoming frame flow. the inter-frame gap must be as low as possible for idle connections. | |
| 107. | An ethernet frame that is less than the IEEE 802.3 minimum length of 64 octets is called |
| A. | short frame |
| B. | runt frame |
| C. | mini frame |
| D. | man frame |
| Answer» B. runt frame | |
| Explanation: an ethernet frame that is less than the ieee 802.3 minimum length of 64 octets is called a runt frame. such frames are a result of collisions or software malfunctions. | |
| 108. | In wireless ad-hoc network |
| A. | access point is not required |
| B. | access point is must |
| C. | nodes are not required |
| D. | all nodes are access points |
| Answer» A. access point is not required | |
| Explanation: an ad-hoc wireless network is a decentralized kind of a wireless network. an access point is usually a central device and it would go against the rules of the ad- hoc network to use one. hence it is not required. | |
| 109. | Which multiple access technique is used by IEEE 802.11 standard for wireless LAN? |
| A. | cdma |
| B. | csma/ca |
| C. | aloha |
| D. | csma/cd |
| Answer» B. csma/ca | |
| Explanation: csma/ca stands for carrier- sense multiple access/collision avoidance. it is a multiple access protocol used by ieee | |
| 110. | A wireless network interface controller can work in |
| A. | infrastructure mode |
| B. | ad-hoc mode |
| C. | both infrastructure mode and ad-hoc mode |
| D. | wds mode |
| Answer» C. both infrastructure mode and ad-hoc mode | |
| Explanation: a wireless network interface controller works on the physical layer and the data link layer of the osi model. | |
| 111. | In wireless network an extended service set is a set of |
| A. | connected basic service sets |
| B. | all stations |
| C. | all access points |
| D. | connected access points |
| Answer» A. connected basic service sets | |
| Explanation: the extended service set is a part of the ieee 802.11 wlan architecture and is used to expand the range of the basic service set by allowing connection of multiple basic service sets. | |
| 112. | Mostly is used in wireless LAN. |
| A. | time division multiplexing |
| B. | orthogonal frequency division multiplexing |
| C. | space division multiplexing |
| D. | channel division multiplexing |
| Answer» B. orthogonal frequency division multiplexing | |
| Explanation: in orthogonal frequency division multiplexing, digital data is encoded on multiple carrier frequencies. it is also used in digital television and audio broadcasting in addition to wireless lans. | |
| 113. | Which one of the following event is not possible in wireless LAN? |
| A. | collision detection |
| B. | acknowledgement of data frames |
| C. | multi-mode data transmission |
| D. | connection to wired networks |
| Answer» A. collision detection | |
| Explanation: collision detection is not possible in wireless lan with no extensions. collision detection techniques for multiple access like csma/cd are used to detect collisions in wireless lans. | |
| 114. | What is Wired Equivalent Privacy (WEP)? |
| A. | security algorithm for ethernet |
| B. | security algorithm for wireless networks |
| C. | security algorithm for usb communication |
| D. | security algorithm for emails |
| Answer» B. security algorithm for wireless networks | |
| Explanation: wep is a security algorithm for wireless network which intended to provide data confidentiality comparable to that of traditional wired networks. it was introduced in 1997. | |
| 115. | What is WPA? |
| A. | wi-fi protected access |
| B. | wired protected access |
| C. | wired process access |
| D. | wi-fi process access |
| Answer» A. wi-fi protected access | |
| Explanation: wpa or wifi protected access is a security protocol used to provide users and firms with strong data security and protection for their wireless networks (wifi) to give them confidence that only authorized users can access their network. | |
| 116. | The time required to transmit frame depends on |
| A. | frame size |
| B. | channel capacity |
| C. | frame size & channel capacity |
| D. | none of the mentioned |
| Answer» C. frame size & channel capacity | |
| Explanation: the time to transmit frame is given by the ratio of frame size and channel capacity. | |
| 117. | Window given the number of |
| A. | bytes |
| B. | frames |
| C. | bytes & frames |
| D. | none of the mentioned |
| Answer» C. bytes & frames | |
| Explanation: window gives the number of frames or bytes that can be in transit unacknowledged. | |
| 118. | Routing is |
| A. | static |
| B. | dynamic |
| C. | static & dynamic |
| D. | none of the mentioned |
| Answer» C. static & dynamic | |
| Explanation: routing can be static and dynamic. | |
| 119. | Routing is performed only centrally. |
| A. | true |
| B. | false |
| Answer» A. true | |
| Explanation: routing is performed centrally and also in fully distributed way. | |
| 120. | Which is connection oriented and which is connection-less? |
| A. | datagrams, virtual circuits |
| B. | virtual circuits, datagrams |
| C. | datagrams |
| D. | none of the mentioned |
| Answer» B. virtual circuits, datagrams | |
| Explanation: datagram is connection-less and virtual circuits are connection oriented. | |
| 121. | Which uses UDP? |
| A. | echo |
| B. | time |
| C. | domain name server |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: the protocols using udp are echo, time, domain name server, network file system etc. | |
| 122. | Which uses TCP? |
| A. | simple mail transfer protocol |
| B. | simple network management protocol |
| C. | simple mail transfer & network management protocol |
| D. | none of the mentioned |
| Answer» A. simple mail transfer protocol | |
| Explanation: some of the protocols using tcp are http, telnet, file transfer protocol, simple mail transfer protocol etc. | |
| 123. | Which tells about low level transmission and framing? |
| A. | v series |
| B. | x series |
| C. | g series |
| D. | q series |
| Answer» C. g series | |
| Explanation: g series tells about level transmission, modulation and framing. | |
| 124. | Which tells about signalling? |
| A. | v series |
| B. | x series |
| C. | g series |
| D. | q series |
| Answer» D. q series | |
| Explanation: q series tells about signalling. | |
| 126. | Bluetooth is the wireless technology for | |
| A. | local area network | |
| B. | personal area network | |
| C. | metropolitan area network | |
| D. | wide area network | |
| Answer» B. personal area network | ||
| Explanation: bluetooth is a wireless technology used to create a wireless personal area network for data transfer up to a distance | ||
| 127. | Bluetooth uses |
| A. | frequency hopping spread spectrum |
| B. | orthogonal frequency division multiplexing |
| C. | time division multiplexing |
| D. | channel division multiplexing |
| Answer» A. frequency hopping spread spectrum | |
| Explanation: frequency hopping spread spectrum is a method of transmitting radio signals by rapidly changing the carrier frequency and is controlled by the codes known to the sender and receiver only. | |
| 128. | Unauthorised access of information from a wireless device through a bluetooth connection is called |
| A. | bluemaking |
| B. | bluesnarfing |
| C. | bluestring |
| D. | bluescoping |
| Answer» B. bluesnarfing | |
| Explanation: unauthorised access of information from a wireless device through a bluetooth connection is called bluesnarfing. it is done through exploiting the vulnerabilities of the bluetooth device to steal the transmitted information. | |
| 129. | What is A2DP (advanced audio distribution profile)? |
| A. | a bluetooth profile for streaming audio |
| B. | a bluetooth profile for streaming video |
| C. | a bluetooth profile for security |
| D. | a bluetooth profile for file management |
| Answer» A. a bluetooth profile for streaming audio | |
| Explanation: a2dp stands for advanced audio distribution profile is a transfer standard use to transmit high definition audio through bluetooth. it is mainly used in bluetooth speakers and wireless headphones. | |
| 130. | Bluetooth supports |
| A. | point-to-point connections |
| B. | point-to-multipoint connection |
| C. | both point-to-point connections and point- to-multipoint connection |
| D. | multipoint to point connection |
| Answer» C. both point-to-point connections and point- to-multipoint connection | |
| Explanation: in bluetooth, each slave node communicates with the master of the piconet independently i.e. each master-slave connection is independent. the slave is not allowed to communicate with other slaves directly. | |
| 131. | A scatternet can have maximum |
| A. | 10 piconets |
| B. | 20 piconets |
| C. | 30 piconets |
| D. | 40 piconets |
| Answer» A. 10 piconets | |
| Explanation: a scatternet can have maximum of 10 piconets and minimum of 2 piconets. to connect these piconets, a slave node of one piconet may act as a master in a piconet that is part of the scatternet. | |
| 132. | What is the access point (AP) in a wireless LAN? |
| A. | device that allows wireless devices to connect to a wired network |
| B. | wireless devices itself |
| C. | both device that allows wireless devices to connect to a wired network and wireless devices itself |
| D. | all the nodes in the network |
| Answer» A. device that allows wireless devices to connect to a wired network | |
| Explanation: access point in a wireless network is any device that will allow the wireless devices to a wired network. a router is the best example of an access point. | |
| 133. | In wireless distribution system |
| A. | multiple access point are inter-connected with each other |
| B. | there is no access point |
| C. | only one access point exists |
| D. | access points are not required |
| Answer» A. multiple access point are inter-connected with each other | |
| Explanation: a wireless distribution system allows the connection of multiple access points together. it is used to expand a wireless network to a larger network. | |
| 134. | Which protocol is used to link all the devices in the IoT? |
| A. | tcp/ip |
| B. | network |
| C. | udp |
| D. | http |
| Answer» A. tcp/ip | |
| Explanation: the internet of thing is the global system of interconnected computer networks that use the internet protocol suite (tcp/ip) to link billions of devices worldwide. | |
| 135. | enables seamless integration of LoWPAN devices with internet leveraging. |
| A. | ietf 6lowpan |
| B. | ieft coap |
| C. | rfid/nfc |
| D. | ieee 802.15.4.lowpan |
| Answer» A. ietf 6lowpan | |
| Explanation: ietf 6lowpan enables seamless integration of lowpan devices with internet leveraging ipv6 large address space and appln. layer protocol reuse. | |
| 136. | enables open application layer for constrained nodes. |
| A. | ietf 6lowpan |
| B. | ieft coap |
| C. | rfid/nfc |
| D. | ieee 802.15.4.lowpan |
| Answer» B. ieft coap | |
| Explanation: ietf coap – open application | |
| 137. | tags, devices, smart phones useful in identification. |
| A. | ietf 6lowpan |
| B. | ieft coap |
| C. | rfid/nfc |
| D. | ieee 802.15.4.lowpan |
| Answer» C. rfid/nfc | |
| Explanation: rfid/nfc – tags, devices, smart phones useful in product / object identification and gathering associated information. | |
| 138. | supports low energy radio operation. |
| A. | ietf 6lowpan |
| B. | ieft coap |
| C. | rfid/nfc |
| D. | bluetooth |
| Answer» D. bluetooth | |
| Explanation: bluetooth smart devices support low energy radio operations like, heart rate monitors, blood glucose monitors suitable for health care and fitness etc. | |
| 139. | specification defining the PHY and MAC layer of low power devices. |
| A. | ietf 6lowpan |
| B. | ieft coap |
| C. | rfid/nfc |
| D. | ieee 802.15.4.lowpan |
| Answer» D. ieee 802.15.4.lowpan | |
| Explanation: ieee 802.15.4.lowpan – specification defining the phy and mac layer of low power devices supporting 250 kb/s data rate, small packet size 127 bytes. | |
| 140. | is an application layer protocol for resource constrained devices. |
| A. | coap |
| B. | hmtp |
| C. | mqtt |
| D. | tcp/ip |
| Answer» A. coap | |
| Explanation: coap is an application layer protocol (ietf draft) for resource constrained devices. adheres to the restful approach for managing the resources and support mapping to http. | |
| 141. | Adheres to approach for managing resources and support mapping to HTTP. |
| A. | retful |
| B. | iot |
| C. | restful |
| D. | restful |
| Answer» D. restful | |
| Explanation: coap is an application layer protocol (ietf draft) for resource constrained devices. adheres to restful approach for managing resources and support mapping to http. | |
| 142. | resources are identified by Uniform Resource Identifiers. |
| A. | coap |
| B. | hmtp |
| C. | mqtt |
| D. | tcp/ip |
| Answer» A. coap | |
| Explanation: coap is an application layer protocol (ietf draft) for resource constrained devices. adheres to restful approach for managing resources and support mapping to | |
| 143. | Which protocol interacts asynchronously over UDP? |
| A. | hmtp |
| B. | coap |
| C. | mqtt |
| D. | tcp/ip |
| Answer» B. coap | |
| Explanation: coap is an application layer protocol (ietf draft) for resource constrained devices. it is asynchronous message interactions over udp, request/response semantics coap resources are identified by uniform resource identifiers. | |
| 144. | CoAP messages are short. |
| A. | true |
| B. | false |
| Answer» A. true | |
| Explanation: coap messages are short – 4 bytes header followed by options (typically, 10-20 bytes header). | |
| 145. | How many messages types are there in CoAP? |
| A. | 2 |
| B. | 5 |
| C. | 3 |
| D. | 4 |
| Answer» D. 4 | |
| Explanation: four message types are: confirmable | |
| 146. | Number of methods in CoAP? |
| A. | 2 |
| B. | 5 |
| C. | 4 |
| D. | 3 |
| Answer» C. 4 | |
| Explanation: four coap methods: get | |
| 147. | A 4 byte IP address consists of |
| A. | wired sensor network |
| B. | wireless sensor network |
| C. | wired service network |
| D. | wireless service network |
| Answer» B. wireless sensor network | |
| Explanation: wsn – wireless sensor network comprises of motes running a wsn application and a light weight coap server. | |
| 148. | In virtual circuit network each packet contains |
| A. | full source and destination address |
| B. | a short vc number |
| C. | only source address |
| D. | only destination address |
| Answer» B. a short vc number | |
| Explanation: a short vc number also called as vcid (virtual circuit identifier) is a type of identifier which is used to distinguish between several virtual circuits in a connection oriented circuit switched network. each virtual circuit is used to transfer data over a larger packet switched network. | |
| 149. | A subset of a network that includes all the routers but contains no loops is called |
| A. | spanning tree |
| B. | spider structure |
| C. | spider tree |
| D. | special tree |
| Answer» A. spanning tree | |
| Explanation: spanning tree protocol (stp) is a network protocol that creates a loop free logical topology for ethernet networks. it is a layer 2 protocol that runs on bridges and switches. the main purpose of stp is to ensure that you do not create loops when you have redundant paths in your network. | |
| 151. | Most packet switches use this principle | |
| A. | stop and wait | |
| B. | store and forward | |
| C. | store and wait | |
| D. | stop and forward | |
| Answer» B. store and forward | ||
| Explanation: the packet switch will not transmit the first bit to outbound link until it receives the entire packet. if the entire packet is not received and the time-out period expires, the packet switch will inform the sender to resend the part of packet or the entire packet based on the algorithm being used. | ||
| 152. | If there are N routers from source to destination, the total end to end delay in sending packet P(L-> number of bits in the packet R-> transmission rate) is equal to |
| A. | n |
| B. | (n*l)/r |
| C. | (2n*l)/r |
| D. | l/r |
| Answer» B. (n*l)/r | |
| Explanation: the equation to find the end to end delay when no. of bits, transmission rate and no. of routers is given by (n*l)/r. the total end to end delay, that is, nodal delay is the sum of all, the processing delay, queuing delay, transmission delay and propagation delay. | |
| 153. | What are the Methods to move data through a network of links and switches? |
| A. | packet switching and line switching |
| B. | circuit switching and line switching |
| C. | line switching and bit switching |
| D. | packet switching and circuit switching |
| Answer» D. packet switching and circuit switching | |
| Explanation: packet switching and circuit switching are two different types of switching methods used to connect the multiple communicating devices with one another. | |
| 154. | The required resources for communication between end systems are reserved for the duration of the session between end systems in method. |
| A. | packet switching |
| B. | circuit switching |
| C. | line switching |
| D. | frequency switching |
| Answer» B. circuit switching | |
| Explanation: in circuit switching, a physical path between the sender and receiver is established. this path is maintained until the connection is needed. circuit switching is implemented in the physical layer and is used in telephonic systems. | |
| 155. | As the resources are reserved between two communicating end systems in circuit switching, is achieved. |
| A. | authentication |
| B. | guaranteed constant rate |
| C. | reliability |
| D. | store and forward |
| Answer» B. guaranteed constant rate | |
| Explanation: circuit switching is connection oriented and is always implemented in the physical layer. once a path is set, all transmission occurs through the same path. it is used since the early times in telephonic systems. | |
| 156. | In systems, resources are allocated on demand. |
| A. | packet switching |
| B. | circuit switching |
| C. | line switching |
| D. | frequency switching |
| Answer» A. packet switching | |
| Explanation: in packet switching, the bits are received in out of order and need to be assembled at the receiver end, whereas in the case of circuit switching, all the bits are received in order. all transmissions may not occur through the same path in case of packet switching. | |
| 157. | Which of the following is not an application layer service? |
| A. | network virtual terminal |
| B. | file transfer, access, and management |
| C. | mail service |
| D. | error control |
| Answer» D. error control | |
| Explanation: application layer is the topmost layer in the osi model. network virtual terminal, mail service, file transfer, access and management are all services of the application layer. it uses protocols like http, ftp, and dns etc. to provide these services. | |
| 158. | Which of the following is not applicable for IP? |
| A. | error reporting |
| B. | handle addressing conventions |
| C. | datagram format |
| D. | packet handling conventions |
| Answer» A. error reporting | |
| Explanation: the internet protocol is the networking protocol which establishes the internet by relaying datagrams across network boundaries. icmp is a supporting protocol for ip which handles the error reporting functionality. | |
| 159. | Which of the following field in IPv4 datagram is not related to fragmentation? |
| A. | flags |
| B. | offset |
| C. | tos |
| D. | identifier |
| Answer» C. tos | |
| Explanation: tos-type of service identifies the type of packets. it is not related to fragmentation but is used to request specific treatment such as high throughput, high reliability or low latency for the ip packet depending upon the type of service it belongs to. | |
| 160. | The TTL field has value 10. How many routers (max) can process this datagram? |
| A. | 11 |
| B. | 5 |
| C. | 10 |
| D. | 1 |
| Answer» C. 10 | |
| Explanation: ttl stands for time to live. this field specifies the life of the ip packet based on the number of hops it makes (number of routers it goes through). ttl field is decremented by one each time the datagram is processed by a router. when the value is 0, the packet is automatically destroyed. | |
| 161. | If the value in protocol field is 17, the transport layer protocol used is |
| A. | tcp |
| B. | udp |
| C. | icmp |
| D. | igmp |
| Answer» B. udp | |
| Explanation: the protocol field enables the demultiplexing feature so that the ip protocol can be used to carry payloads of more than one protocol type. its most used values are 17 and 6 for udp and tcp respectively. icmp and igmp are network layer protocols. | |
| 162. | The data field cannot carry which of the following? |
| A. | tcp segment |
| B. | udp segment |
| C. | icmp messages |
| D. | smtp messages |
| Answer» C. icmp messages | |
| Explanation: data field usually has transport layer segments, but it can also carry icmp messages. smtp is an application layer protocol. first it must go through the transport layer to be converted into tcp segments and then it can be inserted into ip packets. | |
| 163. | What should be the flag value to indicate the last fragment? |
| A. | 0 |
| B. | 1 |
| C. | ttl value |
| D. | protocol field value |
| Answer» A. 0 | |
| Explanation: the flag field in the ip header is used to control and identify the fragments. it contains three bits: reserved, don’t fragment and more fragments. if the more fragments bit is 0, it means that the fragment is the last fragment. | |
| 164. | Which of these is not applicable for IP protocol? |
| A. | is connectionless |
| B. | offer reliable service |
| C. | offer unreliable service |
| D. | does not offer error reporting |
| Answer» B. offer reliable service | |
| Explanation: ip does not provide reliable delivery service for the data. it’s dependent upon the transport layer protocols like tcp to offer reliability. | |
| 165. | Which of the following demerits does Fragmentation have? |
| A. | complicates routers |
| B. | open to dos attack |
| C. | overlapping of fragments. |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: fragmentation makes the implementation of the ip protocol complex and can also be exploited by attackers to create a dos attack such as a teardrop attack. fragmentation won’t be required if the transport layer protocols perform wise segmentation. | |
| 166. | Which field helps to check rearrangement of the fragments? |
| A. | offset |
| B. | flag |
| C. | ttl |
| D. | identifer |
| Answer» A. offset | |
| Explanation: the fragment offset field specifies where the fragment fits in the original datagram. the offset of the first fragment will always be 0. the size of the field (13 bits) is 3-bits shorter than the size of the total length field (16 bits). | |
| 167. | Which one of the following is not a function of network layer? |
| A. | routing |
| B. | inter-networking |
| C. | congestion control |
| D. | error control |
| Answer» D. error control | |
| Explanation: in the osi model, network layer is the third layer and it provides data routing paths for network communications. error control is a function of the data link layer and the transport layer. | |
| 168. | A 4 byte IP address consists of |
| A. | only network address |
| B. | only host address |
| C. | network address & host address |
| D. | network address & mac address |
| Answer» C. network address & host address | |
| Explanation: an ip address which is 32 bits long, that means it is of 4 bytes and is composed of a network and host portion and it depends on address class. the size of the host address and network address depends upon the class of the address in classful ip addressing. | |
| 169. | Which of the following routing algorithms can be used for network layer design? |
| A. | shortest path algorithm |
| B. | distance vector routing |
| C. | link state routing |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: the routing algorithm is what decides where a packet should go next. there are several routing techniques like shortest path algorithm, static and dynamic routing, decentralized routing, distance vector routing, link state routing, hierarchical routing etc. | |
| 170. | Which of the following is not correct in relation to multi-destination routing? |
| A. | is same as broadcast routing |
| B. | contains the list of all destinations |
| C. | data is not sent by packets |
| D. | there are multiple receivers |
| Answer» C. data is not sent by packets | |
| Explanation: in multi-destination routing, there is more than one receiver and the route for each destination which is contained in a list of destinations is to be found by the routing algorithm. multi-destination routing is also used in broadcasting. | |
| 171. | Which one of the following algorithm is not used for congestion control? |
| A. | traffic aware routing |
| B. | admission control |
| C. | load shedding |
| D. | routing information protocol |
| Answer» D. routing information protocol | |
| Explanation: the routing information protocol (rip) is used by the network layer for the function of dynamic routing. | |
| 172. | The network layer protocol for internet is |
| A. | ethernet |
| B. | internet protocol |
| C. | hypertext transfer protocol |
| D. | file transfer protocol |
| Answer» B. internet protocol | |
| Explanation: there are several protocols used in network layer. some of them are ip, icmp, clnp, arp, ipx, hrsp etc. | |
| 173. | Which type of Ethernet framing is used for TCP/IP and DEC net? |
| A. | ethernet 802.3 |
| B. | ethernet 802.2 |
| C. | ethernet ii |
| D. | ethernet snap |
| Answer» C. ethernet ii | |
| Explanation: the ethernet 802.3 framing is used for netware versions 2 to 3.11, and the ethernet 802.2 framing is used for netware versions 3.12 and later plus osi routing, ethernet ii is used with tcp/ip and dec net, and ethernet snap is used with tcp/ip and appletalk. the type field in ethernet 802.2 frame is replaced by a length field in ethernet 802.3. | |
| 174. | Consider a situation in which you are a system administrator on a NetWare network, you are running NetWare 4.11 and you cannot communicate with your router. What is the likely problem? |
| A. | netware 4.11 defaults to 802.2 encapsulation |
| B. | netware 4.11 defaults to 802.3 encapsulation |
| C. | cisco routers only work with netware 3.11 |
| D. | netware 3.11 defaults to 802.2 encapsulation |
| Answer» A. netware 4.11 defaults to 802.2 encapsulation | |
| Explanation: the default encapsulation on cisco routers is novell ethernet_802.3 and netware 3.12and later defaults to 802.2 encapsulation, 3.11 and earlier defaults to 802.3. | |
| 176. | Which NetWare protocol works on layer 3– network layer—of the OSI model? | |
| A. | ipx | |
| B. | ncp | |
| C. | spx | |
| D. | netbios | |
| Answer» A. ipx | ||
| Explanation: ipx (internetwork packet exchange) is the netware network layer 3 protocol used for transferring information on lans that use novell’s netware. | ||
| 177. | Which NetWare protocol provides link- state routing? |
| A. | nlsp |
| B. | rip |
| C. | sap |
| D. | ncp |
| Answer» A. nlsp | |
| Explanation: netware link services protocol (nlsp) provides link-state routing. | |
| 178. | As a system administrator, you want to debug IGRP but are worried that the “debug IP IGRP transaction” command will flood the console. What is the command that you should use? |
| A. | debug ip igrp event |
| B. | debug ip igrp-events |
| C. | debug ip igrp summary |
| D. | debug ip igrp events |
| Answer» D. debug ip igrp events | |
| Explanation: the “debug ip igrp events” is used to display a short summary of igrp routing information. you can append an ip address onto either console’s command-line to see only the igrp updates from a neighbor. the command will only give a short summary and hence won’t flood the command line. | |
| 179. | 0.0.0 router IGRP 109 network 172.68.7.0 |
| A. | it isolates networks 10.0.0.0 and 172.68.7.0 |
| B. | it loads igrp for networks 109 and 71 |
| C. | it disables rip |
| D. | it disables all routing protocols |
| Answer» A. it isolates networks 10.0.0.0 and 172.68.7.0 | |
| Explanation: it isolates network 10.0.0.0 and | |
| 180. | As a system administrator, you need to set up one Ethernet interface on the Cisco router to allow for both sap and Novell-ether encapsulations. Which set of commands will accomplish this? |
| A. | interface ethernet 0.1 ipx encapsulation novell-ether ipx network 9e interface ethernet 0.2 ipx network 6c |
| B. | interface ethernet 0 ipx encapsulation novell-ether ipx network 9e interface ethernet 0 ipx encapsulation sap ipx network 6c |
| C. | interface ethernet 0.1 ipx encapsulation novell-ether interface ethernet 0.2 ipx encapsulation sap |
| D. | interface ethernet 0.1ipx encapsulation novell-ether ipx network 9e interface ethernet 0.2 ipx encapsulation sap ipx network 6c |
| Answer» D. interface ethernet 0.1ipx encapsulation novell-ether ipx network 9e interface ethernet 0.2 ipx encapsulation sap ipx network 6c | |
| Explanation: the following commands setup the sub interfaces to allow for two types of encapsulation:interface ethernet 0.1 ipx encapsulation novell-ether ipx network 9e interface ethernet0.2 ipx encapsulation sap ipx network 6c. | |
| 181. | What does the “IPX maximum-paths 2” command accomplish? |
| A. | it enables load sharing on 2 paths if the paths are equal metric paths |
| B. | it sets up routing to go to network 2 |
| C. | it is the default for cisco ipx load sharing |
| D. | it enables load sharing on 2 paths if the paths are unequal metric paths |
| Answer» A. it enables load sharing on 2 paths if the paths are equal metric paths | |
| Explanation: it enables load sharing on 2 paths if the paths are equal metric paths. the default is 1 path and the maximum is 512 paths. the value must always be greater than 1 and must be a natural number. | |
| 182. | You want to enable both arpa and snap encapsulation on one router interface. How do you do this? |
| A. | the interface can handle multiple encapsulation types with no extra configuration |
| B. | assign two network numbers, one for each encapsulation type |
| C. | enable novell-ether to run multiple encapsulation types |
| D. | both arpa and snap are enabled by default so you don’t have to configure anything |
| Answer» B. assign two network numbers, one for each encapsulation type | |
| Explanation: to assign multiple network numbers, you usually use sub interfaces. a sample configuration follows: ipxethernet | |
| 183. | By default, Cisco routers forward GNS SAPs to remote networks. |
| A. | false |
| B. | true |
| Answer» A. false | |
| Explanation: gns is novell’s protocol to get nearest server. if there is a server on the local network,that server will respond. if there isn’t, the cisco router has to be configured to forward thegns sap. | |
| 184. | To prevent Service Advertisements (SAPs) from flooding a network, Cisco routers do not forward them. How are services advertised to other networks? |
| A. | each router builds its own sap table and forwards that every 60 seconds |
| B. | each router assigns a service number and broadcasts that |
| C. | saps aren’t necessary with cisco routers |
| D. | cisco routers filter out all saps |
| Answer» A. each router builds its own sap table and forwards that every 60 seconds | |
| Explanation: cisco routers build sap tables and forward the table every 60 seconds. all saps can’t befiltered even with 4.x since nds and time synchronization uses saps. | |
| 185. | Novell’s implementation of RIP updates routing tables every seconds. |
| A. | 60 |
| B. | 90 |
| C. | 10 |
| D. | 30 |
| Answer» A. 60 | |
| Explanation: novell’s rip updates routing tables every 60 seconds, apple’s rtmp is every 10 seconds, routers arp every 60 seconds, igrp signal every 90 seconds, and banyan vines signals every 90 seconds. | |
| 186. | In Novell’s use of RIP, there are two metrics used to make routing decisions. Select the correct metrics. |
| A. | ticks & hops |
| B. | hops & loops |
| C. | loops & counts |
| D. | counts & ticks |
| Answer» A. ticks & hops | |
| Explanation: it first uses ticks (which is about 1/18 sec.); if there is a tie, it uses hops; if hops are equal, then it uses an administratively assigned tiebreaker. | |
| 187. | The term that is used to place packet in its route to its destination is called |
| A. | delayed |
| B. | urgent |
| C. | forwarding |
| D. | delivering |
| Answer» C. forwarding | |
| Explanation: forwarding is done by the nodes in the path from source to destination, that are not the intended destination for the packet in order to pass the packet to the next node in the path. the destination machine does not forward the packet to any other node. | |
| 188. | A second technique to reduce routing table and simplify searching process is called |
| A. | network-specific method |
| B. | network-specific motion |
| C. | network-specific maintaining |
| D. | network-specific membership |
| Answer» A. network-specific method | |
| Explanation: in the network specific forwarding method, there is only one record, the destination of the packet, in the routing table and not the other hosts of the network. the other two forwarding methods are the default method and the next-hop method. | |
| 189. | Next-Hop Method is used to reduce contents of a |
| A. | revolving table |
| B. | rotating table |
| C. | routing table |
| D. | re-allocate table |
| Answer» C. routing table | |
| Explanation: in the next-hop forwarding method, the routing table of each router in the path contains the address of only the next hop in the path of packet. this method is suitable for short distances only. | |
| 190. | In Unicast routing, if instability is between three nodes, stability cannot be |
| A. | stable |
| B. | reversed |
| C. | guaranteed |
| D. | forward |
| Answer» C. guaranteed | |
| Explanation: in unicast routing, there is only sender and one receiver. so, if there is instability between three nodes, in which one is sender, one is receiver and one is the router in the path, there is no other path available for the packet and the stability of the network is not guaranteed. | |
| 191. | RPF stands for |
| A. | reverse path forwarding |
| B. | reverse path failure |
| C. | reverse packet forwarding |
| D. | reverse protocol failure |
| Answer» A. reverse path forwarding | |
| Explanation: reverse path forwarding is a loop-free forwarding method for multi-cast routing in modern systems. the method focuses on forwarding the packet away from the source ip in each iteration to make sure there is no loops. | |
| 192. | LSP stands for |
| A. | link stable packet |
| B. | link state packet |
| C. | link state protocol |
| D. | link state path |
| Answer» B. link state packet | |
| Explanation: a link state packet is a packet created by a router that lists its neighboring nodes and routers in link state routing protocol. it is shared with other routers to find the shortest path from a source to the destination. | |
| 193. | Protocol is a set of |
| A. | formats |
| B. | procedures |
| C. | formats & procedures |
| D. | none of the mentioned |
| Answer» C. formats & procedures | |
| Explanation: protocol is a set of procedures and formats that entities use to communicate information. | |
| 194. | Several techniques can make size of routing table manageable and also handle issues such as |
| A. | maturity |
| B. | error reporting |
| C. | tunneling |
| D. | security |
| Answer» D. security | |
| Explanation: the size of the routing table in the technique must be manageable for the network nodes i.e. it must not be too big. | |
| 195. | Host-specific routing is used for purposes such as checking route or providing |
| A. | network measures |
| B. | security measures |
| C. | routing measures |
| D. | delivery measures |
| Answer» B. security measures | |
| Explanation: in host-specific routing, the | |
| 196. | In Unicast Routing, Dijkstra algorithm creates a shortest path tree from a |
| A. | graph |
| B. | tree |
| C. | network |
| D. | link |
| Answer» A. graph | |
| Explanation: the djikstra’s shortest path algorithm is the fastest among the algorithms for finding the shortest path in a graph. but it is a greedy method based algorithm so it does not guarantee the shortest path every time. | |
| 197. | In Multicast Routing Protocol, flooding is used to broadcast packets but it creates |
| A. | gaps |
| B. | loops |
| C. | holes |
| D. | links |
| Answer» B. loops | |
| Explanation: in multicast routing, there is one sender and many receivers. so flooding is | |
| 198. | The computation of the shortest path in OSPF is usually done by |
| A. | bellman-ford algorithm |
| B. | routing information protocol |
| C. | dijkstra’s algorithm |
| D. | distance vector routing |
| Answer» C. dijkstra’s algorithm | |
| Explanation: shortest path in ospf is usually computed by dijkstra’s algorithm. it was proposed by edsger w. dijkstra in the year 1956. it is a greedy method algorithm and hence may not guarantee the shortest path every time, but is really fast. | |
| 199. | Which of the following is false with respect to the features of OSPF? |
| A. | support for fixed-length subnetting by including the subnet mask in the routing message |
| B. | more flexible link cost than can range from 1 to 65535 |
| C. | use of designated router |
| D. | distribution of traffic over multiple paths that have equal cost to the destination |
| Answer» A. support for fixed-length subnetting by including the subnet mask in the routing message | |
| Explanation: ospf provides support for variable-length sunbathing by including the subnet mask in the routing message. for fixed length subnets, there is no requirement for including the subnet mask in the routing message as there is just one subnet mask for all the subnets. | |
| 201. | Which of the following is not a type of OSPF packet? | |
| A. | hello | |
| B. | link-state request | |
| C. | link-state response | |
| D. | link-state ack | |
| Answer» C. link-state response | ||
| Explanation: the five types of ospf packets are: hello, database description, link-state request, link-state update, and link-state ack. there is no link-state response packet; the neighbor router sends a link-state update packet as a response to the link-state request packet if there is an update in the routing table. | ||
| 202. | In OSPF header, which field is used to detect errors in the packet? |
| A. | type |
| B. | area id |
| C. | authentication type |
| D. | checksum |
| Answer» D. checksum | |
| Explanation: checksum field is used to detect errors. it makes sure that the data portions that are being sent are all in integrity. it can detect duplicated bits. once an error is detected, the sender has to re-transmit the data as it won’t receive an acknowledgement. | |
| 203. | In OSPF database descriptor packet, if there are more database descriptor packets in the flow, ‘M’ field is set to |
| A. | 1 |
| B. | 0 |
| C. | more |
| D. | -1 |
| Answer» A. 1 | |
| Explanation: the “m” bit is the more bit, which indicates that there are more packets to be received in the descriptor packet flow whenever it is set to 1. there is also an “i” bit which indicates if the packet is first in the flow. | |
| 204. | In OSPF database descriptor packet, which field is used to indicate that the router is master? |
| A. | m |
| B. | ms |
| C. | i |
| D. | options |
| Answer» B. ms | |
| Explanation: the ms bit is used to indicate if the origin of the packet is a master or a slave. if it is set to 1, the source of the packet is a master, and if it is set to 0, the source of the packet is a slave. | |
| 205. | In OSPF database descriptor packet, which field is used to detect a missing packet? |
| A. | lsa header |
| B. | ms |
| C. | database descriptor sequence number |
| D. | options |
| Answer» C. database descriptor sequence number | |
| Explanation: sequence number field is used to detect a missing packet. the packets are to be received in order of the sequence number, so if the receiver detects that there is a sequence number skipped or missing in the order, it stops processing the further received packets and informs the sender to retransmit the packets in sequence. | |
| 206. | The size of an IP address in IPv6 is |
| A. | 4 bytes |
| B. | 128 bits |
| C. | 8 bytes |
| D. | 100 bits |
| Answer» B. 128 bits | |
| Explanation: an ipv6 address is 128 bits long. therefore, 2128 i.e. 340 undecillion addresses are possible in ipv6. ipv4 has only 4 billion possible addresses and ipv6 would be a brilliant alternative in case ipv4 runs out of possible new addresses. | |
| 207. | The header length of an IPv6 datagram is |
| A. | 10bytes |
| B. | 25bytes |
| C. | 30bytes |
| D. | 40bytes |
| Answer» D. 40bytes | |
| Explanation: ipv6 datagram has fixed header length of 40bytes, which results in faster processing of the datagram. there is one fixed header and optional headers which may or may not exist. the fixed header contains the mandatory essential information about the | |
| 208. | In the IPv6 header, the traffic class field is similar to which field in the IPv4 header? |
| A. | fragmentation field |
| B. | fast-switching |
| C. | tos field |
| D. | option field |
| Answer» C. tos field | |
| Explanation: the traffic class field is used to specify the priority of the ip packet which is a similar functionality to the type of service field in the ipv4 header. it’s an 8-bit field and its values are not defined in the rfc 2460. | |
| 209. | IPv6 does not use type of address. |
| A. | broadcast |
| B. | multicast |
| C. | anycast |
| D. | unicast |
| Answer» A. broadcast | |
| Explanation: there is no concept of broadcast address in ipv6. instead, there is an anycast address in ipv6 which allows sending messages to a group of devices but not all devices in a network. anycast address is not standardized in ipv4. | |
| 210. | Which among the following features is |
| A. | hop limit |
| B. | ttl |
| C. | next header |
| D. | type of traffic |
| Answer» A. hop limit | |
| Explanation: the hop limit value is decremented by one by a router when the datagram is forwarded by the router. when the value becomes zero the datagram is discarded. the field is 8-bits wide, so an ipv6 packet can live up to 255 router hops only. | |
| 211. | Dual-stack approach refers to |
| A. | implementing ipv4 with 2 stacks |
| B. | implementing ipv6 with 2 stacks |
| C. | node has both ipv4 and ipv6 support |
| D. | implementing a mac address with 2 stacks |
| Answer» C. node has both ipv4 and ipv6 support | |
| Explanation: dual-stack is one of the approaches used to support ipv6 in already existing systems. isps are using it as a method to transfer from ipv4 to ipv6 completely eventually due to the lower number of possible available addresses in ipv4. | |
| 212. | The field determines the lifetime of IPv6 datagram |
| A. | use dual-stack approach |
| B. | tunneling |
| C. | no solution |
| D. | replace the system |
| Answer» B. tunneling | |
| Explanation: the ipv4 routers can form a tunnel in which at the sender’s side, the ipv6 datagram is encapsulated in to ipv4, and at the receiver’s side of the tunnel, the ipv4 packet is stripped and the ipv6 packet is sent to the receiver. | |
| 213. | Teredo is an automatic tunneling technique. In each client the obfuscated IPv4 address is represented by bits |
| A. | 96 to 127 |
| B. | 0 to 63 |
| C. | 80 to 95 |
| D. | 64 to 79 |
| Answer» A. 96 to 127 | |
| Explanation: teredo is a technique through which gives the possibility for full ipv6 network connectivity to ipv6 capable hosts which are currently on an ipv4 network. bits 96 to 127 in the datagram represents obfuscated 1pv4 address of the ipv4 network. | |
| 214. | An endpoint of an inter-process communication flow across a computer network is called |
| A. | socket |
| B. | pipe |
| C. | port |
| D. | machine |
| Answer» A. socket | |
| Explanation: socket is one end point in a two way communication link in the network. tcp layer can identify the application that data is destined to be sent by using the port number that is bound to socket. | |
| 215. | Which one of the following is a version of UDP with congestion control? |
| A. | datagram congestion control protocol |
| B. | stream control transmission protocol |
| C. | structured stream transport |
| D. | user congestion control protocol |
| Answer» A. datagram congestion control protocol | |
| Explanation: the datagram congestion control is a transport layer protocol which deals with reliable connection setup, teardown, congestion control, explicit congestion notification, and feature negotiation. it is used in modern day systems where there are really high chances of congestion. the protocol was last updated in the year 2008. | |
| 216. | Which of the following is a transport layer protocol? |
| A. | stream control transmission protocol |
| B. | internet control message protocol |
| C. | neighbor discovery protocol |
| D. | dynamic host configuration protocol |
| Answer» A. stream control transmission protocol | |
| Explanation: the stream control transmission protocol (sctp) is a transport layer protocol used in networking system where streams of data are to be continuously transmitted between two connected network nodes. some of the other transport layer protocols are rdp, rudp, tcp, dccp, udp etc. | |
| 217. | 2 USER DATAGRAM PROTOCOLS (UDP) |
| A. | connection-oriented |
| B. | unreliable |
| C. | transport layer protocol |
| D. | low overhead |
| Answer» A. connection-oriented | |
| Explanation: udp is an unreliable, connectionless transport layer protocol that provides message-based data transmission. tcp is an example of connection-oriented protocols. | |
| 218. | Return value of the UDP port “Chargen” is |
| A. | string of characters |
| B. | string of integers |
| C. | array of characters with integers |
| D. | array of zero’s and one’s |
| Answer» A. string of characters | |
| Explanation: using chargen with udp on port 19, the server sends a udp datagram containing a random number of characters every time it receives a datagram from the connecting host. the number of characters is between 0 and 512. | |
| 219. | Beyond IP, UDP provides additional services such as |
| A. | routing and switching |
| B. | sending and receiving of packets |
| C. | multiplexing and demultiplexing |
| D. | demultiplexing and error checking |
| Answer» D. demultiplexing and error checking | |
| Explanation: de-multiplexing is the delivering of received segments to the correct application layer processes at the recipients end using udp. error checking is done through checksum in udp. | |
| 220. | What is the main advantage of UDP? |
| A. | more overload |
| B. | reliable |
| C. | low overhead |
| D. | fast |
| Answer» C. low overhead | |
| Explanation: as udp does not provide assurance of delivery of packet, reliability and other services, the overhead taken to provide these services is reduced in udp’s operation. thus, udp provides low overhead, and higher speed. | |
| 221. | What is the header size of a UDP packet? |
| A. | 8 bytes |
| B. | 8 bits |
| C. | 16 bytes |
| D. | 124 bytes |
| Answer» A. 8 bytes | |
| Explanation: the fixed size of the udp packet header is 8 bytes. it contains four two- byte fields: source port address, destination port address, length of packet, and checksum. | |
| 222. | The port number is “ephemeral port number”, if the source host is |
| A. | ntp |
| B. | echo |
| C. | server |
| D. | client |
| Answer» D. client | |
| Explanation: port numbers from 1025 to 5000 are used as ephemeral port numbers in windows operating system. ephemeral port numbers are short-lived port numbers which can be used for clients in a udp system where there are temporary clients all the time. | |
| 223. | “Total length” field in UDP packet header is the length of |
| A. | only udp header |
| B. | only data |
| C. | only checksum |
| D. | udp header plus data |
| Answer» D. udp header plus data | |
| Explanation: total length is the 16 bit field which contains the length of udp header and the data. the maximum value of the total length field and the maximum size of a udp datagram is 65,535 bytes (8 byte header + 65,527 bytes of data). | |
| 224. | Which is the correct expression for the length of UDP datagram? |
| A. | udp length = ip length – ip header’s length |
| B. | udp length = udp length – udp header’s length |
| C. | udp length = ip length + ip header’s length |
| D. | udp length = udp length + udp header’s length |
| Answer» A. udp length = ip length – ip header’s length | |
| Explanation: a user datagram is encapsulated in an ip datagram. there is a field in the ip header that defines the total length of the ip packet. there is another field in the ip header that defines the length of the header. so if we subtract the length of the ip header that is encapsulated in the ip packet, we get the length of udp datagram. | |
| 226. | Which of the following is false with respect to TCP? | |
| A. | connection-oriented | |
| B. | process-to-process | |
| C. | transport layer protocol | |
| D. | unreliable | |
| Answer» D. unreliable | ||
| Explanation: tcp is a transport layer protocol that provides reliable and ordered delivery of a stream of bytes between hosts communicating via an ip network. | ||
| 227. | In TCP, sending and receiving data is done as |
| A. | stream of bytes |
| B. | sequence of characters |
| C. | lines of data |
| D. | packets |
| Answer» A. stream of bytes | |
| Explanation: tcp provides stream oriented delivery between hosts communicating via an ip network and there are no message boundaries. tcp can concatenate data from a number of send () commands into one stream of data and still transmit it reliably. | |
| 228. | TCP groups a number of bytes together into a packet called |
| A. | packet |
| B. | buffer |
| C. | segment |
| D. | stack |
| Answer» C. segment | |
| Explanation: a segment may be collection of data from many send () statements. tcp transmits each segment as a stream of bytes. | |
| 229. | Communication offered by TCP is |
| A. | full-duplex |
| B. | half-duplex |
| C. | semi-duplex |
| D. | byte by byte |
| Answer» A. full-duplex | |
| Explanation: data can flow both the directions at the same time during a tcp communication hence, it is full-duplex. this is the reason why tcp is used in systems that require full-duplex operation such as e-mail systems. | |
| 230. | Suppose a TCP connection is transferring a file of 1000 bytes. The first byte is numbered 10001. What is the sequence number of the segment if all data is sent in only one segment? |
| A. | 10000 |
| B. | 10001 |
| C. | 12001 |
| D. | 11001 |
| Answer» B. 10001 | |
| Explanation: the sequence number given to first byte of a segment, with respect to its order among the previous segments, is the sequence number of that segment. | |
| 231. | Bytes of data being transferred in each connection are numbered by TCP. These numbers start with a |
| A. | fixed number |
| B. | random sequence of 0’s and 1’s |
| C. | one |
| D. | sequence of zero’s and one’s |
| Answer» D. sequence of zero’s and one’s | |
| Explanation: one might expect the sequence number of the first byte in the stream to be 0, or 1. but that does not happen in tcp, instead, the sender has to choose an initial sequence number (isn), which is basically a | |
| 232. | The value of acknowledgement field in a segment defines |
| A. | sequence number of the byte received previously |
| B. | total number of bytes to receive |
| C. | sequence number of the next byte to be received |
| D. | sequence of zeros and ones |
| Answer» C. sequence number of the next byte to be received | |
| Explanation: the acknowledgement field in a segment defines the sequence number of the byte which is to be received next i.e. sequence number of byte that the sender should transmit next. | |
| 233. | Two broad categories of congestion control are |
| A. | open-loop and closed-loop |
| B. | open-control and closed-control |
| C. | active control and passive control |
| D. | active loop and passive loop |
| Answer» A. open-loop and closed-loop | |
| Explanation: open loop congestion control techniques are used to prevent congestion before it even happens by enforcing certain policies. closed loop congestion control techniques are used to treat congestion after it has happened. | |
| 234. | Retransmission of packets must not be done when |
| A. | packet is lost |
| B. | packet is corrupted |
| C. | packet is needed |
| D. | packet is error-free |
| Answer» D. packet is error-free | |
| Explanation: retransmission refers to the sender having to resend the packet to the receiver. it needs to be done only when some anomaly occurs with the packet like when the packet is lost or corrupted. | |
| 235. | In Go-Back-N window, when the timer of the packet times out, several packets have to be resent even some may have arrived safe. Whereas in Selective Repeat window, the sender resends |
| A. | packet which are not lost |
| B. | only those packets which are lost or corrupted |
| C. | packet from starting |
| D. | all the packets |
| Answer» B. only those packets which are lost or corrupted | |
| Explanation: in selective repeat, the sender side uses a searching algorithm to find the packets which need to be retransmitted based on the negative acknowledgements received and then resends only those packets thus saving bandwidth. | |
| 236. | Closed-Loop control mechanisms try to |
| A. | remove after congestion occurs |
| B. | remove after sometime |
| C. | prevent before congestion occurs |
| D. | prevent before sending packets |
| Answer» A. remove after congestion occurs | |
| Explanation: in closed loop congestion control, methods are implemented to remove congestion after it occurs. some of the methods used are backpressure and choke packet. | |
| 237. | The technique in which a congested node stops receiving data from the immediate upstream node or nodes is called as |
| A. | admission policy |
| B. | backpressure |
| C. | forward signaling |
| D. | backward signaling |
| Answer» B. backpressure | |
| Explanation: in this closed loop congestion control technique, the congested node propagates in the opposite direction of the data flow to inform the predecessor node to reduce the flow of packets. this is why this technique is called a node-to-node congestion control technique. | |
| 238. | The packet sent by a node to the source to inform it of congestion is called |
| A. | explicit |
| B. | discard |
| C. | choke |
| D. | backpressure |
| Answer» C. choke | |
| Explanation: choke packet is sent by a node to the source to inform it of congestion. two choke packet techniques can be used for the operation called hop-by-hop choke packet and source choke packet. | |
| 239. | In the slow-start algorithm, the size of the congestion window increases until it reaches a threshold. |
| A. | exponentially |
| B. | additively |
| C. | multiplicatively |
| D. | suddenly |
| Answer» A. exponentially | |
| Explanation: in slow-start algorithm, the size of the congestion window increases exponentially until it reaches a threshold. | |
| 240. | Which is not a application layer protocol? |
| A. | http |
| B. | smtp |
| C. | ftp |
| D. | tcp |
| Answer» D. tcp | |
| Explanation: tcp is transport layer protocol. | |
| 241. | The packet of information at the application layer is called |
| A. | packet |
| B. | message |
| C. | segment |
| D. | frame |
| Answer» B. message | |
| Explanation: for application, presentation and session layers there is no data format for message. message is message as such in these three layers. but when it comes to transport, network, data and physical layer they have data in format of segments, packets, frames and bits respectively. | |
| 242. | Which one of the following is an architecture paradigms? |
| A. | peer to peer |
| B. | client-server |
| C. | http |
| D. | both peer-to-peer & client-server |
| Answer» D. both peer-to-peer & client-server | |
| Explanation: http is a protocol. | |
| 243. | Application layer offers service. |
| A. | end to end |
| B. | process to process |
| C. | both end to end and process to process |
| D. | none of the mentioned |
| Answer» A. end to end | |
| Explanation: end to end service is provided in the application layer. whereas process to process service is provided at the transport layer. | |
| 244. | E-mail is |
| A. | loss-tolerant application |
| B. | bandwidth-sensitive application |
| C. | elastic application |
| D. | none of the mentioned |
| Answer» C. elastic application | |
| Explanation: because it can work with available throughput. | |
| 245. | Pick the odd one out. |
| A. | file transfer |
| B. | file download |
| C. | |
| D. | interactive games |
| Answer» D. interactive games | |
| Explanation: file transfer, file download and email are services provided by the application layer and there are message and data oriented. | |
| 246. | Which of the following is an application layer service? |
| A. | network virtual terminal |
| B. | file transfer, access, and management |
| C. | mail service |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: the services provided by the application layer are network virtual terminal, file transfer, access and management, mail services, directory services, various file and data operations. | |
| 247. | Which is a time-sensitive service? |
| A. | file transfer |
| B. | file download |
| C. | |
| D. | internet telephony |
| Answer» D. internet telephony | |
| Explanation: internet telephony is loss- tolerant other applications are not. | |
| 248. | Transport services available to applications in one or another form |
| A. | reliable data transfer |
| B. | timing |
| C. | security |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: the transport services that are provided to application are reliable data transfer, security and timing. these are very important for proper end to end services. | |
| 249. | Electronic mail uses which Application layer protocol? |
| A. | smtp |
| B. | http |
| C. | ftp |
| D. | sip |
| Answer» A. smtp | |
| Explanation: email uses various protocols like smtp, imap and pop. the most prominent one used in application layer is smtp. | |
| 251. | A remote object is an object whose method can be invoked from another virtual environment. | |
| A. | true | |
| B. | false | |
| C. | topic 5.2 client server programming | |
| Answer» A. true | ||
| Explanation: the statement is true. jvm is java virtual environment. rmi uses stub and skeleton object for communication with the remote object. a remote object is an object whose method can be invoked from another virtual environment. | ||
| 252. | A typical program creates some remote objects, makes references to these objects accessible, and waits for clients to invoke methods on these objects. |
| A. | server |
| B. | client |
| C. | thread |
| D. | concurrent |
| Answer» A. server | |
| Explanation: a server program creates remote objects. it gives reference to these objects and then waits for clients to invoke methods on these objects. | |
| 253. | A typical program obtains a remote reference to one or more remote objects on a server and then invokes methods on them. |
| A. | server |
| B. | client |
| C. | thread |
| D. | concurrent |
| Answer» B. client | |
| Explanation: a client program obtains a remote reference to one or more remote objects on a server. it then invokes methods on them. | |
| 254. | The layer, which provides the interface that client and server application objects use to interact with each other. |
| A. | increasing |
| B. | count |
| C. | bit |
| D. | stub/skeleton |
| Answer» D. stub/skeleton | |
| Explanation: the stub or skeleton layer | |
| 255. | A layer which is the binary data protocol layer. |
| A. | stub layer |
| B. | skeleton layer |
| C. | remote layer |
| D. | transport protocol |
| Answer» D. transport protocol | |
| Explanation: the transport protocol layer is the binary data protocol that sends remote object requests over the wire. a client is any remote application that communicates with these server objects. | |
| 256. | A middleware layer between the stub skeleton and transport. |
| A. | remote layer |
| B. | instruction layer |
| C. | reference layer |
| D. | remote reference layer |
| Answer» D. remote reference layer | |
| Explanation: the remote reference layer is the middleware between the stub/skeleton layer and underlying transport protocol. | |
| 257. | An object acting as a gateway for the client side. |
| A. | skeleton |
| B. | stub |
| C. | remote |
| D. | server |
| Answer» B. stub | |
| Explanation: the stub is an object that acts as a gateway for the client side. the outgoing requests are passed through the stub. | |
| 258. | A gateway for the server side object. |
| A. | skeleton |
| B. | stub |
| C. | remote |
| D. | server |
| Answer» A. skeleton | |
| Explanation: the skeleton is an object, acts as a gateway for the server side object. all the incoming requests are routed through it. | |
| 259. | RMI uses stub and skeleton for communication with the object. |
| A. | client |
| B. | remote |
| C. | server |
| D. | any |
| Answer» B. remote | |
| Explanation: rmi uses stub and skeleton object for communication with the remote object. a remote object is an object whose method can be invoked from another jvm. | |
| 260. | A piece of icon or image on a web page associated with another webpage is called |
| A. | url |
| B. | hyperlink |
| C. | plugin |
| D. | extension |
| Answer» B. hyperlink | |
| Explanation: urls are locators for resources present on the world wide web. a plugin provides extra functionality to the webpage. an extension provides modification allowance for the core functionality of a webpage. hyperlink is piece of icon or image on a web page associated with another webpage. | |
| 261. | Dynamic web page |
| A. | is same every time whenever it displays |
| B. | generates on demand by a program or a request from browser |
| C. | both is same every time whenever it displays and generates on demand by a program or a request from browser |
| D. | is different always in a predefined order |
| Answer» B. generates on demand by a program or a request from browser | |
| Explanation: a dynamic web page provides different content every time the user opens it based on some events like new additions or time of the day. languages such as javascript are used to respond to client-side events while languages such as php as used to respond to server-side events. | |
| 262. | What is a web browser? |
| A. | a program that can display a web page |
| B. | a program used to view html documents |
| C. | it enables user to access the resources of internet |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: a web browser is an application program that is used to access the world wide web resources, applications and websites. some examples of web browsers are google chrome, internet explorer and safari. | |
| 263. | Common gateway interface is used to |
| A. | generate executable files from web content by web server |
| B. | generate web pages |
| C. | stream videos |
| D. | download media files |
| Answer» A. generate executable files from web content by web server | |
| Explanation: cgi is an interface through servers can run execute console-based executable files on a web server that generates dynamic web pages. a cgi script executes only when a request is made. the script then generates html. | |
| 264. | URL stands for |
| A. | unique reference label |
| B. | uniform reference label |
| C. | uniform resource locator |
| D. | unique resource locator |
| Answer» C. uniform resource locator | |
| Explanation: the uniform resource locator | |
| 265. | A web cookie is a small piece of data that is |
| A. | sent from a website and stored in user’s web browser while a user is browsing a website |
| B. | sent from user and stored in the server while a user is browsing a website |
| C. | sent from root server to all servers |
| D. | sent from the root server to other root servers |
| Answer» A. sent from a website and stored in user’s web browser while a user is browsing a website | |
| Explanation: a web cookie is a small piece of data sent from a website and stored in user’s web browser while a user is browsing the website and is used to remember stateful information about the user’s operations on the website. this can help the website provide a better browsing experience to the user. | |
| 266. | Which one of the following is not used to generate dynamic web pages? |
| A. | php |
| B. | asp.net |
| C. | jsp |
| D. | css |
| Answer» D. css | |
| Explanation: css alone cannot be used to generate dynamic web pages as it does not provide many event handling functions. it can | |
| 267. | What is document object model (DOM)? |
| A. | convention for representing and interacting with objects in html documents |
| B. | application programming interface |
| C. | hierarchy of objects in asp.net |
| D. | scripting language |
| Answer» A. convention for representing and interacting with objects in html documents | |
| Explanation: dom is a hierarchical model | |
| 268. | AJAX stands for |
| A. | asynchronous javascript and xml |
| B. | advanced jsp and xml |
| C. | asynchronous jsp and xml |
| D. | advanced javascript and xml |
| Answer» A. asynchronous javascript and xml | |
| Explanation: ajax is a group of technologies that works on the client-side to create asynchronous web applications. it is used to modify only a part of a webpage and not the whole webpage whenever some event occurs. | |
| 269. | An alternative to JavaScript on windows platform is |
| A. | vbscript |
| B. | asp.net |
| C. | jsp |
| D. | php |
| Answer» A. vbscript | |
| Explanation: vbscript is a general-purpose, | |
| 270. | A DNS client is called |
| A. | dns updater |
| B. | dns resolver |
| C. | dns handler |
| D. | none of the mentioned |
| Answer» B. dns resolver | |
| Explanation: dns client also known as dns resolver also known as dns lookup helps to resolve dns requests using an external dns server. | |
| 271. | Servers handle requests for other domains |
| A. | directly |
| B. | by contacting remote dns server |
| C. | it is not possible |
| D. | none of the mentioned |
| Answer» B. by contacting remote dns server | |
| Explanation: whenever a request is received at server from other domains, it handles this situation by contacting remote dns server. | |
| 272. | DNS database contains |
| A. | name server records |
| B. | hostname-to-address records |
| C. | hostname aliases |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: domain name system not only deals with mapping ip addresses with the hostname but also deals with exchange of information in the server. | |
| 273. | If a server has no clue about where to find the address for a hostname then |
| A. | server asks to the root server |
| B. | server asks to its adjcent server |
| C. | request is not processed |
| D. | none of the mentioned |
| Answer» A. server asks to the root server | |
| Explanation: root name servers are actually very important and critical as they are the first step in translating human readable hostnames | |
| 274. | Which one of the following allows client to update their DNS entry as their IP address change? |
| A. | dynamic dns |
| B. | mail transfer agent |
| C. | authoritative name server |
| D. | none of the mentioned |
| Answer» A. dynamic dns | |
| Explanation: dynamic dns or in short ddns or dyndns helps in automatically updating a name server in the dns. this does not require manual editing. | |
| 276. | The right to use a domain name is delegated by domain name registers which are accredited by | |
| A. | internet architecture board | |
| B. | internet society | |
| C. | internet research task force | |
| D. | internet corporation for assigned names and numbers | |
| Answer» D. internet corporation for assigned names and numbers | ||
| Explanation: the icann (internet corporation for assigned names and numbers) deals with ip address space allocation, protocol identifier assignment, generic and country code top level domain name system management (gtld and cctld). | ||
| 277. | The domain name system is maintained by |
| A. | distributed database system |
| B. | a single server |
| C. | a single computer |
| D. | none of the mentioned |
| Answer» A. distributed database system | |
| Explanation: a domain name system is maintained by a distributed database system. it is a collection of multiple, logically interrelated databases distributed over a computer network. | |
| 278. | Which one of the following is not true? |
| A. | multiple hostnames may correspond to a single ip address |
| B. | a single hostname may correspond to many ip addresses |
| C. | a single hostname may correspond to a single ip address |
| D. | none of the mentioned |
| Answer» C. a single hostname may correspond to a single ip address | |
| Explanation: it need not be that a single hostname will correspond to a ip address. for example facebook.com and fb.com both correspond to same ip address. so there can be multiple hostnames for a single ip address. | |
| 279. | Simple mail transfer protocol (SMTP) utilizes as the transport layer protocol for electronic mail transfer. |
| A. | tcp |
| B. | udp |
| C. | dccp |
| D. | sctp |
| Answer» A. tcp | |
| Explanation: since tcp is a reliable protocol, it’s more efficient to use tcp protocol for e-mail transfer. tcp also provides more security than other transport layer protocols. | |
| 280. | SMTP connections secured by SSL are known as |
| A. | smtps |
| B. | ssmtp |
| C. | snmp |
| D. | starttls |
| Answer» A. smtps | |
| Explanation: ssmtp is a simple mail transfer program to send mail from a local pc to a mail host. snmp is a network management protocol. starttls connections are secured by tls. | |
| 281. | SMTP uses which of the following TCP port? |
| A. | 22 |
| B. | 23 |
| C. | 21 |
| D. | 25 |
| Answer» D. 25 | |
| Explanation: port 21 is used for ftp control connection, port 22 is used by ssh, and port 23 is used by telnet. | |
| 282. | Which one of the following protocol is used to receive mail messages? |
| A. | smtp |
| B. | post office protocol (pop) |
| C. | internet message access protocol (imap) |
| D. | ftp |
| Answer» D. ftp | |
| Explanation: ftp is used to share files. smtp, pop and imap are the protocols used to send and receive mails on the internet. | |
| 283. | What is on-demand mail relay (ODMR)? |
| A. | protocol for smtp security |
| B. | an smtp extension |
| C. | protocol for web pages |
| D. | protocol for faster mail transfer |
| Answer» B. an smtp extension | |
| Explanation: odmr is an extension to smtp, in which mails are relayed to the receivers after they are authenticated. it | |
| 284. | An SMTP session may not include |
| A. | zero smtp transaction |
| B. | one smtp transaction |
| C. | more than one smtp transaction |
| D. | one http transaction |
| Answer» D. one http transaction | |
| Explanation: an smtp session can only include smtp transactions regardless the number. any other protocol’s transaction is not included in an smtp session. | |
| 285. | SMTP defines |
| A. | message transport |
| B. | message encryption |
| C. | message content |
| D. | message password |
| Answer» A. message transport | |
| Explanation: as the name suggests, simple mail transfer protocol is only responsible for “how” the message is transferred i.e. | |
| 286. | Which layer is responsible for process-to- process delivery? |
| A. | physical layer |
| B. | network layer |
| C. | transport layer |
| D. | application layer |
| Answer» C. transport layer | |
| Explanation: the transport layer is responsible for process-to-process delivery, error control and flow control. it provides an interface for the implementation of process to process delivery through ports. there are 65,535 port numbers. | |
| 287. | 6 INTRODUCTION TO PEER TO PEER NETWORKS |
| A. | client/server |
| B. | source/destination |
| C. | message transfer |
| D. | peer to peer |
| Answer» A. client/server | |
| Explanation: the most common method used for this communication is client/server. the client requests a service through a particular port number to the port of the server using its socket address. then the server responds by giving the requested service to the client port. | |
| 288. | Multiple processes on destinations at transport layer are identified by |
| A. | mac address |
| B. | port number |
| C. | host number |
| D. | host address |
| Answer» B. port number | |
| Explanation: multiple processes on destinations are identified by a transport layer address also called as port number. the ip address along with the port number is called the socket address. | |
| 289. | According to Internet Assigned Numbers Authority (IANA), which of the following ranges is not a part of port number ranges? |
| A. | well-known ports |
| B. | registered ports |
| C. | dynamic ports |
| D. | static ports |
| Answer» D. static ports | |
| Explanation: iana divided port numbers into three ranges i.e., well-known, registered and dynamic ports. well-known port numbers range from 0 to 1023, registered port numbers are from 1024 to 49151 and dynamic port numbers are from 49152 to 65535. | |
| 290. | The combination of an IP address and port number is called as |
| A. | socket address |
| B. | port address |
| C. | mac address |
| D. | host address |
| Answer» A. socket address | |
| Explanation: socket address is the combination of an ip address and a port number and it is used to define the client-end and server-end processes uniquely. | |
| 291. | Which of the following is false with respect to Connectionless service of transport layer protocol? |
| A. | packets are not numbered |
| B. | packets are not delayed |
| C. | no acknowledgement |
| D. | packet may arrive out of sequence |
| Answer» B. packets are not delayed | |
| Explanation: there is a high probability in connectionless services like udp that the packet gets delayed or lost because there is no connection made between the two end nodes. no connection means that there is no unique pathway for the packets to travel. | |
| 292. | In transport layer, Multiplexing is done at |
| A. | channel |
| B. | receiver site |
| C. | sender site |
| D. | packet |
| Answer» C. sender site | |
| Explanation: at the sender’s side, there are multiple processes which may want to send packets. but there is only one transport layer protocol like tcp or udp working at a time. so the transport layer protocol gets the messages from these processes and separates them with different port numbers. this process is called multiplexing and it is done before sending packets to the receivers side. | |
| 293. | The process of error checking and dropping of the header, delivering messages to appropriate process based on port number is called as |
| A. | delivery of packets |
| B. | error correction |
| C. | multiplexing |
| D. | demultiplexing |
| Answer» D. demultiplexing | |
| Explanation: demultiplexing is the process of error checking and dropping of the header, delivering messages to appropriate process based on port number. the transport layer does this on the receiver’s end after the packet is received and takes help of the header attached by the sender’s side transport layer during multiplexing. | |
| 294. | Number of phases in the handshaking protocol? |
| A. | 2 |
| B. | 3 |
| C. | 4 |
| D. | 5 |
| Answer» C. 4 | |
| Explanation: there are 4 phases in the handshaking protocol. these are – | |
| 295. | In the SSL record protocol operation pad_2 is – |
| A. | is the byte 0x36 repeated 40 times for md5 |
| B. | is the byte 0x5c repeated 48 times for md5 |
| C. | is the byte 0x5c repeated 48 times for sha-1 |
| D. | is the byte 0x36 repeated 48 times for md5 |
| Answer» B. is the byte 0x5c repeated 48 times for md5 | |
| Explanation: pad_2 = is the byte 0x5c repeated 48 times for md5. | |
| 296. | In the SSL record protocol operation pad_1 is – |
| A. | is the byte 0x36 repeated 40 times for md5 |
| B. | is the byte 0x5c repeated 40 times for md5 |
| C. | is the byte 0x5c repeated 48 times for sha-1 |
| D. | is the byte 0x36 repeated 48 times for md5 |
| Answer» D. is the byte 0x36 repeated 48 times for md5 | |
| Explanation: pad_1 = is the byte 0x36 repeated 48 times for md5. | |
| 297. | In the Handshake protocol action, which is the last step of the Phase 2 : Server Authentication and Key Exchange? |
| A. | server_done |
| B. | server_key_exchange |
| C. | certificate_request |
| D. | crtificate_verify |
| Answer» A. server_done | |
| Explanation: the last step of the phase 2 is the server_done step. | |
| 298. | Which is the key exchange algorithm used in CipherSuite parameter? |
| A. | rsa |
| B. | fixed diffie-hellman |
| C. | ephemeral diffie-hellman |
| D. | any of the mentioned |
| Answer» D. any of the mentioned | |
| Explanation: we can use either of the following for the ciphersuite key exchange- | |
| 299. | The certificate message is required for any agreed-on key exchange method except |
| A. | ephemeral diffie-hellman |
| B. | anonymous diffie-hellman |
| C. | fixed diffie-hellman |
| D. | rsa |
| Answer» B. anonymous diffie-hellman | |
| Explanation: the certificate message is required for any agreed-on key exchange method except anonymous diffie-hellman. | |
| 301. | The DSS signature uses which hash algorithm? |
| A. | md5 |
| B. | sha-2 |
| C. | sha-1 |
| D. | does not use hash algorithm |
| Answer» C. sha-1 | |
| Explanation: the dss signature uses sha- 1. | |
| 302. | The RSA signature uses which hash algorithm? |
| A. | md5 |
| B. | sha-1 |
| C. | md5 and sha-1 |
| D. | none of the mentioned. |
| Answer» C. md5 and sha-1 | |
| Explanation: the md5 and sha-1 hash is concatenated together and the then encrypted with the server’s private key. | |
| 303. | What is the size of the RSA signature hash after the MD5 and SHA-1 processing? |
| A. | 42 bytes |
| B. | 32 bytes |
| C. | 36 bytes |
| D. | 48 bytes |
| Answer» C. 36 bytes | |
| Explanation: the size is 36 bytes after md5 and sha-1 processing. | |
| 304. | The certificate_request massage includes two parameters, one of which is- |
| A. | certificate_extension |
| B. | certificate_creation |
| C. | certificate_exchange |
| D. | certificate_type |
| Answer» D. certificate_type | |
| Explanation: the certificate_request massage includes two parameters : certificate_type and certificate_authorities. | |
| 305. | The client_key_exchange message uses a pre master key of size – |
| A. | 48 bytes |
| B. | 56 bytes |
| C. | 64 bytes |
| D. | 32 bytes |
| Answer» A. 48 bytes | |
| Explanation: the client_key_exchange message uses a pre master key of size 48 bytes. | |
| 306. | In the handshake protocol which is the message type first sent between client and server ? |
| A. | server_hello |
| B. | client_hello |
| C. | hello_request |
| D. | certificate_request |
| Answer» B. client_hello | |
| Explanation: interaction between the client and server starts via the client_hello message. | |
| 307. | Network layer firewall works as a |
| A. | frame filter |
| B. | packet filter |
| C. | content filter |
| D. | virus filter |
| Answer» B. packet filter | |
| Explanation: as you know, firewalls are available as hardware appliances, as software- only, or a combination of the two. in every case, the purpose of a firewall is to isolate your trusted internal network (or your personal pc) from the dangers of unknown resources on the internet and other network connections that may be harmful. the firewall prevents unauthorized access to your internal, trusted network from outside threats. | |
| 308. | Network layer firewall has two sub- categories as |
| A. | state full firewall and stateless firewall |
| B. | bit oriented firewall and byte oriented firewall |
| C. | frame firewall and packet firewall |
| D. | network layer firewall and session layer firewall |
| Answer» A. state full firewall and stateless firewall | |
| Explanation: most network layer firewalls can operate as stateful or stateless firewalls, creating two subcategories of the standard network layer firewall. stateful firewalls have the advantage of being able to track packets over a period of time for greater analysis and accuracy — but they require more memory and operate more slowly. stateless firewalls do not analyze past traffic and can be useful for systems where speed is more important than security, or for systems that have very specific and limited needs. for example, a computer that only needs to connect to a particular backup server does not need the extra security of a stateful firewall. | |
| 309. | A firewall is installed at the point where the secure internal network and untrusted external network meet which is also known as |
| A. | chock point |
| B. | meeting point |
| C. | firewall point |
| D. | secure point |
| Answer» A. chock point | |
| Explanation: a firewall can be a pc, a router, a midrange, a mainframe, a unix workstation, or a combination of these that determines which information or services can be accessed from the outside and who is permitted to use the information and services from outside. generally, a firewall is installed at the point where the secure internal network and untrusted external network meet, which is also known as a chokepoint. | |
| 310. | Which of the following is / are the types of firewall? |
| A. | packet filtering firewall |
| B. | dual homed gateway firewall |
| C. | screen host firewall |
| D. | dual host firewall |
| Answer» A. packet filtering firewall | |
| Explanation: a firewall can be a pc, a midrange, a mainframe, a unix workstation, a router, or combination of these. depending on the requirements, a firewall can consist of one or more of the following functional components: packet-filtering router | |
| 311. | A proxy firewall filters at |
| A. | physical layer |
| B. | data link layer |
| C. | network layer |
| D. | application layer |
| Answer» D. application layer | |
| Explanation: the application firewall is typically built to control all network traffic on any layer up to the application layer. it is able to control applications or services specifically, unlike a stateful network | |
| 312. | A packet filter firewall filters at |
| A. | physical layer |
| B. | data link layer |
| C. | network layer or transport layer |
| D. | application layer |
| Answer» C. network layer or transport layer | |
| Explanation: in computing, a firewall is a network security system that monitors and controls the incoming and outgoing network traffic based on predetermined security rules. | |
| 313. | What is one advantage of setting up a DMZ with two firewalls? |
| A. | you can control where traffic goes in three networks |
| B. | you can do stateful packet filtering |
| C. | you can do load balancing |
| D. | improved network performance |
| Answer» C. you can do load balancing | |
| Explanation: dmz stands for de-militarized zone. in a topology with a single firewall serving both internal and external users (lan and wan), it acts as a shared resource for these two zones. so load balancing can be done by adding another firewall. | |
| 314. | A firewall needs to be so that it can grow proportionally with the network that it protects. |
| A. | robust |
| B. | expansive |
| C. | fast |
| D. | scalable |
| Answer» B. expansive | |
| Explanation: the firewall has to be expansive because a network is expected to grow with time and if the firewall is unable to grow with it, the firewall won’t be able to handle the growing network traffic flow and will hence fail. | |
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