200 Câu trắc nghiệm 252 - On thi giua ky.pdf

Câu 1: The IETF standards documents are called ________ a) RFC b) RCF c) ID d) DFC Answer: a Explanation: RFC stands for Request For Comments and they are documents that describe methods, behaviors, research, or innovations applicable to the working of the Internet. Câu 2: In the layer hierarchy as the data packet moves from the upper to the lower layers, headers are ___________ a) Added b) Removed c) Rearranged d) Modified Answer: a Explanation: Each layer adds its own header to the packet from the previous layer. For example, in the Internet layer, the IP header is added over the TCP header on the data packet that came from the transport layer. Câu 3: The structure or format of data is called ___________ a) Syntax b) Semantics c) Struct d) Formatting Answer: a Explanation: The structure and format of data are defined using syntax. Semantics defines how a particular pattern to be interpreted, and what action is to be taken based on that interpretation. In programming languages, syntax of the instructions plays a vital role in designing of the program. Subscribe Now: Computer Network Newsletter | Important Subjects Newsletters advertisement Câu 4: Communication between a computer and a keyboard involves ______________ transmission. a) Automatic b) Half-duplex c) Full-duplex d) Simplex Answer: d Explanation: In simplex transmission, data flows in single direction which in this case refers to the data flowing from the keyboard to the computer. Another example would be of the mouse where the data flows from the mouse to the computer only. Câu 5: The first Network was called ________ a) CNNET b) NSFNET c) ASAPNET d) ARPANET Answer: d Explanation: ARPANET stands for Advanced Research Projects Agency Networks. It was the first network to be implemented which used the TCP/IP protocol in the year 1969. Get Free Certificate of Merit in Computer Networks Now! Câu 6: A _______ is the physical path over which a message travels. a) Path b) Medium c) Protocol d) Route Answer: b Explanation: Messages travel from sender to receiver via a physical path called the medium using a set of methods/rules called protocol. Mediums can be guided (wired) or unguided (wireless). Câu 7: Which organization has authority over interstate and international commerce in the communications field? a) ITU-T b) IEEE c) FCC d) ISOC Answer: c Explanation: FCC is the abbreviation for Federal Communications Commission. FCC is responsible for regulating all interstate communications originating or terminating in USA. It was founded in the year 1934. Câu 8: Which of this is not a network edge device? a) PC b) Smartphones c) Servers d) Switch Answer: d Explanation: Network edge devices refer to host systems, which can host applications like web browser. A switch can’t operate as a host, but as a central device which can be used to manage network communication. Câu 9: A _________ set of rules that governs data communication. a) Protocols b) Standards c) RFCs d) Servers Answer: a Explanation: In communications, a protocol refers to a set of rules and regulations that allow a network of nodes to transmit and receive information. Each layer in the network model has a protocol set, for example, the transport layer has TCP and UDP protocols. Câu 10: Three or more devices share a link in ________ connection. a) Unipoint b) Multipoint c) Point to point d) Simplex Answer: b Explanation: A multipoint communication is established when three or many network nodes are connected to each other. Frame relay, Ethernet and ATM are some examples of multipoint connections. This set of Computer Networks Multiple Choice Questions & Answers (MCQs) focuses on “Basics – 2”. Câu 11: 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 Explanation: A Computer network is defined as a collection of interconnected computers which uses a single technology for connection. A.distributed system is also the same as computer network but the main difference is that the whole collection of computers appears to its users as a single coherent system. Example:- World wide web Câu 12: 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 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. Câu 13: 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 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). Sanfoundry Certification Contest of the Month is Live. 100+ Subjects. Participate Now! advertisement Câu 14: 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 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. Câu 15: 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 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. Check this: Computer Science MCQs | MCA MCQs Câu 16: Bluetooth is an example of __________ a) personal area network b) local area network c) virtual private network d) wide area network Answer: a 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. Câu 17: 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 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. Câu 18: 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 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. Câu 19: 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 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. Câu 20: 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 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. Câu 21: Which of this is not a constituent of residential telephone line? a) A high-speed downstream channel b) A medium-speed downstream channel c) A low-speed downstream channel d) An ultra-high speed downstream channel Answer: c Explanation: A low-speed downstream channel is not a constituent of a residential telephone line. But it might be just a two-way telephone channel. Internet can be provided through a high-speed downstream channel in a residential telephone line. Câu 22: DSL telcos provide which of the following services? a) Wired phone access b) ISP c) Wired phone access and ISP d) Network routing and ISP Answer: c Explanation: DSL stands for Digital Subscriber Line and ISP stands for Internet Service Provider. In a Digital Subscriber Line system, the same company which provides phone connection is also an ISP. The internet is provided through the pre-installed telephone lines. Câu 23: The function of DSLAM is to __________ a) Convert analog signals into digital signals b) Convert digital signals into analog signals c) Amplify digital signals d) De-amplify digital signals Answer: a Explanation: DSLAM stands for Digital Subscriber Line Access Multiplexer and it’s used by Telcos to convert the analog signals to digital signals for the purpose of providing internet. The DSLAM located in a telco’s Central Office does this function. Sanfoundry Certification Contest of the Month is Live. 100+ Subjects. Participate Now! advertisement Câu 24: Which of the following terms is not associated with DSL? a) DSLAM b) CO c) Splitter d) CMTS Answer: d Explanation: CMTS stands for Cable modem termination system. It is used in cable internet access. In cable internet access, internet is not provided through telephone lines and the companies that provide such connections don’t necessarily provide telephone access. Câu 25: HFC contains _______ a) Fibre cable b) Coaxial cable c) A combination of Fibre cable and Coaxial cable d) Twisted Pair Cable Answer: c Explanation: Hybrid fiber-coaxial (HFC) is a telecommunications industry term for a broadband network that combines optical fiber and coaxial cable. It has been popularly used since the early 1990s. It is stronger than the optical fiber cables and faster than the co-axial cables. Check this: Computer Science MCQs | Computer Network Books Câu 26: Which of the following statements is not applicable for cable internet access? a) It is a shared broadcast medium b) It includes HFCs c) Cable modem connects home PC to Ethernet port d) Analog signal is converted to digital signal in DSLAM Answer: d Explanation: CMTS stands for Cable modem termination system. In cable access analog signal is converted to digital signal by CMTS. In cable internet access, internet is not provided through telephone lines. DSLAM is used by Telecom companies. Câu 27: Among the optical-distribution architectures that are essentially switched ethernet is __________ a) AON b) PON c) NON d) MON Answer:a Explanation: AON stands for Active optical networks which are essentially switched Ethernets. Each user has his/her own dedicated optical fiber line connecting to the ISP in an AON. Câu 28: StarBand provides __________ a) FTTH internet access b) Cable access c) Telephone access d) Satellite access Answer: d Explanation: StarBand was a two-way satellite broadband Internet service available in the U.S. from 2000–2015. It was discontinued from September 30 2015 due to increasing competition from other ISPs. Câu 29: Home Access is provided by __________ a) DSL b) FTTP c) Cable d) All of the mentioned Answer: d Explanation: Home Internet Access is provided by DSL, FTTP, and Cable. FTTP provides the fastest speeds followed by the cable connections and then the DSLs. FTTP is popularly used in modern connections. Câu 30: ONT is connected to splitter using _________ a) High speed fibre cable b) HFC c) Optical cable d) Twisted pair cable Answer: c Explanation: ONT stands for Optical Network Terminal. The ONT connects to the Termination Point (TP) with an optical fibre cable. It translates light signals from the fibre optic line to electric signals that the router can read. Câu 31: Which of the following factors affect transmission rate in DSL? a) The gauge of the twisted-pair line b) Degree of electrical interfernece c) Shadow fading d) The gauge of the twisted-pair line and degree of electrical interference Answer: d Explanation: Because DSL is made of twisted wire copper pair, the gauge of twisted pair line i.e. the protection and electrical interference would affect the transmission rate in DSL. Unlike DSL, FTTP is not really affected by these factors. Câu 32: How many layers are present in the Internet protocol stack (TCP/IP model)? a) 5 b) 7 c) 6 d) 10 Answer: a Explanation: There are five layers in the Internet Protocol stack. The five layers in Internet Protocol stack is Application, Transport, Network, Data link and Physical layer. The internet protocol stack model is also called the TCP/IP model and it’s used in modern Internet Communication. Câu 33: The number of layers in ISO OSI reference model is __________ a) 5 b) 7 c) 6 d) 10 Answer: b Explanation: The seven layers in ISO OSI reference model is Application, Presentation, Session, Transport, Network, Data link and Physical layer. OSI stands for Open System Interconnect and it is a generalized model. Câu 34: Which of the following layers is an addition to OSI model when compared with TCP IP model? a) Application layer b) Presentation layer c) Session layer d) Session and Presentation layer Answer: d Explanation: The only difference between OSI model and TCP/IP model is that the functions of Presentation and Session layer in the OSI model are handled by the transport layer itself in TCP/IP. OSI is a generalized model and TCP/IP is an application specific model. Note: Join free Sanfoundry classes at Telegram or Youtube advertisement Câu 35: Application layer is implemented in ____________ a) End system b) NIC c) Ethernet d) Packet transport Answer: a Explanation: Not only application layer, but presentation layer, session layer and transport layer are also implemented in the end system. The layers below are implemented outside the end system, for example, the network layer is implemented on the routers and the physical layer is implemented for the medium. Câu 36: Transport layer is implemented in ______________ a) End system b) NIC c) Ethernet d) Signal transmission Answer: a Explanation: Application, Presentation, Session and Transport layer are implemented in the end system. The transport layer handles the process to process delivery of the packet through ports. Take Computer Networks Practice Tests - Chapterwise! Câu 37: The functionalities of the presentation layer include ____________ a) Data compression b) Data encryption c) Data description d) All of the mentioned Answer: d Explanation: Some functions of the presentation layer include character-code translation, data conversion, data encryption and decryption, and data translation. It connects the application layer with the layers below converting the human readable text and media to machine readable format and vice-versa. Câu 38: Delimiting and synchronization of data exchange is provided by __________ a) Application layer b) Session layer c) Transport layer d) Link layer Answer: b Explanation: The session layer provides the mechanism for opening, closing and managing a session between end-user application processes. The session layer 5 is responsible for establishing managing synchronizing and terminating sessions. In TCP/IP protocol stack, the functions of the session layer are handled by the transport layer itself and thus the session layer is missing from the TCP/IP model. Câu 39: In OSI model, when data is sent from device A to device B, the 5th layer to receive data at B is _________ a) Application layer b) Transport layer c) Link layer d) Session layer Answer: d Explanation: In OSI reference model, the fifth layer is Session layer. Session layer provides the mechanism for opening, closing and managing a session between end-user application processes. In TCP/IP protocol stack, the functions of the session layer are handled by the transport layer itself and thus the session layer is missing from the TCP/IP model. Câu 40: In TCP IP Model, when data is sent from device A to device B, the 5th layer to receive data at B is ____________ a) Application layer b) Transport layer c) Link layer d) Session layer Answer: a Explanation: In TCP/IP model, the fifth layer is application layer. When data is sent from device A to device B, the 5th layer to receive data at B is application layer. Application layer provides the interface between applications and the network. The user interacts with only this layer. Câu 41: In the OSI model, as a data packet moves from the lower to the upper layers, headers are _______ a) Added b) Removed c) Rearranged d) Randomized Answer: b Explanation: In OSI reference model, when data packet moves from lower layers to higher layer, headers get removed. Whereas when the data packet moves from higher layer to lower layers, headers are added. These headers contain the essential control information for the protocols used on the specific layer. Câu 42: Which of the following statements can be associated with OSI model? a) A structured way to discuss and easier update system components b) One layer may duplicate lower layer functionality c) Functionality at one layer no way requires information from another layer d) It is an application specific network model Answer: c Explanation: One layer may use the information from another layer, for example timestamp value. The information is contained in the header inserted by the previous layer. The headers are added as the packet moves from higher layers to the lower layers. Câu 43: OSI stands for __________ a) open system interconnection b) operating system interface c) optical service implementation d) open service Internet Answer: a Explanation: OSI is the abbreviation for Open System Interconnection. OSI model provides a structured plan on how applications communicate over a network, which also helps us to have a structured plan for troubleshooting. It is recognized by the ISO as the generalized model for computer network i.e. it can be modified to design any kind of computer network. Câu 44: The number of layers in ISO OSI reference model is __________ a) 4 b) 5 c) 6 d) 7 Answer: d Explanation: In OSI reference model, there are 7 layers namely Application, Presentation, Session, Transport, Network, Data Link and Physical layer. Each layer uses a protocol to perform its designated function, for example, the data link layer uses error detection protocols for error control functions. Câu 45: TCP/IP model does not have ______ layer but OSI model have this layer. a) session layer b) transport layer c) application layer d) network layer Answer: a Explanation: In OSI reference model, there are two layers which are not present in TCP/IP model. They are Presentation and Session layer. The functions of Presentation and Session layer in the OSI model are handled by the transport layer itself in TCP/IP. Sanfoundry Certification Contest of the Month is Live. 100+ Subjects. Participate Now! advertisement Câu 46: Which layer is used to link the network support layers and user support layers? a) session layer b) data link layer c) transport layer d) network layer Answer: c Explanation: Physical, data link and network layers are network support layers and session, presentation and application layers are user support layers. The transport layer links these layers by segmenting and rearranging the data. It uses protocols like TCP and UDP. Câu 47: Which address is used on the internet for employing the TCP/IP protocols? a) physical address and logical address b) port address c) specific address d) all of the mentioned Answer: d Explanation: The physical, logical, port and specific addresses are used in TCP/IP protocol. All the addressing schemes, that is physical (MAC) and logical address, port address and specific address are employed in both TCP/IP model and OSI model. In TCP/IP, the addresses are more focused on the internet implementation of these addresses. Check this: Computer Science MCQs | Computer Network Books Câu 48: TCP/IP model was developed _____ the OSI model. a) prior to b) after c) simultaneous to d) with no link to Answer: a Explanation: Several TCP/IP prototypes were developed at multiple research centers between 1978 and 1983, whereas OSI reference model was developed in the year 1984. TCP/IP was developed with the intention to create a model for the Internet while OSI was intended to be a general network model. Câu 49: Which layer is responsible for process to process delivery in a general network model? a) network layer b) transport layer c) session layer d) data link layer Answer: b Explanation: The role of Transport layer (Layer 4) is to establish a logical end to end connection between two systems in a network. The protocols used in Transport layer is TCP and UDP. The transport layer is responsible for segmentation of the data. It uses ports for the implementation of process-to-process delivery. Câu 50: Which address is used to identify a process on a host by the transport layer? a) physical address b) logical address c) port address d) specific address Answer: c Explanation: A port number is a way to identify a specific process to which an Internet or other network message is to be forwarded when it arrives at a server. Some examples of port numbers are port 20 which is used for FTP data, port 22 which is used for SSH remote login ,and port 23 which is used for TELNET. Câu 51: Which layer provides the services to user? a) application layer b) session layer c) presentation layer d) physical layer Answer: a Explanation: In networking, a user mainly interacts with application layer to create and send information to other computer or network. Application layer provides the interface between applications and the network. It is the top-most layer in both the TCP/IP and the OSI model. Câu 52: Transmission data rate is decided by ____________ a) network layer b) physical layer c) data link layer d) transport layer Answer: b Explanation: Physical layer is a layer 1 device which deals with network cables or the standards in use like connectors, pins, electric current used etc. Basically the transmission speed is determined by the cables and connectors used. Hence it is physical layer that determines the transmission speed in network. Some of the cables used for high speed data transmission are optical fiber cables and twisted pair cables. Câu 53: The physical layer is concerned with ___________ a) bit-by-bit delivery b) process to process delivery c) application to application delivery d) port to port delivery Answer: a Explanation: Physical layer deals with bit to bit delivery in networking. The data unit in the physical layer is bits. Process to process delivery or the port to port delivery is dealt in the transport layer. The various transmission mediums aid the physical layer in performing its functions. Câu 54: 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 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. Câu 55: 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 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. Subscribe Now: Computer Network Newsletter | Important Subjects Newsletters advertisement Câu 56: 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 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 handles which media connection the signal should be forwarded to physically. Câu 57: 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 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. Get Free Certificate of Merit in Computer Networks Now! Câu 58: 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 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. Câu 59: The physical layer is responsible for __________ a) line coding b) channel coding c) modulation d) all of the mentioned Answer: d Explanation: The physical layer is responsible for line coding, channel coding and modulation that is needed for the transmission of the information. The physical configuration including pins, connectors and the electric current used is dealt in the physical layer based on the requirement of the network application. Câu 60: 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 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. Câu 61: A single channel is shared by multiple signals by ____________ a) analog modulation b) digital modulation c) multiplexing d) phase modulation Answer: c 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. Câu 62: Wireless transmission of signals can be done via ___________ a) radio waves b) microwaves c) infrared d) all of the mentioned Answer: d 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. Câu 63: The data link layer takes the packets from _________ and encapsulates them into frames for transmission. a) network layer b) physical layer c) transport layer d) application layer Answer: a Explanation: In computer networks, the data from application layer is sent to transport layer and is converted to segments. These segments are then transferred to the network layer and these are called packets. These packets are then sent to data link layer where they are encapsulated into frames. These frames are then transferred to physical layer where the frames are converted to bits. Error control and flow control data is inserted in the frames at the data link layer. Câu 64: 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 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. Câu 65: 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 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. The MAC sublayer also prevents collision using protocols like CSMA/CD. Subscribe Now: Computer Network Newsletter | Important Subjects Newsletters advertisement Câu 66: Header of a frame generally contains ______________ a) synchronization bytes b) addresses c) frame identifier d) all of the mentioned Answer: d 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. Câu 67: 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 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. Become Top Ranker in Computer Networks Now! Câu 68: 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 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. Câu 69: CRC stands for __________ a) cyclic redundancy check b) code repeat check c) code redundancy check d) cyclic repeat check Answer: a 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. Câu 70: 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 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. Câu 71: 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 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. Câu 72: 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 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. Câu 73: Transport layer aggregates data from different applications into a single stream before passing it to ____________ a) network layer b) data link layer c) application layer d) physical layer Answer: a Explanation: The flow of data in the OSI model flows in following manner Application -> Presentation -> Session -> Transport -> Network -> Data Link -> Physical. Each and every layer has its own set of functions and protocols to ensure efficient network performance. Câu 74: Which of the following are transport layer protocols used in networking? a) TCP and FTP b) UDP and HTTP c) TCP and UDP d) HTTP and FTP Answer: c Explanation: Both TCP and UDP are transport layer protocol in networking. TCP is an abbreviation for Transmission Control Protocol and UDP is an abbreviation for User Datagram Protocol. TCP is connection oriented whereas UDP is connectionless. Câu 75: User datagram protocol is called connectionless because _____________ a) all UDP packets are treated independently by transport layer b) it sends data as a stream of related packets c) it is received in the same order as sent order d) it sends data very quickly Answer: a Explanation: UDP is an alternative for TCP and it is used for those purposes where speed matters most whereas loss of data is not a problem. UDP is connectionless whereas TCP is connection oriented. Note: Join free Sanfoundry classes at Telegram or Youtube advertisement Câu 76: Transmission control protocol ___________ a) is a connection-oriented protocol b) uses a three way handshake to establish a connection c) receives data from application as a single stream d) all of the mentioned Answer: d Explanation: TCP provides reliable and ordered delivery of a stream of bytes between hosts communicating via an IP network. Major internet applications like www, email, file transfer etc rely on TCP. TCP is connection oriented and it is optimized for accurate delivery rather than timely delivery. Câu 77: An endpoint of an inter-process communication flow across a computer network is called __________ a) socket b) pipe c) port d) machine Answer: a 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. Take Computer Networks Mock Tests - Chapterwise! Start the Test Now: Chapter 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 Câu 78: Socket-style API for windows is called ____________ a) wsock b) winsock c) wins d) sockwi Answer: b Explanation: Winsock is a programming interface which deals with input output requests for internet applications in windows OS. It defines how windows network software should access network services. Câu 79: 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 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. Câu 80: A _____ is a TCP name for a transport service access point. a) port b) pipe c) node d) protocol Answer: a Explanation: Just as the IP address identifies the computer, the network port identifies the application or service running on the computer. A port number is 16 bits. The combination of IP address preceded with the port number is called the socket address. Câu 81: Transport layer protocols deals with ____________ a) application to application communication b) process to process communication c) node to node communication d) man to man communication Answer: b Explanation: Transport layer is 4th layer in TCP/IP model and OSI reference model. It deals with logical communication between process. It is responsible for delivering a message between network host. Câu 82: 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 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. Câu 83: The network layer is concerned with __________ of data. a) bits b) frames c) packets d) bytes Answer: c Explanation: In computer networks, the data from the application layer is sent to the transport layer and is converted to segments. These segments are then transferred to the network layer and these are called packets. These packets are then sent to data link layer where they are encapsulated into frames. These frames are then transferred to physical layer where the frames are converted to bits. Câu 84: 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 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. Câu 85: 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 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. Note: Join free Sanfoundry classes at Telegram or Youtube advertisement Câu 86: 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 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. Câu 87: 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 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. The routing algorithms go hand in hand with the operations of all the routers in the networks. The routers are the main participants in these algorithms. Take Computer Networks Tests Now! Câu 88: 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 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. Câu 89: 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 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. Câu 90: 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 Explanation: The Routing Information Protocol (RIP) is used by the network layer for the function of dynamic routing. Congestion control focuses on the flow of the traffic in the network and uses algorithms like traffic aware routing, admission control and load shedding to deal with congestion. Câu 91: The network layer protocol for internet is __________ a) ethernet b) internet protocol c) hypertext transfer protocol d) file transfer protocol Answer: b Explanation: There are several protocols used in Network layer. Some of them are IP, ICMP, CLNP, ARP, IPX, HRSP etc. Hypertext transfer protocol is for application layer and ethernet protocol is for data link layer. Câu 92: ICMP is primarily used for __________ a) error and diagnostic functions b) addressing c) forwarding d) routing Answer: a Explanation: ICMP abbreviation for Internet Control Message Protocol is used by networking devices to send error messages and operational information indicating a host or router cannot be reached. ICMP operates over the IP packet to provide error reporting functionality as IP by itself cannot report errors. Câu 93: Which is not a application layer protocol? a) HTTP b) SMTP c) FTP d) TCP Answer: d Explanation: TCP is transport layer protocol. Câu 94: The packet of information at the application layer is called __________ a) Packet b) Message c) Segment d) Frame Answer: b 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. Câu 95: 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 Explanation: HTTP is a protocol. Sanfoundry Certification Contest of the Month is Live. 100+ Subjects. Participate Now! advertisement Câu 96: Application developer has permission to decide the following on transport layer side a) Transport layer protocol b) Maximum buffer size c) Both Transport layer protocol and Maximum buffer size d) None of the mentioned Answer: c Explanation: Application layer provides the interface between applications and the network. So application developer can decide what transport layer to use and what should be its maximum buffer size. Câu 97: 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 Explanation: End to End service is provided in the application layer. Whereas process to process service is provided at the transport layer. Check this: Computer Science MCQs | MCA MCQs Câu 98: E-mail is _________ a) Loss-tolerant application b) Bandwidth-sensitive application c) Elastic application d) None of the mentioned Answer: c Explanation: Because it can work with available throughput. Câu 99: Pick the odd one out. a) File transfer b) File download c) E-mail d) Interactive games Answer: d Explanation: File transfer, File download and Email are services provided by the application layer and there are message and data oriented. Câu 100: 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 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. Câu 101: To deliver a message to the correct application program running on a host, the _______ address must be consulted. a) IP b) MAC c) Port d) None of the mentioned Answer: c Explanation: IP address lets you know where the network is located. Whereas MAC address is a unique address for every device. Port address identifies a process or service you want to carry on. Câu 102: Which is a time-sensitive service? a) File transfer b) File download c) E-mail d) Internet telephony Answer: d Explanation: Internet telephony is Loss-tolerant other applications are not. Câu 103: 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 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. Câu 104: Electronic mail uses which Application layer protocol? a) SMTP b) HTTP c) FTP d) SIP Answer: a Explanation: Email uses various protocols like SMTP, IMAP and POP. The most prominent one used in application layer is SMTP. Câu 105: The entire hostname has a maximum of ___________ a) 255 characters b) 127 characters c) 63 characters d) 31 characters Answer: a Explanation: An entire hostname can have a maximum of 255 characters. Although each label must be from 1 to 63 characters long. Host name is actually a label that is given to a device in a network. Câu 106: A DNS client is called _________ a) DNS updater b) DNS resolver c) DNS handler d) none of the mentioned Answer: b Explanation: DNS client also known as DNS resolver also known as DNS lookup helps to resolve DNS requests using an external DNS server. Câu 107: 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 Explanation: Whenever a request is received at server from other domains, it handles this situation by contacting remote DNS server. Sanfoundry Certification Contest of the Month is Live. 100+ Subjects. Participate Now! advertisement Câu 108: DNS database contains _______ a) name server records b) hostname-to-address records c) hostname aliases d) all of the mentioned Answer: d Explanation: Domain Name system not only deals with mapping IP addresses with the hostname but also deals with exchange of information in the server. Câu 109: 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 Explanation: Root name servers are actually very important and critical as they are the first step in translating human readable hostnames into IP addresses for carrying out communication. Check this: Computer Science MCQs | Computer Science Books Câu 110: 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 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. Câu 111: Wildcard domain names start with label _______ a) @ b) * c) & d) # Answer: b Explanation: A wildcard DNS record matches requests to a non existent domain name. This wildcard DNS record is specified by using asterisk “*” as the starting of a domain name. Câu 112: 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 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). Câu 113: 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 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. Câu 114: 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 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. Câu 115: 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 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. Câu 116: 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 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. Câu 117: 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 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. Subscribe Now: Computer Network Newsletter | Important Subjects Newsletters advertisement Câu 118: 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 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. Câu 119: URL stands for ________ a) unique reference label b) uniform reference label c) uniform resource locator d) unique resource locator Answer: c Explanation: The Uniform Resource Locator is a locator for the resource to be located by HTTP on the World Wide Web. The URL is derived from the Uniform Resource Identifier. Become Top Ranker in Computer Networks Now! Câu 120: 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 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. Câu 121: Which one of the following is not used to generate dynamic web pages? a) PHP b) ASP.NET c) JSP d) CSS Answer: d Explanation: CSS alone cannot be used to generate dynamic web pages as it does not provide many event handling functions. It can be used along with JavaScript to generate dynamic web pages which are visually compelling. Câu 122: An alternative to JavaScript on windows platform is _______ a) VBScript b) ASP.NET c) JSP d) PHP Answer: a Explanation: VBScript is a general-purpose, lightweight and active scripting language which can be used on Microsoft Visual Basic. It was first released in 1996. Câu 123: 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 Explanation: DOM is a hierarchical model i.e. a tree used to represent an HTML or XML document. Every node of the tree an object that represents a part of the document. Câu 124: The TTL field has value 10. How many routers (max) can process this datagram? a) 11 b) 5 c) 10 d) 1 Answer: c 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. Note: Join free Sanfoundry classes at Telegram or Youtube advertisement Câu 125: If the value in protocol field is 17, the transport layer protocol used is _____________ a) TCP b) UDP c) ICMP d) IGMP Answer: b 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. Câu 126: The data field cannot carry which of the following? a) TCP segment b) UDP segment c) ICMP messages d) SMTP messages Answer: c 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. Take Computer Networks Practice Tests - Chapterwise! Start the Test Now: Chapter 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 Câu 127: What should be the flag value to indicate the last fragment? a) 0 b) 1 c) TTl value d) Protocol field value Answer: a 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. Câu 128: 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 Explanation: IP does not provide reliable delivery service for the data. It’s dependent upon the transport layer protocols like TCP to offer reliability. Câu 129: 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 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. Câu 130: Which field helps to check rearrangement of the fragments? a) offset b) flag c) ttl d) identifer Answer: a 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). Câu 131: Which of these is not applicable for IP protocol? a) Connectionless b) Offer reliable service c) Offer unreliable service d) Does not offer error reporting Answer: b Explanation: IP does not provide reliable delivery service for the data. It’s dependent upon the transport layer protocols like TCP to offer reliability. Câu 132: 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 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. Câu 133: Which field helps to check rearrangement of the fragments? a) Offset b) Flag c) TTL d) Identifier Answer: a 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). Sanfoundry Certification Contest of the Month is Live. 100+ Subjects. Participate Now! advertisement Câu 134: In classless addressing, there are no classes but addresses are still granted in ______ a) IPs b) Blocks c) Codes d) Sizes Answer: b Explanation: In classless addressing, there are no classes but addresses are still granted in blocks. The total number of addresses in a block of classless IP addresses = 2(32 – CIDR_value). Câu 135: In IPv4 Addresses, classful addressing is replaced with ________ a) Classless Addressing b) Classful Addressing c) Classful Advertising d) Classless Advertising Answer: a Explanation: Classful addressing is replaced with classless addressing as a large ratio of the available addresses in a class in calssful addressing is wasted. In classless addressing, one can reserve the number of IP addresses required by modifying the CIDR value and make sure that not many addresses are wasted. Check this: Computer Science Books | Computer Science MCQs Câu 136: First address in a block is used as network address that represents the ________ a) Class Network b) Entity c) Organization d) Codes Answer: c Explanation: First address in a block is used as network address that represents the organization. The network address can be found by AND’ing any address in the block by the default mask. The last address in a block represents the broadcast address. Câu 137: In classful addressing, a large part of available addresses are ________ a) Organized b) Blocked c) Wasted d) Communicated Answer: c Explanation: In classful addressing, a large part of available addresses are wasted. Thus to solve this classful addressing is replaced with classless addressing where one can reserve the number of IP addresses required by modifying the CIDR value and make sure that not many addresses are wasted. Câu 138: Network addresses are a very important concept of ________ a) Routing b) Mask c) IP Addressing d) Classless Addressing Answer: c Explanation: Network addresses are a very important concept of IP addressing. The first address in a block is used as network address that represents the organization. The network address can be found by AND’ing any address in the block or class by the default mask. Câu 139: Which of this is not a class of IP address? a) Class E b) Class C c) Class D d) Class F Answer: d Explanation: Class F is not a class of IP addressing. There are only five classes of IP addresses: Class A (0.0.0.0 to 127.255.255.255), Class B (128.0.0.0 to 191.255.255.255), Class C (192.0.0.0 to 223.255.255.255), Class D (224.0.0.0 to 239.255.255.255), and Class E (240.0.0.0 to 255.255.255.255). Câu 140: A local telephone network is an example of a _______ network. a) Packet switched b) Circuit switched c) Bit switched d) Line switched Answer: b Explanation: Circuit switching is connection oriented switching technique, whereas in the case of packet switching, it is connectionless. Circuit switching is implemented in the Physical layer, whereas packet switching is implemented in the Network layer. Internet too is based on the concept of circuit switching. Câu 141: Most packet switches use this principle ____________ a) Stop and wait b) Store and forward c) Store and wait d) Stop and forward Answer: b 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. Câu 142: 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 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. Sanfoundry Certification Contest of the Month is Live. 100+ Subjects. Participate Now! advertisement Câu 143: 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 Explanation: Packet switching and Circuit switching are two different types of switching methods used to connect the multiple communicating devices with one another. Packet switching is used in conventional LAN systems and circuit switching is used in telephonic systems. Câu 144: 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 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. Check this: Computer Science Books | MCA MCQs Câu 145: 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 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. Câu 146: In _________ systems, resources are allocated on demand. a) packet switching b) circuit switching c) line switching d) frequency switching Answer: a 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. Câu 147: 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 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. Câu 148: _____________ allows LAN users to share computer programs and data. a) Communication server b) Print server c) File server d) Network Answer: c Explanation: A file server allows LAN users to share computer programs and data. It uses the File Transfer Protocol to provide this feature on ports 20 and 21. The file server works as a medium for the transfer. Câu 149: With respect to physical media, STP cables stands for _________ a) Shielded Twisted Pair Cable b) Spanning Tree Protocol Cable c) Static Transport Protocol Cable d) Shielded Two Power Cable Answer: a Explanation: For physical media, STP cable stands for Shielded twisted pair cable. 100 Mbps is the max data capacity of STP cable and its default connector is RJ45. It is popularly used in LANs due to its ease of maintenance and installation. Câu 150: A standalone program that has been modified to work on a LAN by including concurrency controls such as file and record locking is an example of ___________ a) LAN intrinsic software b) LAN aware software c) Groupware d) LAN ignorant software Answer: a Explanation: A standalone program that has been modified to work on a LAN by including concurrency controls such as file and record locking is an example of LAN intrinsic software. They are used to give better functionality of the program and the applications working over it to the users of the LAN. Subscribe Now: Computer Network Newsletter | Important Subjects Newsletters advertisement Câu 151: The __________ portion of LAN management software restricts access, records user activities and audit data, etc. a) Configuration management b) Security management c) Performance management d) Recovery management Answer: b Explanation: The Security management portion of LAN management software restricts access, records user activities, and audit data. It is responsible for controlling access to the network based on predefined policy. The security management ensures authentication, confidentiality, and integrity in the LAN. Câu 152: What is the max length of the Shielded twisted pair cable? a) 100 ft b) 200 ft c) 100 m d) 200 m Answer: c Explanation: The max the Shielded twisted pair cable is 100 meters. If the length exceeds 100 meters, the loss of signals flowing through the cable would be really high. Thus, STP cable is more suitable for smaller networks like LANs. Get Free Certificate of Merit in Computer Networks Now! 7. Which connector does the STP cable use? a) BNC b) RJ-11 c) RJ-45 d) RJ-69 Answer: c Explanation: RJ-45 is used for STP cable. 100 Mbps is the max data transfer rate that can be handled by STP. RJ-45 is popularly used to connect to modern-day routers, computer network cards, and other network devices. Câu 153: What is the central device in star topology? a) STP server b) Hub/switch c) PDC d) Router Answer: b Explanation: In star topology, no computer is connected to another computer directly but all the computers are connected to a central switch or hub. Every message sent from a source computer goes through the switch or hub and the switch or hub then forwards the message only to the intended destination computer. Câu 154: Which of the following architecture uses the CSMA/CD access method? a) ARC net b) Ethernet c) Router d) STP server Answer: b Explanation: Collision detection is not possible in Ethernet without extensions. Collision detection techniques for multiple access like CSMA/CD are used to detect collisions in the Ethernet architecture. Câu 155: 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 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. Câu 156: Novell’s implementation of RIP updates routing tables every _________ seconds. a) 60 b) 90 c) 10 d) 30 Answer: a 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. Câu 157: Open Shortest Path First (OSPF) is also called as _____________ a) Link state protocol b) Error-correction protocol c) Routing information protocol d) Border gateway protocol Answer: a Explanation: In OSPF, the link state of each path is checked, and then the shortest path is chosen among only the open state links. Each OSPF router monitors the cost of the link to each of its neighbors and then floods the link state information to other routers in the network. Câu 158: 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 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. Câu 159: Ethernet frame consists of ____________ a) MAC address b) IP address c) Default mask d) Network address Answer: a Explanation: The Ethernet frame has a header that contains the source and destination MAC address. Each MAC address is of 48 bits. Câu 160: What is start frame delimeter (SFD) in ethernet frame? a) 10101010 b) 10101011 c) 00000000 d) 11111111 Answer: b 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. Câu 161: MAC address is of ___________ a) 24 bits b) 36 bits c) 42 bits d) 48 bits Answer: d Explanation: MAC address is like a local address for the NIC that is used to make a local Ethernet (or wifi) network function. It is of 48 bits. Note: Join free Sanfoundry classes at Telegram or Youtube advertisement Câu 162: 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 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. 6. 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 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. Câu 163: High speed and long ethernet works on _________ a) coaxial cable b) twisted pair cable c) optical fiber d) unshielded twisted pair cable Answer: c 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. Câu 164: The maximum size of payload field in ethernet frame is __________ a) 1000 bytes b) 1200 bytes c) 1300 bytes d) 1500 bytes Answer: d 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. Câu 165: EIGRP is a routing protocol design by Cisco. a) True b) False Answer: a Explanation: EIGRP stands for Enhanced Interior Gateway Routing Protocol is a routing protocol designed by Cisco. It is available only on Cisco routers. Câu 166: Administrative distance for internal EIGRP is ______ a) 90 b) 170 c) 110 d) 91 Answer: a Explanation: Routers use the metric of administrative distance to select the best path when there are different routes to the same destination from two different routing protocols as it is a measure of reliability of routing protocols. Administrative distance for internal EIGRP is 90. Check this: Computer Science Books | Computer Network Books Câu 167: For default gateway, which of following commands will you use on a Cisco router? a) IP default network b) IP default gateway c) IP default route d) Default network Answer: a Explanation: IP default network command is used to find the default gateway in Cisco router. If the router finds routes to the node, it considers the routes to that node for installation as the gateway to it. Câu 168: Administrative distance for external EIGRP route is _______ a) 90 b) 170 c) 110 d) 100 Answer: b Explanation: Routers use the metric of administrative distance to select the best path when there are different routes to the same destination from two different routing protocols as it is a measure of reliability of routing protocols. Administrative distance for external EIGRP is 170. Câu 169: EIGRP uses the ____________ algorithm for finding shortest path. a) SPF b) DUAL c) Linkstat d) Djikstra’s Answer: b Explanation: EIGRP uses the DUAL algorithm for finding shortest path. DUAL stands for diffusing update algorithm and it is used to prevent routing loops by recalculating routes globally. Câu 170: In EIGRP best path is known as the successor, where as backup path is known as __________ a) Feasible successor b) Back-up route c) Default route d) There is no backup route in EIGRP Answer: a Explanation: Feasible successor is the backup path. The backup path is used alternatively used whenever the best path fails. It is not used primarily because it is comparatively expensive than the best path. Câu 171: DHCP (dynamic host configuration protocol) provides __________ to the client. a) IP address b) MAC address c) Url d) None of the mentioned Answer: a Explanation: We use DHCP to allow the hosts to acquire their ip addresses dynamically which is better than visiting each and every host on the network and configure all of this information manually. Câu 172: DHCP is used for ________ a) IPv6 b) IPv4 c) Both IPv6 and IPv4 d) None of the mentioned Answer: c Explanation: DHCP is used for both IPv4 and IPv6 addressing. With DHCP you get to let the hosts know about the change dynamically, and hosts update their info themselves. Câu 173: The DHCP server _________ a) maintains a database of available IP addresses b) maintains the information about client configuration parameters c) grants a IP address when receives a request from a client d) all of the mentioned Answer: d Explanation: Whenever a DHCP server gets a request from a client it responds with a DHCP offer containing IP address being offered, network mask offered, the amount of time that the client can use and keep it, the ip address of the DHCP server making this offer. Subscribe Now: Computer Network Newsletter | Important Subjects Newsletters advertisement Câu 174: IP assigned for a client by DHCP server is a) for a limited period b) for an unlimited period c) not time dependent d) none of the mentioned Answer: a Explanation: The IP address offered to a client is only for a limited period of time. There is actually a certain amount of time that the client can use and keep this IP address. Câu 175: DHCP uses UDP port _________ for sending data to the server. a) 66 b) 67 c) 68 d) 69 Answer: b Explanation: 67 is the UDP port number that is used as the destination port of a server. Whereas UDP port number 68 is used by the client. Participate in Computer Networks Certification Contest of the Month Now! Câu 176: The DHCP server can provide the _______ of the IP addresses. a) dynamic allocation b) automatic allocation c) static allocation d) all of the mentioned Answer: d Explanation: When a host acquires multiple offers of IP addresses from different DHCP servers, the host will broadcast a dhcp request identifying the server whose offer has been accepted. Câu 177: DHCP client and servers on the same subnet communicate via _________ a) UDP broadcast b) UDP unicast c) TCP broadcast d) TCP unicast Answer: a Explanation: DHCP actually employs a connectionless service, which is provided by UDP, since TCP is connection oriented. It is implemented with two UDP port numbers 67 and 68 for its operations. Câu 178: After obtaining the IP address, to prevent the IP conflict the client may use _________ a) internet relay chat b) broader gateway protocol c) address resolution protocol d) none of the mentioned Answer: c Explanation: ARP abbreviation for address resolution protocol is used for mapping IP addresses to MAC addresses that are present in the local network. Câu 179: What is DHCP snooping? a) techniques applied to ensure the security of an existing DHCP infrastructure b) encryption of the DHCP server requests c) algorithm for DHCP d) none of the mentioned Answer: a Explanation: DHCP snooping is a security feature that is used in OS of a network in the layer 2. This technology prevents unauthorized DHCP servers offering IP addresses to DHCP clients. Câu 180: If DHCP snooping is configured on a LAN switch, then clients having specific ______ can access the network. a) MAC address b) IP address c) Both MAC address and IP address d) None of the mentioned Answer: c Explanation: The DHCP snooping is done to prevent unauthorized IP addresses being offered by unauthorized servers. This features allows only specific mac addresses and IP addresses to access the network. Câu 181: You are creating a network for a small business with only four employees. Because employees often leave the office to visit clients, a minimum of one person is in the office and using a computer at any given time. Currently there are two computers in the office, but the company is willing to purchase more if needed. Based on this information, what is the minimum number of computers that you’ll need to create a network? A. One *B. Two C. Three D. Four Câu 182: A new intranet has been created in your organization, and includes an FTP site to download files and a news server for sharing information. The network is internetworked with a network belonging to a subsidiary of the company. The subsidiary’s network uses Apple computers, and uses AppleTalk as a network protocol. To access the intranet, which of the following protocols would need to be installed on your computer? A. IPX/SPX B. NWLink *C. TCP/IP D. AppleTalk Câu 183: The LAN used by your organization is on the single floor of a building. The network has servers and other resources that are kept in a secure server room. You are the only network administrator in the organization and have sole responsibility of managing these resources and administration of network security for all of the users who are distributed throughout the network. What type of network model is being used? *A. Centralized B. Decentralized C. Distributed D. Peer-to-Peer Câu 184: Your company’s network is on several floors of a building. Because of the amount of data being stored, there are three file servers, a Web server for the intranet, an e-mail server for internal e-mail, and a SQL server that is used for several databases that have been developed in house. Because of security reasons, floppy disks and other devices to transfer or transmit data to and from the computer have been removed and aren’t permitted. What type of network model is being used? *A. Client/Server B. Peer-to-Peer C. MAN D. PAN Câu 185: Your company’s network spans three buildings that are within a mile of one another. Three servers are kept in a secure server room in the building where your office is located, while each other building has a server that is locked in a closet. Users at each of these locations have been trained on how to replace the backup tapes in these servers and have the ability to give permissions for user accounts to print to specific printers in those locations. You solely control other aspects of security, inclusive to password requirements, and access to folders on these servers. What type of network model is being used? A. Centralized *B. Decentralized C. P2P D. Peer-to-Peer Câu 186: A company has hired you to create a network for their small business. Security isn’t an issue, and there isn’t enough money to hire or train a permanent network administrator. Users of the network routinely work on similar projects, and need to access one another’s data on a regular basis. What type of network model will you use? A. Client/Server *B. Peer-to-Peer C. Client D. Server Câu 187: A company has multiple offices that are internetworked. Office A has a single computer that has the ability to dial into the Internet, but isn’t connected to the other offices. Office B is in another part of the country from the other offices, but doesn’t have its network interconnected to the other offices. Office C and D are in separate states, but have a dedicated connection between them. Office C has 20 computers that access each other’s machines, and provide services and data to one another. Office D has 50 computers that log onto the network using a single server. Based on this information, which of the Offices are part of a LAN and a WAN? A. Office A and B B. Office B and C *C. Office C and D D. The entire network (Office A, B, C, and D) Câu 188: An organization has offices in two countries. Office A is a small field office with two networked computers and is internetworked with Office B that is across the road and has 10 networked computers. Because they are a subsidiary of the main company and perform different services from the rest of the organization, neither of these offices have been internetworked with the other offices, and is awaiting Internet connectivity to be provided next month. Office C is another field office that has a single computer, isn’t networked with other offices, and only has an Internet connection. Office D is the headquarters of the company, has 100 network users who are awaiting Internet connectivity to be added to the network, and has a network connection to Office E in London, which is their European office. Based on this information, which of the offices is connected to the largest WAN? A. Office A B. Office B *C. Office C D. Office D Câu 189: A company wants to create a LAN between two networks in different cities. To connect them, you want to have the fastest possible connection to meet their needs. Each network has massive amounts of data being sent between floors of their existing networked building, and you determine that at maximum, 1 Mbps of data will need to be transmitted during normal business hours. Although they are a large business, and cost is not a major issue, they don’t want to waste money on getting a solution with a bandwidth that’s higher than they need. What type of connection will you choose in connecting these networks? A. Dial-up modem B. ISDN *C. T1 D. T3 Câu 190: A company has several offices that are networked together across the city. Each of the sales representatives uses PDAs to keep track of appointments with clients. The company has just implemented a new system where the appointments taken by receptionists are automatically uploaded to the PDAs whenever the sales staff enters the main reception area. What types of networks are being used in this environment? Choose all that apply. *A. MAN B. SAN C. CAN *D. PAN Câu 191: You have been hired by a company that uses a topology shown in Figure 1.8. In looking at the physical layout of your network, which of the following types of topologies is being used? *A. Bus B. Star C. Mesh D. Ring Figure 1.8. Câu 192: You receive a call that the network is down. In this network, all of the computers are connected together using a single cable, which they are connected to using T-Connectors. Looking at the situation, you find that there is no break through the trunk. Which of the following is most likely the cause of the problem? A. A.failed network card. B. One of the computers is turned off. C. T-connectors are missing from the ends of the cable. *D. Terminators are missing from the ends of the cable. Câu 193: Your network uses cells to send and receive data to and from computers. This allows computers in different buildings to be networked together, so they can access data from servers in either building. A topology map has been created, using circles to identify the areas that computers can be placed to access the network. Based on this information, which of the following topologies is being used? A. Star B. Mesh *C. Wireless D. Ring Câu 194: You are training a new member of the IT Staff, and decide to explain the topology of the existing network, shown in the Figure 1.9. What topology is currently being used? A. Bus B. Star *C. Mesh D. Ring Figure 1.9. Câu 195: Your network has 10 computers that are networked together using a star topology. Which of the following is a possible point of failure for this topology, which could bring down the entire network? A. Cable B. Network card C. T-Connector *D. Switch Câu 196: You are the network administrator of a 10BaseT network. On the weekend, when few people are working, you run 110 m of cable to a new server that is being used as a file server. The cable is installed in a new section of the building, where no cabling currently exists. When you attempt to access files on the server, they are experiencing errors and corrupt data. Which of the following is most likely the cause of this problem? A. Bandwidth *B. Attenuation C. Crosstalk from a neighboring cable D. CSMA/CD issues Câu 197: Your company uses UTP cable for all of its network connections including workstations and servers. The users have reported problems connecting to one of the most important servers on the network and you have been called in to look at it, due to a possible physical security breach by a former employee. While examining the server, you find that a small battery-powered motor has been placed and is running next to the server’s network connection. What is causing the network problem? *A. Electromagnetic interference B. Static electricity C. Transceivers D. Unknown, but the motor is probably unrelated Câu 198: You are designing a new network and are concerned about interference from other wires. Which of the following is most susceptible to transmission errors due to crosstalk? A. Coaxial *B. UTP C. STP D. Fiber optic Câu 199: You are designing a new network for a grocery store. Cabling will have to run along the ceiling, where there are a significant number of florescent lights. You are concerned about interference from these lights. Which of the following cable types could be used, which would not be susceptible to this type of interference? A. Coaxial B. UTP C. STP *D. Fiber optic Câu 200: Your network uses vampire taps and AUI connectors to access data from the network cable. Which of the following cabling types is being used? A. Thinnet *B. Thicknet C. STP D. Fiber optic

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