COMPUTER NETWORKS Multiple Choice Questions :-
1. If a datagram router goes down then …………..
(A) all packets will suffer
(B) only those packets which are queued in the router at that time will suffer
(C) only those packets which are not queued in the router at that time will suffer
(D) no packets will suffer
Answer: B
2. In datagram subnet new route is chosen …………………
(A) for every packet sent
(B) for all the packet sent
(C) only for the first packet
(D) for the packet which is not transmitted
Answer: A
3. The PSTN is an example of a ………………… network.
(A) packet switched (B) circuit switched
(C) message switched (D) None of these
Answer: B
4. Each packet is routed independently in ……………….
(A) virtual circuit subnet (B) short circuit subnet
(C) datagram subnet (D) ATM subnet
Answer: C
5. For a connection oriented service, we need a ……………
(A) virtual circuit subnet (B) short circuit subnet
(C) datagram subnet (D) wireless subnet
Answer: C
6. Which type of switching uses the entire capacity of a dedicated link?
(A) circuit switching
(B) datagram packet switching
(C) virtual circuit packet switching
(D) message switching
Answer: D
7. In …………… circuit switching, delivery of data is delayed because data must be stored and retrieved from RAM.
(A) space division (B) time division
(C) virtual (D) None of these
Answer: B
8. In ……………., each packet of a message need not follow the same path from sender to receiver.
(A) circuit switching
(B) message switching
(C) virtual approach to packet switching
(D) datagram approach to packet switching
Answer: D
9. In ………………, each packet of a message follows the same path from sender to receiver.
(A) circuit switching
(B) message switching
(C) virtual approach to packet switching
(D) datagram approach to packet switching
Answer: A
10. A permanent virtual circuit involves ……………..
(A) Connection establishment (B) Data transfer
(C) Connection release (D) Connection check
Answer: B
11. The set of optimal routes from all sources to a given destination from a tree rooted to the destination is known as ……………..
(A) Binary tree (B) Sparse tree
(C) Sink tree (D) AVL tree
Answer: C
12. Adaptive routing algorithms get their information from ………….
(A) only from local environment
(B) only from adjacent routers
(C) from locally, adjacent, external routers
(D) only from external routers
Answer: C
13. If the route from I to J is computed in advance, off line, and downloaded to the routers when the network is booted is called as ……………….
(A) Dynamic routing (B) Session routing
(C) Temporary routing (D) Static routing
Answer: D
14. In Hierarchical routing for N router subnet, the optimal number of levels is …………..
(A) logN (B) log(N -1)
(C) lnN (D) ln(N-1)
Answer: C
15. The router algorithm takes the decision to changes the route when ……………..
(A) router changes
(B) topology changes
(C) user changes
(D) transmission time does not change
Answer: B
16. If route from router I to router J is computed on line based on the current statistics, then it is called as ………………..
(A) Dynamic routing (B) Session routing
(C) Temporary routing (D) None of these
Answer: A
17. If the subnet uses virtual circuits internally, routing decisions are made only when a new virtual circuit is being setup. This is called as……………..
(A) Session routing (B) Circuit routing
(C) Datagram routing (D) Forwarding
Answer: A
18. …………….. change their routing decisions to reflect changes in the topology.
(A) Nonadaptive algorithms
(B) Adaptive algorithms
(C) Static algorithms
(D) Recursive algorithms
Answer: B
19. If router J is on the optimal path from router I to router K, then the path from J to K along the same route is ………………
(A) does not exist (B) optimal
(C) maximum (D) constant
Answer: B
20. If router J is on the optimal path from router I to router K, then the optimal path from J to K also falls along the same route is known as ………………..
(A) Routing principle (B) Optimality principle
(C) Sink tree principle (D) Network principle
Answer: B
21. ……………. do not base their routing decisions on measurements or estimates of the current traffic and topology.
(A) Non adaptive algorithms
(B) Adaptive algorithms
(C) Static algorithms
(D) Recursive algorithms
Answer: A
22. The method of network routing where every possible path between transmitting and receiving DTE is used is called ……………
(A) Random Routing (B) Packet Flooding
(C) Directory Routing (D) Message Switching
Answer: B
23. In Hierarchical routing, the routers are divided into what is called as ……………..
(A) zones (B) Cells
(C) Regions (D) None of these
Answer: C
24. The regions in Hierarchical routing are grouped in to ……………..
(A) Clusters (B) Zones
(C) Blocks (D) Cells
Answer: A
25. The Clusters in Hierarchical routing are grouped in to ………………
(A) Clusters (B) Zones
(C) Blocks (D) Cells
Answer: B
26. If a router sends every incoming packet out only on those lines that are going approximately in the right direction is known as ……………..
(A) Random flooding (B) Static flooding
(C) Selective flooding (D) Early flooding
Answer: C
27. In shortest path routing algorithm, the path length is measured based on ……………..
(A) time delay (B) number of hops
(C) size of the routers (D) routing table
Answer: B
28. Flooding always choose the ………………..
(A) Shortest path (B) First path
(C) Last path (D) Largest path
Answer: A
29. In military applications where large number of routers may be blown to bits at any instant, we use ……………….
(A) Shortest path first (B) First come first serve
(C) Forwarding (D) Flooding
Answer: D
30. In distributed applications, it is sometimes necessary to update all the databases concurrently, we use …………………..
(A) Shortest path first
(B) First come first serve
(C) Forwarding
(D) Flooding
Answer: D
31. In multicast routing with spanning tree method, a network with n groups, each with an average of m members, for each group we require ………………..
(A) n pruned spanning trees must be stored for a total of mn trees
(B) m pruned spanning trees must be stored for a total of m trees
(C) n pruned spanning trees must be stored for a total of n trees
(D) m pruned spanning trees must be stored for a total of mn trees
Answer: D
32. To do multicast routing, each router computes a …………………
(A) Binary tree (B) AVL tree
(C) Spanning tree (D) None of these
Answer: C
33. A well -defined groups that are numerically large in size but small compared to the network as a whole are used in …………………..
(A) Unicast routing (B) Multicast routing
(C) Broadcast routing (D) Telecast routing
Answer: B
34. The processes that keep track of hosts whose home is in the area, but who currently visiting another area is ……………..
(A) Home agent (B) Mobile agent
(C) Foreign agent (D) User agent
Answer: A
35. In ………………. to send a multicast message a host sends it to the core, which then does the multicast along the spanning tree.
(A) Core based Trees (B) AVL trees
(C) Binary trees (D) Sparse trees
Answer: A
36. Sending a packet to all destinations simultaneously is called ……………….
(A) Multicasting (B) Unicasting
(C) Telecasting (D) Broadcasting
Answer: D
37. A normal Flooding technique is an example of ………………
(A) Multicasting (B) Unicasting
(C) Telecasting (D) Broadcasting
Answer: D
38. In Broadcast routing, if the router does not know anything all about spanning tree, ………………. method is preferred.
(A) Reverse Path forwarding (B) Multidestination
(C) Flooding (D) spanning tree
Answer: A
39. The method of Broadcast routing in which each packet contains either a list of destinations or a bit map indicating the desired destinations is ……………….
(A) Reverse Path forwarding (B) Spanning tree
(C) Multidestination (D) Flooding
Answer: C
40. Sending a message to a well defined group that are numerically large in size but small compared to the network as a whole is called ……………….
(A) Unicasting (B) Multicasting
(C) Broadcasting (D) None of these
Answer: B
COMPUTER NETWORKS Objective Questions with Answers :-
41. In link state routing, after the construction of link state packets new routes are computed using …………………
(A) Bellman Ford algorithm (B) DES algorithm
(C) Dijkstra’s algorithm (D) Leaky bucket algorithm
Answer: C
42. Count-to-Infinity problem occurs in …………………
(A) distance vector routing (B) short path first
(C) link state routing (D) hierarchical routing
Answer: A
43. In distance vector routing algorithm, each router maintains a separate routing table with the following entries.
(A) preferred input line , estimated time
(B) preferred input line, estimated distance
(C) preferred output line, estimated time
(D) preferred output line, router
Answer: C
44. Link state packets are built in ………………..
(A) short path first (B) distance vector routing
(C) link state routing (D) hierarchical routing
Answer: B
45. In which routing method do all the routers have a common database?
(A) Distance Vector (B) Link Vector
(C) Shortest path (D) Link State
Answer: D
46. In distance vector routing algorithm, the routing tables are updated …………………
(A) by exchanging information with the neighbours
(B) automatically
(C) using the backup database
(D) by the server
Answer: A
47. Distance vector routing algorithm is implemented in Internet as ……………………
(A) OSPF (B) RIP
(C) ARP (D) APR
Answer: B
48. Which of the following routing algorithm takes into account the current network load.
(A) broadcast (B) shortest path
(C) flooding (D) distance vector routing
Answer: D
49. In distance vector routing the delay metric is ……………….
(A) number of hops (B) geographical distance
(C) number of neighbours (D) queue length
Answer: D
50. In AODV routing algorithm for MANETs, the route is discovered at time
(A) only when the network is established
(B) in middle of the transmission
(C) when there is a need for route by the host
(D) when there is no need for route by the host
Answer: C
51. Military vehicles on a battlefield with no existing infrastructure will deploy …………… network.
(A) MANET (B) Cell Network
(C) LAN (D) Wi-Fi
Answer: A
52. The network in which all the nodes are symmetric and there is no central control or hierarchy is ……………..
(A) MANET (B) Client -Server Technology
(C) Peer-to-Peer (D) None of these
Answer: C
53. What is the type of network in which the topology change from time to time?
(A) Wi-Fi (B) Cell Network
(C) LAN (D) MANET
Answer: D
54. The processes that keep track of all mobile hosts visiting the area is ……………..
(A) Home agent (B) Mobile agent
(C) Foreign agent (D) User agent
Answer: C
55. The hosts which are basically stationary hosts who move from one fixed site to another from time to time but use the network only when they are physically connected to it are called …………….
(A) Migratory hosts (B) Stationary hosts
(C) Mobile hosts (D) Random hosts
Answer: A
56. The hosts who compute on the run and want to maintain their connections as they move around ……………
(A) Migratory hosts (B) Stationary hosts
(C) Mobile hosts (D) Random hosts
Answer: C
57. What is the type of network in which the routers themselves are mobile?
(A) Wide Area Network (B) Mobile Ad hoc Network
(C) Mobile Network (D) Local Area Network
Answer: B
58. What is the routing algorithm used in MANETs?
(A) Shortest Path First
(B) Routing Information Protocol
(C) Distance Vector Protocol
(D) Ad hoc On -demand Distance Vector Protocol
Answer: D
59. Why probe packets are transmitted in the network?
(A) to know about the capacity of the channel
(B) to count the number of host in the network
(C) to know about efficiency of the routing algorithm
(D) to know about the congestion
Answer: D
60. If the source deduces the existence of congestion by making local observations, such as the time needed for acknowledgements to come back is called as ……………..
(A) Explicit feedback algorithm (B) Implicit feedback algorithm
(C) Explicit forward algorithm (D) Implicit forward algorithm
Answer: B
61. Packet discard policy is implemented in ……………..
(A) Physical layer (B) Data link layer
(C) MAC layer (D) Network layer
Answer: D
62. The solution to decrease the load on the network when congestion occurs is ……………..
(A) splitting the traffic over multiple routes
(B) increasing the transmission power
(C) usage of spare routers
(D) denying service to the users
Answer: D
63. While booting the system the IP address is …………….
(A) 1.1.1.1 (B) 1.1.0.0
(C) 0.0.1.1 (D) 0.0.0.0
Answer: D
64. In open loop congestion control techniques, the decisions are based on the ……………
(A) without regard to the current state of the network
(B) with regard to the current state of the network
(C) with regard to the choice of the host
(D) without regard to the choice of the host
Answer: A
65. In closed loop congestion control techniques, the decisions are based on the ……………..
(A) concept of a feedback loop
(B) concept of a forward loop
(C) concept of current state of network
(D) None of these
Answer: A
66. ..………..is used to validate the identity of the message sender to the recipient
(A) Encryption (B) Decryption
(C) Digital certificate (D) None of these
Answer: C
67. When too many packets are present in the subnet, and performance degrades then it leads to ………………..
(A) Ingestion (B) Congestion
(C) Digestion (D) Diffusion
Answer: B
68. What is it goal of congestion control?
(A) making sure that subnet is not able to carry the offered traffic
(B) making sure that subnet will allow more than the offered packets
(C) making sure that subnet is able to carry the offered traffic
(D) making sure that subnet will not allow any traffic
Answer: C
69. The service of open loop congestion control technique is …………………..
(A) monitor the system to detect when and where congestion occurs
(B) when to accept new traffic
(C) pass the information to places where action can be taken
(D) adjusting the system to correct the problem
Answer: B
70. In …………… case higher bandwidth can be achieved.
(A) connectionless networks (B) connection oriented networks
(C) virtual circuit networks (D) optical networks
Answer: A
71. Time out determination policy is used in ………………….
(A) network layer (B) data link layer
(C) transport layer (D) application layer
Answer: C
72. In transport layer, End to End delivery is the movement of data from ……………….
(A) one station to the next station
(B) one network to the other network
(C) source to destination
(D) one router to another router
Answer: C
73. The service of closed loop congestion control technique is ………………
(A) when to accept new traffic
(B) when to discard the packets
(C) monitor the system to detect when and where congestion occurs
(D) which packets to discard
Answer: C
74. The solution to increase the capacity when congestion occurs is …………………
(A) denying service to the users
(B) degrading the service to the users
(C) splitting traffic over multiple routes
(D) rescheduled the demands of the users
Answer: C
75. When routers are being inundated by packets that they cannot handle, they just throw them away is known as ……………….
(A) Jitter control (B) Random early detection
(C) Choke packets (D) Load shedding
Answer: D
76. Upon receipt of a bad segment, UDP …………..
(A) It does flow control (B) It does error control
(C) Retransmission (D) It does not do flow and error control
Answer: D
77. When the source host receives the choke packet, then the source ………………
(A) reduces the capacity of the line
(B) reduces the line utilization factor
(C) reduces the traffic generation
(D) rate reduces the threshold value
Answer: C
78. If the buffer fills and a packet segment is dropped, then dropping all the rest of the segments from that packet, since they will be useless anyway is called ………………..
(A) Priority dropping (B) Tail dropping
(C) Age based dropping (D) None of these
Answer: B
79. Flow control policy is implemented in ………………….
(A) network layer (B) transport layer
(C) application layer (D) physical layer
Answer: B
80. For applications such as audio and video streaming, the variation in the packet arrival times is called ……………..
(A) Random early detection (B) Jitter
(C) Delay difference (D) Load shedding
Answer: B
81. Which of the following is required to communicate between two computers?
(A) communications software
(B) protocol
(C) communication hardware
(D) all of above including access to transmission medium
Answer: D
82. Terminals are required for ……………..
(A) real-time, batch processing & time-sharing
(B) real time, time-sharing & distributed message processing
(C) real time, distributed processing & manager inquiry
(D) real-time, time sharing & message switching
Answer: D
83. The first collision free protocol is ……………….
(A) Binary countdown (B) Basic bitmap
(C) Reservation protocol (D) SAP
Answer: B
84. Sending of a IP packet from host 1 to host 2 where both are of same LAN but the packet is transferred through different intermediate LANs is called ………………
(A) Tunnelling (B) Routing
(C) Diverting (D) Forwarding
Answer: A
85. LANs can be connected by a device called ……………..
(A) Routers (B) Modems
(C) Ethernet card (D) Bridges
Answer: D
86. In ……………….. all frames are given to the computer, not to those addressed.
(A) Promiscuous mode (B) Miscues mode
(C) Normal mode (D) Special Mode
Answer: A
87. ……………… Algorithm is used in transparent bridges.
(A) Forward Learning (B) Backward Learning
(C) Reverse Backward Learning (D) Reverse Forward Learning
Answer: B
88. In ………………… each packet of a message need not follow the same path From sender to receiver.
(A) Circuit switching
(B) message switching
(C) a virtual approach to packet switching
(D) The datagram approach to packet switching
Answer: D
89. FDDI is an acronym for ……………
(A) Fast data delivery interface (B) Fiber distributed data interface
(C) Fiber distributed digital interface (D) fast distributed data interface
Answer: B
90. ……………….. bridge operates in promiscuous mode.
(A) Transparent bridge (B) Selective flooding
(C) Source Routing (D) Remote Bridges
Answer: A
91. The address field of a frame in HDLC protocol contains the address of the ……………… station.
(A) primary (B) secondary
(C) tertiary (D) a station
Answer: B
92. In ………………. transmission, the channel capacity is shared by both communicating devices at all times.
(A) Simplex (B) half-duplex
(C) full-duplex (D) automatic
Answer: C
93. The DNS name space is divided into non overlapping ………………….
(A) regions (B) blocks
(C) divisions (D) zones
Answer: D
94. Source routing bridges in the same LANs must have …………… bridge Number.
(A) Same (B) Different
(C) Source (D) Destination
Answer: B
95. Repeater function in the …………………. layer.
(A) Physical (B) Data link
(C) Network (D) None of these
Answer: A
96. A repeater takes a weakened or corrupted signal and …………… it.
(A) Amplifies (B) Regenerates
(C) Resample (D) Reroute
Answer: B
97. The PSTN is an example of …………….. network.
(A) packet-switched (B) circuit-switched
(C) message-switched (D) TSI
Answer: B
98. In a time division switch, a ……………… governs the destination of a packet stored in RAM.
(A) TDM bus (B) cross bar
(C) cross point (D) control unit
Answer: D
99. How many cross points are needed in a single stage switch with 40 inputs and 50 outputs.
(A) 40 (B) 50
(C) 90 (D) 2000
Answer: D
100. The …………….. of A TSI controls the order of delivering of slot values that are stored in RAM.
(A) cross bar (B) cross point
(C) control unit (D) transceiver
Answer: D