Computer Network MCQ

1. Which transmission media has the highest transmission speed in a network?

a) coaxial cable
b) twisted pair cable
c) optical fiber
d) electrical cable

Answer: Optical fiber

2. What is the max data capacity of STP?

a) 10 mbps
b) 100 mbps
c) 1000 mbps
d) 10000 mbps

Answer: b) 100 mbps

3. In which topology there is a central controller or hub?

a) Star
b) Mesh
c) Ring
d) Bus

Answer: Star

4. 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: digital modulation

 5. A single channel is shared by multiple signals by

a) analog modulation In communication and computer networks, the main goal

b) digital modulation is to share a scarce resource. This is done by multiplexing,
c) multiplexing where multiple analog or digital signals are combined
d) none of the mentioned into one signal over a shared medium.

Answer: multiplexing

6. How long is an IPv6 address?

a) 32 bits
b) 128 bytes
c) 64 bits
d) 128 bits

Answer: 128 Bits

7. Communication between a computer and a keyboard involves ______________ transmission

a) Automatic
b) Half-duplex
c) Full-duplex
d) Simplex

Answer: simplex

8. MAC address is of

a) 24 bits
b) 36 bits
c) 42 bits
d) 48 bits

e) Answer: 48 bits
 9. Ethernet frame consists of

a) MAC address
b) IP address
c) both MAC address and IP address
d) none of the mentioned

Answer: a) MAC address

10. ICMP is primarily used for

a) error and diagnostic functions

b) addressing
c) forwarding
d) none of the mentioned

Answer: a) error and diagnostic functions (Internet Control Message Protocol)

11. What flavor of Network Address Translation can be used to have one IP address allow many
users to connect to the global Internet?

a) NAT
b) Static
c) Dynamic
d) PAT

Answer: PAT

12. 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) all of the mentioned

Answer: Router
 13. Which multiple access technique is used by IEEE 802.11 standard for wireless LAN?

a) CDMA
b) CSMA/CA
c) ALOHA
d) None of the mentioned

Answer: b) CSMA/CA

14. Multiplexing is used in _______

a) Packet switching
b) Circuit switching
c) Data switching
d) Packet & Circuit switching

Answer: b) Circuit switching

15. Which multiplexing technique transmits digital signals?

a) FDM
b) TDM
c) WDM
d) FDM & WDM

Answer: TDM (Time Division Multiplexing)

16. The state when dedicated signals are idle are called __________

a) Death period
b) Poison period
c) Silent period
d) None of the mentioned

Answer: c) Silent period

 17. Propagation delay depends on

a) Packet length
b) Transmission rate
c) Distance between the routers
d) None of the mentioned

Answer: c) Distance between the routers

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) none of the mentioned

Answer: protocol stack

19. A local telephone network is an example of a _______ network.

a) Packet switched
b) Circuit switched
c) Both Packet switched and Circuit switched
d) Line switched

Answer: b) Circuit switched

20. Most packet switches use this principle ____________

a) Stop and wait

b) Store and forward
c) Both Stop and wait and Store and forward
d) Stop and forward

Answer: b) Store and forward

 21. Bluetooth uses

a) frequency hoping spread spectrum

b) orthogonal frequency division multiplexing
c) time division multiplexing
d) none of the mentioned

Answer: a) frequency hoping spread spectrum

22. The default connection type used by HTTP is _________

a) Persistent
b) Non-persistent
c) Can be either persistent or non-persistent depending on connection request
d) None of the mentioned

Answer: a) Persistent

23. FTP is built on _____ architecture

a) Client-server
b) P2P
c) Both of the mentioned
d) None of the mentioned

Answer: a) Client-server

24. FTP uses _________ parallel TCP connections to transfer a file

a) 1
b) 2
c) 3
d) 4

Answer: 2
 25. If you have to send multimedia data over SMTP it has to be encoded into

a) Binary
b) Signal
c) ASCII
d) None of the mentioned

Answer: c) ASCII

26. Secure shell (SSH) network protocol is used for __________

a) secure data communication

b) remote command-line login
c) remote command execution
d) all of the mentioned

Answer: d) all of the mentioned

27. SSH uses ___________ to authenticate the remote computer.

a) public-key cryptography
b) private-key cryptography
c) any of public-key or private-key
d) both public-key & private-key

Answer: a) public-key cryptography

28. The number of layers in Internet protocol stack is_________

a) 5
b) 7
c) 6
d) None of the mentioned

Answer: 5 (Application, Transport, Network, Data link and Physical layer)

 29. Delimiting and synchronization of data exchange is provided by

a) Application layer
b) Session layer
c) Transport layer
d) Link layer

Answer: Session layer

30. What command is used to create a backup configuration?

a) copy running backup

b) copy running-config startup-config
c) config mem
d) wr mem

Answer: copy running-config startup-config

31. You have 10 users plugged into a hub running 10Mbps half-duplex. There is a server
connected to the switch running 10Mbps half-duplex as well. How much bandwidth does each
host have to the server?

a) 100 kbps
b) 1 Mbps
c) 2 Mbps
d) 10 Mbps

Answer: 10 Mbps

32. Which of the following is the valid host range for the subnet on which the IP address
192.168.168.188 255.255.255.192
resides? 256 - 192 = 64
64 + 64 = 128
a) 192.168.168.129-190 128 + 64 = 192
b) 192.168.168.129-191 The subnet is 128, the broadcast address is
c) 192.168.168.128-190 191, and the valid host range is the numbers
d) 192.168.168.128-192 in between, or 129-190.

Answer: 192.168.168.129-190
 33. To back up an IOS, what command will you use?

a) backup IOS disk

b) copy ios tftp
c) copy tftp flash
d) copy flash tftp

Answer: copy flash tftp

34. What protocol does PPP use to identify the Network layer protocol?

a) NCP Network Control Protocol is used to help

b) ISDN identify the Network layer protocol used
c) HDLC
in the packet.
d) LCP

Answer: NCP

35. Which of the following commands will allow you to set your Telnet password on a Cisco
router?

a) line telnet 0 4
b) line aux 0 4
c) line vty 0 4
d) line con 0

Answer: line vty 0 4

36. DHCP (dynamic host configuration protocol) provides __________ to the client.
a) IP address
b) MAC address
c) Url
d) None of the mentioned

Answer: a) IP address

37. 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) all of the mentioned

 38. 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) techniques applied to ensure the security of an existing DHCP infrastructure

39. Which protocol does DHCP use at the Transport layer?

a) IP
b) TCP
c) UDP
d) ARP
Answer: UDP

40. Which command is used to determine if an IP access list is enabled on a particular interface?

A. show access-lists
B. show interface
C. show ip interface
D. show interface access-lists

Answer: show ip interface

41. Where is a hub specified in the OSI model?

A. Session layer
B. Physical layer
C. Data Link layer
D. Application layer

Answer: Physical layer

42. IPsec is designed to provide the security at the

a) Transport layer
b) Network layer
c) Application layer
d) Session layer

Answer: b) Network layer

 43. Pretty good privacy (PGP) is used in

a) Browser security
b) Email security
c) FTP security
d) None of the mentioned

Answer: b) Email security

44. What does the passive command provide to dynamic routing protocols?

A. Stops an interface from sending or receiving periodic dynamic updates.

B. Stops an interface from sending periodic dynamic updates but not from receiving updates.
C. Stops the router from receiving any dynamic updates.
D. Stops the router from sending any dynamic updates.

Answer: B. Stops an interface from sending periodic dynamic updates but not from receiving
updates.

45. Which protocol is used to send a destination network unknown message back to originating
hosts?

A. TCP
B. ARP
C. ICMP ICMP is the protocol at the Network layer
D. BootP that is used to send messages back to an
originating router.

Answer: ICMP

46. ATM and frame relay are

a) virtual circuit networks

b) datagram networks
c) virtual private networks
d) none of the mentioned

Answer: a) virtual circuit networks

 47. ATM uses the

a) asynchronous frequency division multiplexing

b) asynchronous time division multiplexing
c) asynchronous space division multiplexing
d) none of the mentioned

Answer: a) asynchronous frequency division multiplexing

48. An ATM cell has the payload field of

a) 32 bytes
b) 48 bytes
c) 64 bytes
d) 128 bytes

Answer: a) 48 bytes

49. Frame relay has error detection at the

a) physical layer
b) data link layer
c) network layer
d) transport layer

Answer: b) data link layer

50. In classless addressing, there are no classes but addresses are still granted in

a) IPs
b) Blocks
c) Codes
d) Sizes

Answer: b) Blocks
 51. The header length of an IPv6 datagram is ___________

a) 10bytes
b) 25bytes
c) 30bytes
d) 40bytes

Answer: d) 40bytes

52. The main reason for transition from IPv4 to IPv6 is

a) Huge number of systems on the internet

b) Very low number of system on the internet
c) Providing standard address
d) None of the mentioned

Answer: a) Huge number of systems on the internet

53. Which of the following is the broadcast address for a Class B network ID using the default
subnetmask?

a) 172.16.10.255
b) 255.255.255.255
c) 172.16.255.255
d) 172.255.255.255

Answer: c) 172.16.255.255

54. You have an IP address of 172.16.13.5 with a 255.255.255.128 subnet mask. What is your class
of address, subnet address, and broadcast address?

a) Class A, Subnet 172.16.13.0, Broadcast address 172.16.13.127

b) Class B, Subnet 172.16.13.0, Broadcast address 172.16.13.127
c) Class B, Subnet 172.16.13.0, Broadcast address 172.16.13.255
d) Class B, Subnet 172.16.0.0, Broadcast address 172.16.255.255

Answer: b) Class B, Subnet 172.16.13.0, Broadcast address 172.16.13.127

 55. If you wanted to have 12 subnets with a Class C network ID, which subnet mask would you
use?

a) 255.255.255.252
b) 255.255.255.255
c) 255.255.255.240
d) 255.255.255.248

Answer: c) 255.255.255.240

56. Which router command allows you to view the entire contents of all access lists?

A. show all access-lists

B. show access-lists
C. show ip interface
D. show interface

Answer: show access-lists

57. Which class of IP address has the most host addresses available by default?

A. A
B. B
C. C
D. A and B

Answer: Class A (Class A addressing provides 24 bits for host addressing)

58. Which protocols are used for Storage management?

a) SNMP
b) LDAP
c) POP3
d) MIB

Answer: a) SNMP
 59. _______ allows you to connect and login to a remote computer

a) Telnet
b) FTP
c) HTTP
d) None of the mentioned

Answer: a) Telnet

60. What PPP protocol provides dynamic addressing, authentication, and multilink?

A. NCP
B. HDLC
C. LCP
D. X.25

Answer: LCP (Link Control Protocol)

61. What is a stub network?

A. A network with more than one exit point.

B. A network with more than one exit and entry point.
C. A network with only one entry and no exit point.
D. A network that has only one entry and exit point.

Answer: D. A network that has only one entry and exit point.

62. In TCP, sending and receiving data is done as

a) Stream of bytes
b) Sequence of characters
c) Lines of data
d) Packets

Answer: a) Stream of bytes

 63. TCP groups a number of bytes together into a packet called

a) Packet
b) Buffer
c) Segment
d) Stack

Answer: c) Segment

64. Which of the following is false with respect to UDP

a) Connection-oriented
b) Unreliable
c) Transport layer protocol
d) All of the mentioned

Answer: a) Connection-oriented

65. what is the header size of UDP packet?

a) 8 bytes
b) 8 bits
c) 16 bytes
d) 124 bytes

Answer: a) 8 bytes

66. The technique in which a congested node stops receiving data from the immediate upstream
node or nodes is called as

a) Admission policy
b) Backpressure
c) Forward signalling
d) Backward signalling

Answer: b) Backpressure
 67. Which one of the following is true regarding VLANs?

A. Two VLANs are configured by default on all Cisco switches.

B. VLANs only work if you have a complete Cisco switched internetwork. No off-brand switches are
allowed.
C. You should not have more than 10 switches in the same VTP domain.
D. VTP is used to send VLAN information to switches in a configured VTP domain.

Answer: D. VTP is used to send VLAN information to switches in a configured VTP domain.

68. What does a VLAN do?

A. Acts as the fastest port to all servers.

B. Provides multiple collision domains on one switch port.
C. Breaks up broadcast domains in a layer 2 switch internetwork.
D. Provides multiple broadcast domains within a single collision domain.

Answer: C. Breaks up broadcast domains in a layer 2 switch internetwork.

69. What is the main reason the OSI model was created?

A. To create a layered model larger than the DoD model.

B. So application developers can change only one layer's protocols at a time.
C. So different networks could communicate.
D. So Cisco could use the model.

Answer: C. So different networks could communicate.

70. Which protocol does Ping use?

A. TCP
B. ARP
C. ICMP
D. BootP

Answer: ICMP

(ICMP is the protocol at the Network layer that is used to send echo requests and replies.)
71. In the transfer of file between server and client, if the transmission rates along the path is
10Mbps, 20Mbps, 30Mbps, 40Mbps. The throughput is usually

a) 20Mbps
b) 10Mbps
c) 40Mbps
d) 50Mbps

Answer: 10 Mbps [The throughput is generally the transmission rate of bottleneck link.]

72. In a network with dozens of switches, how many root bridges would you have?

A. 1
B. 2
C. 5
D. 12

Answer: 1 (You should have only one root bridge per network)

73. Application Layer protocols are HTTP, FTP, SSH, DNS etc.

74. Presentation Layer protocols are SSL, MPEG, JPEG etc.

75. Session Layer protocols are API’s , Sockets etc.

76. Transport Layer protocols are TCP, UDP

77. Network Layer protocols are routing, IP, IPsec, ICMP, Packets etc.

78. Datalink Layer Protocols are Frame, PPP, Switch, Bridge etc.

79. Physical Layer Protocols are Coax, Fiber, Hubs, repeaters etc.

80. Address Resolution Protocol ( ARP ) is used to find the hardware address of a local device.

81. BUS, Ring and Star Topologies are mostly used in LAN

82. Connection of telephone regional office is a practical example of MESH topology.

83. Cable TV and DSL are example of MAN.

84. Repeaters are used in Ring topology.

85. Modulator and Demodulator combinely known as Modem.

86. BUS backbone uses LAN and Bridges.

87. Star backbone uses Switch.

88. IEEE 802.3 is ETHERNET

89. Repeater works with volts or signals.

90. Getway connects different networks.

91. Class C starts with 110 (binary) or 192 (dotted decimal)

92. Session, Presentation and Application layers are user supported.

93. Kerbaros is an authentication service for passwords.

94. TCP is connection Oriented.

95. IEEE 802.11 is a slang name for Wi-Fi

96. In class A the range is 1-126 and there are 16M host.

97. In class B the range is 128-191 and there are 64k host.

98. In class C the range is 192-223 and there are 254 host

99. Class D is used for Brodcasting

100. Class E used for future use.