This set of Computer Networks Multiple Choice Questions & Answers (MCQs) focuses on
“Transport Layer”.
1. 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.
2. 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.
3. 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.
4. 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.
5. 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.
6. 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.
7. 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.
8. 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.
9. 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.
10. 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.
• Question 1
Which action is performed by a client when establishing communication with a server via
the use of UDP at the transport layer?
answer choices
The client randomly selects a source port number.
The client sends a synchronization segment to begin the session.
The client sets the window size for the session
The client sends an ISN to the server to start the 3-way handshake.
• Question 2
Which number or set of numbers represents a socket?
answer choices
10.1.1.15
01-23-45-67-89-AB
21
192.168.1.1:80
• Question 3
Which transport layer feature is used to guarantee session establishment?
answer choices
UDP ACK flag
TCP 3-way handshake
TCP port number
UDP sequence number
• Question 4
What OSI layer is responsible for establishing a temporary communication session between
two applications and ensuring that transmitted data can be reassembled in proper sequence?
answer choices
Session
Transport
Data link
network
• Question 5
What is an advantage of UDP over TCP?
answer choices
UDP communication is more reliable.
UDP communication requires less overhead.
UDP reorders segments that are received out of order.
UDP acknowledges received data.
• Question 6
T/F
Multiplexing divides the data into smaller segments and enables communications from many
different users to be interleaved
answer choices
True
False
• Question 7
T/F
The Transport layer is responsible for managing reliability requirements of a conversation
answer choices
False
True
• Question 8
T/F
UDP is also known as a best-effort delivery protocol
answer choices
True
False
• Question 9
T/F
UDP is a stateful protocol that keeps track of the state of the communication session
answer choices
False
True
• Question 10
POP3 port number is
answer choices
23
110
161
80
• Question 11
HTTP/HTTPS port number
answer choices
80 and 443
80 and 445
67 and 68
161 and 69
• Question 12
Which TCP header control bit is set on to terminate a TCP conversation
answer choices
UrG
ACK
PSH
FIN
• Question 13
What is assigned by the transport layer to identify an application or service
answer choices
Segment
Packet
Port
IP Address
• Question 14
Ephemeral Ports - also known as?
answer choices
Well-known
Registered
Dynamic or Private
• Question 15
Who assigns Registered Ports
answer choices
ICANN
IANA
RIPE
IETF
• Question 16
What is the purpose of using a source port number in a TCP communication?
answer choices
to notify the remote device that the conversation is over
to keep track of multiple conversations between devices
to assemble the segments that arrived out of order
to inquire for a non-received segment
• Question 17
T/F
Only one host needs to support SACK
answer choices
True
False
1. Explain the main idea of UDP?
The basic idea is for a source process to send a message to a port and for the
destination process to receive the message from a port.
2. What are the different fields in pseudo header?
·
Protocol number
·
Source IP address
·
Destination IP addresses.
3. Define TCP?
TCP guarantees the reliable, in order delivery of a stream of bytes. It is a fullduplex protocol, meaning that each TCP connection supports a pair of byte streams,
one flowing in each direction.
4. Define Congestion Control?
It involves preventing too much data from being injected into the network,
thereby causing switches or links to become overloaded. Thus flow control is an end
to an end issue, while congestion control is concerned with how hosts and networks
interact.
5. State the two kinds of events trigger a state transition?
·
A segment arrives from the peer.
·
The local application process invokes an operation on TCP.
6. What is meant by segment?
At the sending and receiving end of the transmission, TCP divides long
transmissions into smaller data units and packages each into a frame called a
segment.
7. What is meant by segmentation?
When the size of the data unit received from the upper layer is too long for
the network layer datagram or data link layer frame to handle, the transport protocol
divides it into smaller usable blocks. The dividing process is called segmentation.
8. What is meant by Concatenation?
The size of the data unit belonging to single sessions are so small that several can fit
together into a single datagram or frame, the transport protocol combines them into a
single data unit. The combining process is called concatenation.
9. What is rate based design?
Rate- based design, in which the receiver tells the sender the rate-expressed in either
bytes or packets per second – at which it is willing to accept incoming data.
10. Define Gateway.
A device used to connect two separate networks that use different communication
protocols.
11. What is meant by quality of service?
The quality of service defines a set of attributes related to the performance of the
connection. For each connection, the user can request a particular attribute each
service class is associated with a set of attributes.
12. What are the two categories of QoS attributes?
The two main categories are,
·
User Oriented
·
Network Oriented
13. List out the user related attributes?
User related attributes are SCR – Sustainable Cell Rate PCR – Peak Cell Rate MCRMinimum Cell Rate CVDT – Cell Variation Delay Tolerance.
14. What are the networks related attributes?
The network related attributes are, Cell loss ratio (CLR) Cell transfer delay (CTD)
Cell delay variation (CDV) Cell error ratio (CER).
15. What is RED?
Random Early Detection in each router is programmed to monitor its own queue
length and when it detects that congestion is imminent, to notify the source to adjust
its congestion window.
16. What are the three events involved in the connection?
For security, the transport layer may create a connection between the two end
ports. A connection is a single logical path between the source and destination that is
associated with all packets in a message. Creating a connection involves three steps:
·
Connection establishment
·
Data transfer
·
Connection release
17.What is Silly Window Syndrome?
If the sender or the receiver application program processes slowly and can send only
1 byte of data at a time, then the overhead is high.This is because to send one byte of
data, 20 bytes of TCP header and 20 bytes of IP header are sent. This is called as silly
window syndrome.
1. 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
2. Which one of the following is a transport layer protocol used in internet?
•
•
•
•
A. TCP
B. UDP
C. both (a) and (b)
D. none of the mentioned
3. 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. both (a) and (b)
D. none of the mentioned
4. Transmission control protocol is:
• A. connection oriented protocol
• B. uses a three way handshake to establish a connection
• C. recievs data from application as a single stream
• D. All of the mentioned
5. An endpoint of an inter-process communication flow across a computer network is
called:
•
•
•
•
A. socket
B. pipe
C. port
D. none of the mentioned
6. Socket-style API for windows is called:
•
•
•
•
A. wsock
B. winsock
C. wins
D. none of the mentioned
7. 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. none of the mentioned
8. A _____ is a TCP name for a transport service access point.
•
•
•
•
A. port
B. pipe
C. node
D. none of the mentioned
9. Transport layer protocols deals with:
•
•
•
•
A. application to application communication
B. process to process communication
C. node to node communication
D. none of the mentioned
10. Which one 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
1.
An endpoint of an inter-process communication flow across a computer network is called
A.) socket
B.) pipe
C.) port
D.) none of these
Answer: Option 'A'
socket
2.
Which one of the following is a transport layer protocol?
A.) stream control transmission protocol
B.) neighbor discovery protocol
C.) internet control message protocol
D.) dynamic host configuration protocol
Answer: Option 'A'
dynamic host configuration protocol
3.
Transmission control protocol is
A.) connection oriented protocol
B.) uses a three way handshake to establish a connection
C.) recievs data from application as a single stream
D.) all of these
Answer: Option 'D'
all of these
4.
Transport layer aggregates data from different applications into a single stream before passing it to
A.) application layer
B.) network layer
C.) data link layer
D.) physical layer
Answer: Option 'B'
network layer
5.
Which one of the following is a transport layer protocol used in internet?
A.) TCP
B.) UDP
C.) both (a) and (b)
D.) none of these
Answer: Option 'C'
both (a) and (b)
1.
Transport layer aggregates data from different applications into a single stream before passing it to
A.) application layer
B.) network layer
C.) data link layer
D.) physical layer
Answer: Option 'B'
network layer
2.
Transmission control protocol is
A.) connection oriented protocol
B.) uses a three way handshake to establish a connection
C.) recievs data from application as a single stream
D.) all of these
Answer: Option 'D'
all of these
3.
A _____ is a TCP name for a transport service access point.
A.) pipe
B.) port
C.) node
D.) none of these
Answer: Option 'B'
port
4.
Socket-style API for windows is called
A.) wsock
B.) winsock
C.) wins
D.) None of these
Answer: Option 'B'
winsock
5.
Which one of the following is a transport layer protocol used in internet?
A.) TCP
B.) UDP
C.) both (a) and (b)
D.) none of these
Answer: Option 'C'
both (a) and (b)
6.
Transport layer protocols deals with
A.) application to application communication
B.) process to process communication
C.) node to node communication
D.) none of these
Answer: Option 'B'
process to process communication
7.
Socket-style API for windows is called
A.) wsock
B.) winsock
C.) wins
D.) None of these
Answer: Option 'B'
winsock
8.
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.) both (a) and (b)
D.) None of these
Answer: Option 'C'
both (a) and (b)
9.
A _____ is a TCP name for a transport service access point.
A.) pipe
B.) port
C.) node
D.) none of these
Answer: Option 'B'
port
10.
Transport layer aggregates data from different applications into a single stream before passing it to
A.) application layer
B.) network layer
C.) data link layer
D.) physical layer
Answer: Option 'B'
network layer
11.
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.) both (a) and (b)
D.) None of these
Answer: Option 'C'
both (a) and (b)
1. Network congestion has resulted in the source learning of the loss of TCP
segments that were sent to the destination. What is one way that the TCP
protocol addresses this?
• The source decreases the amount of data that it transmits before it receives an
acknowledgement from the destination.
• The source decreases the window size to decrease the rate of transmission from the
destination.
• The destination decreases the window size.
• The destination sends fewer acknowledgement messages in order to conserve bandwidth.
Explanation: If the source determines that the TCP segments are either not being acknowledged or
are not acknowledged in a timely manner, then it can reduce the number of bytes it sends before
receiving an acknowledgment. This does not involve changing the window in the segment header.
The source does not decrease the window that is sent in the segment header. The window in the
segment header is adjusted by the destination host when it is receiving data faster than it can
process it, not when network congestion is encountered.
2. Which two operations are provided by TCP but not by UDP? (Choose two.)
•
•
•
•
•
identifying the applications
acknowledging received data
tracking individual conversations
retransmitting any unacknowledged data
reconstructing data in the order received
Explanation: Numbering and tracking data segments, acknowledging received data, and
retransmitting any unacknowledged data are reliability operations to ensure that all of the data
arrives at the destination. UDP does not provide reliability. Both TCP and UDP identify the
applications and track individual conversations. UDP does not number data segments and
reconstructs data in the order that it is received.
3. What is the TCP mechanism used in congestion avoidance?
•
•
•
•
three-way handshake
socket pair
two-way handshake
sliding window
Explanation: TCP uses windows to attempt to manage the rate of transmission to the maximum
flow that the network and destination device can support while minimizing loss and
retransmissions. When overwhelmed with data, the destination can send a request to reduce the of
the window. This congestion avoidance is called sliding windows.
4. What is a responsibility of transport layer protocols?
•
•
•
•
providing network access
tracking individual conversations
determining the best path to forward a packet
translating private IP addresses to public IP addresses
Explanation: There are three main responsibilities for transport layer protocols TCP and UDP:
• Tracking individual conversations
• Segmenting data and reassembling segments
• Identifying the applications
5. How does a networked server manage requests from multiple clients for different services?
•
•
•
•
The server sends all requests through a default gateway.
Each request is assigned source and destination port numbers.
The server uses IP addresses to identify different services.
Each request is tracked through the physical address of the client.
Explanation: Each service provided by a server, such as email or file transfers, uses a specific port
number. The source port number of a service request identifies the client that is requesting services.
The destination port number identifies the specific service. Servers do not use address information
to provide services. Routers and switches use addressing information to move traffic through the
network.
6. Which two services or protocols use the preferred UDP protocol for fast transmission and
low overhead? (Choose two)
•
•
•
•
•
FTP
DNS
HTTP
POP3
VoIP
Explanation: Both DNS and VoIP use UDP to provide low overhead services within a network
implementation.
7. What is the purpose of using a source port number in a TCP communication?
•
•
•
•
to notify the remote device that the conversation is over
to assemble the segments that arrived out of order
to keep track of multiple conversations between devices
to inquire for a nonreceived segment
Explanation: The source port number in a segment header is used to keep track of multiple
conversations between devices. It is also used to keep an open entry for the response from the
server. The incorrect options are more related to flow control and guaranteed delivery.
8. Which number or set of numbers represents a socket?
•
•
•
•
01-23-45-67-89-AB
21
192.168.1.1:80
10.1.1.15
Explanation: A socket is defined by the combination of an IP address and a port number, and
uniquely identifies a particular communication.
9. Which two flags in the TCP header are used in a TCP three-way handshake to establish
connectivity between two network devices? (Choose two.)
•
•
•
•
•
•
ACK
FIN
PSH
RST
SYN
URG
Explanation: TCP uses the SYN and ACK flags in order to establish connectivity between two
network devices.
10. What happens if part of an FTP message is not delivered to the destination?
• The message is lost because FTP does not use a reliable delivery method.
• The FTP source host sends a query to the destination host.
• The part of the FTP message that was lost is re-sent.
• The entire FTP message is re-sent.
Explanation: Because FTP uses TCP as its transport layer protocol, sequence and acknowledgment
numbers will identify the missing segments, which will be re-sent to complete the message.
11. What type of applications are best suited for using UDP?
•
•
•
•
applications that are sensitive to delay
applications that need reliable delivery
applications that require retransmission of lost segments
applications that are sensitive to packet loss
Explanation: UDP is not a connection-oriented protocol and does not provide retransmission,
sequencing, or flow control mechanisms. It provides basic transport layer functions with a much
lower overhead than TCP. Lower overhead makes UDP suitable for applications which are sensitive
to delay.
12. Which action is performed by a client when establishing communication with a server via
the use of UDP at the transport layer?
•
•
•
•
The client sets the window size for the session.
The client sends an ISN to the server to start the 3-way handshake.
The client randomly selects a source port number.
The client sends a synchronization segment to begin the session.
Explanation: Because a session does not have to be established for UDP, the client selects a
random source port to begin a connection. The random port number selected is inserted into the
source port field of the UDP header.
13. Which transport layer feature is used to guarantee session establishment?
•
•
•
•
UDP ACK flag
TCP 3-way handshake
UDP sequence number
TCP port number
Explanation: TCP uses the 3-way handshake. UDP does not use this feature. The 3-way handshake
ensures there is connectivity between the source and destination devices before transmission occurs.
14. What is the complete range of TCP and UDP well-known ports?
•
•
•
•
0 to 255
0 to 1023
256 – 1023
1024 – 49151
Explanation: There are three ranges of TCP and UDP ports. The well-know range of port numbers
is from 0 – 1023.
15. What is a socket?
• the combination of the source and destination IP address and source and destination Ethernet
address
• the combination of a source IP address and port number or a destination IP address
and port number
• the combination of the source and destination sequence and acknowledgment numbers
• the combination of the source and destination sequence numbers and port numbers
Explanation: A socket is a combination of the source IP address and source port or the destination
IP address and the destination port number.
Question 1
DHCP allows both manual and automatic assignment of IP addresses. True or False?
True
False
• Question 2
In version field of IPv4 header, when machine is using some other version of IPv4 then datagram is
Accepted
Discarded
Interpreted
Interpreted incorrectly
• Question 3
Network layer at source is responsible for creating a packet from data coming from another
__________.
Link
Node
Station
Protocol
• Question 4
Header of datagram in IPv4 has __________.
0 to 20 bytes
20 to 40 bytes
20 to 60 bytes
20 to 80 bytes
• Question 5
In IPv4, service type of service in header field, first 3 bits are called __________.
Type of service
Code bits
Sync bits
Precedence bits
• Question 6
In IPv4, only thing encapsulated in a frame is _____.
Unit
Datagram
Adresses
Data Frame
• Question 7
In Internetwork, network layer is responsible for _______.
Host to User Link
User to Host IP
Host to Host Delivery
Host to Server communication
• Question 8
In IPv4, fragmented datagram's fragment size should have first byte number divisible by
_________.
2
4
8
16
• Question 9
In IPv4 protocol, each datagram is handled ____________.
independently
dependently
priority basis
systematically
• Question 10
IPv6 is designed to allow extension of the ___________.
Protocol
Routes
DataSet
Headers
• Question 11
Dividing a network address into smaller networks can be called as ___________.
encapsulation
subnetting
decapsulation
fragmentation
• Question 13
IPv6 consists of _____ bits.
32
64
128
256
• Question 14
IPv4 consists of ______ bits.
8
16
32
64
• Question 15
ICANN: Internet Corporation for Assigned Names and Numbers task:
manages DNS
allocates addresses
both answer
1. The network layer concerns with:
•
•
•
•
A. bits
B. frames
C. packets
D. none of the mentioned
2. Which one of the following is not a function of network layer?
•
•
•
•
A. routing
B. inter-networking
C. congestion control
D. none of the mentioned
3. The 4 byte IP address consists of:
• A. network address
• B. host address
• C. both (a) and (b)
• D. none of the mentioned
4. In virtual circuit network each packet contains:
•
•
•
•
A. full source and destination address
B. a short VC number
C. both (a) and (b)
D. none of the mentioned
5. Which one of the following routing algorithm can be used for network layer
design?
•
•
•
•
A. shortest path algorithm
B. distance vector routing
C. link state routing
D. all of the mentioned
6. Multidestination routing:
•
•
•
•
A. is same as broadcast routing
B. contains the list of all destinations
C. data is not sent by packets
D. none of the mentioned
7. 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. none of the mentioned
8. Which one of the following algorithm is not used for congestion control?
•
•
•
•
A. traffic aware routing
B. admission control
C. load shedding
D. none of the mentioned
9. The network layer protocol of internet is:
•
•
•
•
A. ethernet
B. internet protocol
C. hypertext transfer protocol
D. none of the mentioned
10. ICMP is primarily used for:
•
•
•
•
A. error and diagnostic functions
B. addressing
C. forwarding
D. none of the mentioned
1. The network layer is concerned with __________ of data.
a) bits
b) frames
c) packets
d) bytes
View Answer
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.
2. Which one of the following is not a function of network layer?
a) routing
b) inter-networking
c) congestion control
d) error control
View Answer
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.
3. 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
View Answer
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.
4. 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
View Answer
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.
5. 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
View Answer
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.
6. 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
View Answer
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.
7. 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
View Answer
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.
8. 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
View Answer
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.
9. The network layer protocol for internet is __________
a) ethernet
b) internet protocol
c) hypertext transfer protocol
d) file transfer protocol
View Answer
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.
10. ICMP is primarily used for __________
a) error and diagnostic functions
b) addressing
c) forwarding
d) routing
View Answer
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.
1. Which level is the network layer in the OSI model?
a) Third level
b) Fourth level
c) Second level
d) Fifth layer
View Answer
Answer: a
Explanation: The network layer is the third level of the open system interconnection model and the
layer that provides data routing paths for network communication.
2. Data in network layer is transferred in the form of ____________
a) Layers
b) Packets
c) Bytes
d) Bits
View Answer
Answer: b
Explanation: Data is transferred in the form of packets via logical network paths in an ordered
format controlled by the network layer.
3. The network layer is considered as the _______ of the network layer.
a) backbone
b) packets
c) bytes
d) bits
View Answer
Answer: a
Explanation: The network layer is considered as the backbone of the network layer. It selects and
manages the best logical path for data transfer between nodes.
4. The network layer contains which hardware device?
a) Routers, Bridges
b) Bridges only
c) Bridges and switches
d) Routers, Bridges and Switches
View Answer
Answer: d
Explanation: This layer contains hardware devices such as routers, bridges, firewalls, and switches,
but it actually creates a logical image of the most efficient communication rout and implements it
with a physical medium.
5. Network layer protocol exits in _________
a) Host
b) Switches
c) Packets
d) Bridges
View Answer
Answer: a
Explanation: Network layer protocols exits in every host or router. The router examines the header
fields of all the IP packets that pass through it.
6. What are the common protocols associated with the network layer?
a) Address Resolution Protocol
b) Reverse Address Resolution Protocol
c) Internet protocol
d) Neighbour Discovery Protocol
View Answer
Answer: c
Explanation: Internet protocol and Netware IPX/SPX are the most common protocols associated
with the network layer.
7. The network layer responds to request from which layer?
a) Transport layer
b) Data layer
c) Application layer
d) Session layer
View Answer
Answer: a
Explanation: In OSI model, we are having 7 layers in which the network layer responds to request
from the layer above it called Transport Layer.
8. The network layer issues request to which layer?
a) Transport layer
b) Data layer
c) Application layer
d) Session layer
View Answer
Answer: b
Explanation: In OSI model, we are having 7 layers in which the network layer issues request to the
layer below it called Data Link Layer.
9. IP is connectionless.
a) True
b) False
View Answer
Answer: a
Explanation: IP is connectionless, is that a data packet can travel from a sender to a receiver without
the recipient having to send an acknowledgment connection-oriented protocols exits at other, higher
layers of the OSI model.
10. Does network layer in TCP/IP and OSI Model are same.
a) True
b) False
View Answer
Answer: b
Explanation: The TCP/IP Internet layer is in fact only a subset of functionality of the network layer.
It describes only one type of network architecture, the Internet.
11. What are called routers?
a) The devices that operates at session layer
b) The devices that operates at data layer
c) The devices that operates at application layer
d) The devices that operates at network
View Answer
Answer: d
Explanation: The network interconnection devices that operate at the network layer are usually
called routes, which at this point should hopefully come as no surprise to you.
12. ICMP stands for __________
a) Internet Coordinate Message Protocol
b) Internet Control Message Protocol
c) Interconnect Control Message Protocol
d) Interconnect Coordinate Message Protocol
View Answer
Answer: b
Explanation: The Internet Protocol is the key network layer protocol that implements the TCP/IP
Protocol suites. Since IP is the protocol that provides the mechanism for delivering datagrams,
between devices, it is designed to be relatively basic, and to function with few “bell and whistles”.
13. Packets will be transferred in how many types?
a) 5 types
b) 4 types
c) 2 types
d) 3 types
View Answer
Answer: d
Explanation: Routing deals with determining how packet will routed (transferred) from source to
destination. It can of three types : 1. Static
2. Dynamic
3. Semi Dynamic.
14. DDP stands for _________
a) Datagram Delivery Protocol
b) Device Delivery Protocol
c) Datagram Device Protocol
d) Device Datagram Protocol
View Answer
Answer: a
Explanation: Datagram Delivery Protocol is a member of the AppleTalk networking protocol suite.
Its main responsibility is for socket to socket delivery of datagram over an AppleTalk network.
15. RIP stands for ________
a) Reduced Information Protocol
b) Routing Internet Protocol
c) Routing Information Protocol
d) Reduced Internet Protocol
View Answer
Answer: c
Explanation: The Routing Information Protocol is one of the oldest distance vector routing
protocols which employ the hop count as a routing metric.
Question 1
Q. Which of the following are network layer protocols?
IPv6
TCP
UDP
HTTP
• Question 2
Q. Which of the following is a characteristics of IP?
Ensure reliable end to end data transmission
Collisions are avoided in different transmission media
Sender doesn’t know if the receiver is listening or the message arrived on time
It provides information on the amounts of memory installed, what IOS images was loaded during
boot and more
• Question 3
Q. Why is IPv6 preferred over IPv4?
Better performance in terms of subnetting
Increased address space
Support higher transmission speed
Suitable for both wired and wireless networks
• Question 4
Q. What is the purpose of default gateway?
Enable routers to send packets using the default routes
Default gateways are layer 2 switches which forward packets to routers
A list of gateways for linking wired to wireless networks
Hosts will use the default gateway when sending packets to remote networks.
• Question 5
Q. What is the command to display host routing tables?
show ip route
netstat -r
arp -a
show run
• Question 6
Q. What is the "C" routes in Cisco Routing table?
Information on: how the route was learned, its trustworthiness and rating
Identifies a directly-connected network, automatically created when an interface is configured
with an IP address and activated.
Identifies that this is a local interface. This is the IPv4 address of the interface on the router.
Indicated the routes which are configured by users.
• Question 7
Q. What is the boot up sequence of a router?
POST, Load IOS, Load Startup, Bootstrap Loader
POST, Bootstrap Loader, Load IOS, Load Startup
Bootstrap Loader, Load IOS, POST, Load Startup
Load IOS, Load Startup, POST, Bootstrap Loader
• Question 8
Q. What is the purpose of show ip route?
Displays statistics for all routes on the device
Displays the contents of the IPv4 routing table stored in RAM
Displays the IPv6 routes for all interfaces on a router
Show how the content of routes stored in NVRAM
• Question 9
Q. How do you configure the default gateway of a switch?
ip default gateway
ip route 0.0.0.0 0.0.0.0 <interface>
ip default-gateway
default ip-gateway
• Question 10
Q. What is Routing?
to take the large network and filter it, without changing the size of the network.
to check messages are sent to the right device.
the process of finding a path on which data can pass from source to destination
provide optional services to an application developer
1.
Which one of the following routing algorithm can be used for network layer design?
A.) shortest path algorithm
B.) distance vector routing
C.) link state routing
D.) all of these
Answer: Option 'D'
all of these
2.
Which one of the following is not a function of network layer?
A.) routing
B.) inter-networking
C.) congestion control
D.) none of these
Answer: Option 'D'
none of these
3.
The network layer protocol of internet is
A.) internet protocol
B.) ethernet
C.) hypertext transfer protocol
D.) none of these
Answer: Option 'A'
internet protocol
4.
In virtual circuit network each packet contains
A.) full source and destination address
B.) a short VC number
C.) both (a) and (b)
D.) None of these
Answer: Option 'B'
a short VC number
5.
Which one of the following algorithm is not used for congestion control?
A.) traffic aware routing
B.) admission control
C.) load shedding
D.) None of these
Answer: Option 'D'
None of these
6.
ICMP is primarily used for
A.) error and diagnostic functions
B.) addressing
C.) forwarding
D.) none of these
Answer: Option 'A'
error and diagnostic functions
7.
Which one of the following is not a function of network layer?
A.) routing
B.) inter-networking
C.) congestion control
D.) none of these
Answer: Option 'D'
none of these
8.
In virtual circuit network each packet contains
A.) full source and destination address
B.) a short VC number
C.) both (a) and (b)
D.) None of these
Answer: Option 'B'
a short VC number
9.
The 4 byte IP address consists of
A.) network address
B.) host address
C.) both (a) and (b)
D.) none of the mentioned
Answer: Option 'C'
both (a) and (b)
10.
The network layer concerns with
A.) frames
B.) bits
C.) packets
D.) none of these
Answer: Option 'C'
packets