Transport and Application Layer | Quiz with Answers

1.  If a TCP socket is ready and listening for incoming connections, it's in the ______ state. 
  ESTABLISHED
  CLOSE_WAIT
  SYN_SENT
  LISTEN 

           Answer - LISTEN

Explanation - The LISTEN state means that a port is waiting for something to connect to it. 

  
2.  The most common example of a connection-oriented protocol is _____
  UDP
  TCP
  IP 

Answer - TCP

Explanation - Other examples of connection-oriented protocols exist, but TCP is, by far, the most common. 

3.  The sequence of SYN, SYN/ACK, and ACK packets is known as the _________.

three-way handshake 
four-way handshake
two-way handshake
high five  

Answer - three-way handshake

Explanation - That series of flags is used to establish every TCP connection.




4.  Ports that are generally used to establish outbound connections are known as ______ ports.
  system
  reserved
  ephemeral
  registered 

Answer - ephemeral

 Explanation - The exact ports used are different, depending on the operating system, but they're all known as ephemeral ports.

 5.  How many bits are used to direct traffic to specific services running on a networked computer?
  16
  32
  8
  12 

 Answer - 16

 Explanation - A port is a 16-bit number that's used to direct traffic to specific services running on a networked computer.


6.  A network has the ability to direct traffic toward all of the receiving services. What provides this ability in the transport layer?
  File Transfer
  Multiplexing
  Socket address
  Demultiplexing 

Answer -  Multiplexing

 Explanation - Multiplexing in the transport layer means that nodes on a network have the ability to direct traffic toward many different receiving services.


7.  A connection has been terminated and no communication is possible. What is the Transmission Control Protocol (TCP) socket state?
  FINISHED
  CLOSE_WAIT
  FIN_WAIT
  CLOSED 

 Answer - CLOSED

 Explanation - The TCP socket will be in the CLOSED state when the connection has been fully terminated and no further communication is possible.


8.  Which field in a Transmission Control Protocol (TCP) header is chosen from ephemeral ports?
  Sequence number
  Source port
  Destination port
  Acknowledgement number

Answer -  Source port

Explanation - A source port is a high-numbered port chosen from a special section of ports known as ephemeral ports.


9. How many bits are reserved for the Transmission Control Protocol (TCP) flags?
  10
  8
  6
  4 

Answer - 6

Explanation - 6 bits are reserved for the 6 TCP control flags.


10. A connection, at which layer, implies that every segment of data sent is acknowledged?
  Data link
  Network
  Transport
  Application 

Answer -  Transport

Explanation - A connection at the transport layer implies that every segment of data sent is acknowledged.

11. Connection-oriented protocols protect against dropped data by forming connections and using what type of constant stream?
  Acknowledgements
  Verifiers
  Approvals
  Checks  

 Answer - Acknowledgements

 Explanation - Connection-oriented protocols protect against dropped data with a constant stream of acknowledgements.

12. How many Transmission Control Protocol (TCP) control flags are there?
  6
  5
  7
  8

  Answer - 6

 Explanation - There are 6 TCP control flags. 

 13. One side in a Transmission Control Protocol (TCP) connection has not been able to properly recover from a series of malformed segments. Which Transmission Control Protocol (TCP) flag will be used?
  PSH
  FIN
  SYN
  RST 

 Answer - RST

 Explanation - The RST flag is short for reset. This flag will start the communication from scratch, if one side cannot recover from a series of missing or malformed segments.

14.Which Transmission Control Protocol (TCP) flag is used to make sure the receiving end knows how to examine the sequence number field?
  ACK
  SYN
  PSH
  URG

  Answer - SYN

  Explanation -Answer - The SYN flag is used to make sure the receiving end knows how to examine the sequence number field.