Question 1

When the Protocol field of an IP header contains the value 17 (0x11), the UDP header follows the IP header.
Indicate the answer choice that best completes the statement or answers the question.

Accepted Answer

The Protocol field in the IP header specifies the next level protocol used in the data portion of the IP datagram. A value of 17 (0x11 in hexadecimal) indicates that the User Datagram Protocol (UDP) header follows the IP header.

Question 2

The initial sequence number used in a TCP connection is defined by the which of the following and, for security purposes, should be randomly assigned?
A)host
B)packet
C)port
D)segment

Accepted Answer

The initial sequence number in a TCP connection is defined by the host and, for security purposes, should be randomly assigned to make it more difficult for attackers to predict the sequence of packets, thereby enhancing the security of the connection.

Question 3

TCP keep-alives are enabled by default on Windows XP, Windows Vista, Windows 7, Windows Server 2003, and Windows Server 2008, although any application may disable TCP keep-alives, if desired by its programmer.

Accepted Answer

False

Question 4

Which of the following defines the length of the packet from the UDP header to the end of valid data (not including any data link padding, if padding is required)?
A)Checksum field
B)Dynamic Port Number field
C)Length field
D)Destination Port Number field

Accepted Answer

The Length field in the UDP header specifies the length of the UDP header plus the UDP data. This means it defines the length of the packet from the start of the UDP header to the end of the valid data, not including any padding that might be added at the data link layer for alignment purposes.

Question 5

Which of the following is detected whenever three or more duplicate ACK packets (known as a triple-ACK) or timeout events occur, and timeout events are considered more serious than duplicate acknowledgments?
A)Logical connection
B)Congestion
C)Retransmission
D)Windowing

Accepted Answer

Congestion in a network is detected when three or more duplicate ACK packets (a triple-ACK) or timeout events occur. Timeout events are considered more serious indicators of congestion than duplicate acknowledgments because they suggest a more significant delay in packet delivery, often leading to the assumption that packets have been lost in the network due to congestion.

Question 6

UDP is the only connectionless TCP/IP protocol at the Transport layer.

Accepted Answer

UDP is a connectionless protocol, meaning that it does not establish a connection with the receiver before sending data. TCP, on the other hand, is a connection-oriented protocol, meaning that it establishes a connection with the receiver before sending data.

Question 7

What is used in order for TCP hosts to create a virtual connection with each other?
A)sliding window
B)handshake process
C)teardown sequence
D)retry mechanism

Accepted Answer

The handshake process is used by TCP hosts to establish a virtual connection with each other. This typically involves a three-way handshake process to synchronize and acknowledge the connection before data transmission begins.

Question 8

The TCP connection termination process requires how many packets?
A)one
B)two
C)three
D)four

Accepted Answer

The TCP connection termination process involves a four-step process known as a four-way handshake. This includes the FIN from the initiator, ACK from the receiver, FIN from the receiver, and finally, ACK from the initiator.

Question 9

Which of the following processes guarantees that packets are ordered properly and protects against missing segments?
A)watchdog
B)keep-alive
C)handshake
D)sequence and acknowledgment

Accepted Answer

Sequence and acknowledgment mechanisms in network protocols, such as TCP, ensure that packets are ordered correctly and protect against missing segments by requiring the receiver to acknowledge receipt of packets and allowing for retransmission of lost packets.

Question 10

Dynamic ports are used as which of the following for specific communications while they are underway?
A)temporary ports
B)core services
C)byte streams
D)lost segments

Accepted Answer

Dynamic ports are used as temporary ports for specific communications while they are underway, allowing for flexible and temporary communication sessions between devices.

Question 11

Which of the following does TCP support, which is defined as the process of sending numerous data packets in sequence without waiting for an intervening acknowledgment?
A)retries
B)sequence number tracking
C)windowing
D)error recovery

Accepted Answer

Windowing is a feature of TCP that allows for the sending of multiple packets before requiring an acknowledgment, thereby increasing the efficiency of data transmission.

Question 12

Once a TCP connection is established, which of the following can maintain the connection when there is no data sent across the wire?
A)watchdog process
B)core service
C)keep-alive process
D)handshake process

Accepted Answer

The keep-alive process is responsible for maintaining a TCP connection when there is no data being sent. It periodically sends keep-alive messages to ensure the connection remains open even in periods of inactivity.

Question 13

UDP offers connection-oriented services with sequencing, error recovery, and a sliding window mechanism.

Accepted Answer

UDP (User Datagram Protocol) is a connectionless protocol that does not offer sequencing, error recovery, or a sliding window mechanism; these features are characteristic of TCP (Transmission Control Protocol).

Question 14

TCP half-open connections occur when the handshake process does not end successfully with a final ACK.

Accepted Answer

TCP half-open connections happen when one side of the connection terminates or interrupts the connection before the three-way handshake is completed, which means the final acknowledgment (ACK) is not sent or received, leaving the connection in an incomplete state.

Question 15

Which of the following does TCP support, which is a management method for data transmission used to determine the amount of unacknowledged data that can go out on the wire from any sender?
A)congestion mechanism
B)retry mechanism
C)sliding window mechanism
D)watchdog mechanism

Accepted Answer

TCP supports the sliding window mechanism, which is used to manage the flow of packets between two computers or network devices. It allows the sender to send multiple packets before needing an acknowledgment from the receiver, effectively managing the amount of unacknowledged data that can be in transit. This mechanism helps in controlling the flow of data and ensures efficient use of network resources, preventing congestion and data loss.

Question 16

When an out-of-order data segment is received, the Fast Retransmit process requires the receiver to immediately send which of the following?
A)duplicate ACKs
B)core services
C)byte streams
D)lost segments

Accepted Answer

Fast Retransmit is triggered by the receiver sending duplicate acknowledgements (ACKs) when an out-of-order segment is received, indicating that a segment was lost or received out of order and suggesting the sender to retransmit the missing data without waiting for a timeout.

Question 17

Overloading a receiver occurs when the number of data bytes is greater than which of the following?
A)advertised window
B)bandwidth
C)sliding window
D)ephemeral port

Accepted Answer

Overloading a receiver occurs when the number of data bytes sent is greater than the advertised window, which is the buffer space available at the receiver for storing incoming data before it is processed.

Question 18

Which of the following is a simple protocol that is used by applications that contain their own connection-oriented timeout values and retry counters, similar to those provided by TCP?
A)UDP
B)DoS
C)RTO
D)MSS

Accepted Answer

UDP (User Datagram Protocol) is a simple protocol used by applications that manage their own connection-oriented features like timeout values and retry counters, which are similar to the functionalities provided by TCP (Transmission Control Protocol). Unlike TCP, UDP is connectionless and does not guarantee delivery, leaving it up to the application to handle these tasks if needed.

Question 19

Which of the following is caused when enough data is sent to a TCP host to fill its receiver buffer, thereby putting the receiver in a zero-window state.
A)DoS
B)Silly Window Syndrome
C)Time Wait delay
D)Retransmission timeout

Accepted Answer

Silly Window Syndrome occurs when the receiver's buffer is full, leading to inefficient use of network resources and causing the receiver to advertise a zero-window size, indicating it cannot accept more data until it processes some of the buffered data.

Question 20

The Fast Recovery process dictates that when a host receives three duplicate ACKs, it must immediately start retransmitting which of the following without waiting for the retransmission timer to expire.
A)duplicate ACKs
B)core services
C)byte streams
D)lost segments

Accepted Answer

The Fast Recovery process in TCP is designed to quickly recover from packet loss that is detected when three duplicate ACKs are received. It does this by retransmitting the lost segment(s) without waiting for the retransmission timer to expire, assuming that the receipt of duplicate ACKs is an indication of a single lost segment.

Quiz 9: Tcp/ip Transport Layer Protocols

When the Protocol field of an IP header contains the value 17 (0x11), the UDP header follows the IP header. Indicate the answer choice that best completes the statement or answers the question.

The initial sequence number used in a TCP connection is defined by the which of the following and, for security purposes, should be randomly assigned?

TCP keep-alives are enabled by default on Windows XP, Windows Vista, Windows 7, Windows Server 2003, and Windows Server 2008, although any application may disable TCP keep-alives, if desired by its programmer.

Which of the following defines the length of the packet from the UDP header to the end of valid data (not including any data link padding, if padding is required) ?

Which of the following is detected whenever three or more duplicate ACK packets (known as a triple-ACK) or timeout events occur, and timeout events are considered more serious than duplicate acknowledgments?

UDP is the only connectionless TCP/IP protocol at the Transport layer.

What is used in order for TCP hosts to create a virtual connection with each other?

The TCP connection termination process requires how many packets?

Which of the following processes guarantees that packets are ordered properly and protects against missing segments?

Dynamic ports are used as which of the following for specific communications while they are underway?

Which of the following does TCP support, which is defined as the process of sending numerous data packets in sequence without waiting for an intervening acknowledgment?

Once a TCP connection is established, which of the following can maintain the connection when there is no data sent across the wire?

UDP offers connection-oriented services with sequencing, error recovery, and a sliding window mechanism.

TCP half-open connections occur when the handshake process does not end successfully with a final ACK.

Which of the following does TCP support, which is a management method for data transmission used to determine the amount of unacknowledged data that can go out on the wire from any sender?

When an out-of-order data segment is received, the Fast Retransmit process requires the receiver to immediately send which of the following?

Overloading a receiver occurs when the number of data bytes is greater than which of the following?

Which of the following is a simple protocol that is used by applications that contain their own connection-oriented timeout values and retry counters, similar to those provided by TCP?

Which of the following is caused when enough data is sent to a TCP host to fill its receiver buffer, thereby putting the receiver in a zero-window state.

The Fast Recovery process dictates that when a host receives three duplicate ACKs, it must immediately start retransmitting which of the following without waiting for the retransmission timer to expire.