Exam Prep Questions

Question 1	Which two protocols operate at the Transport layer of the TCP/IP model? Choose 2. A. ICMP B. TCP C. IP D. UDP E. HTTP
A1:	Answers B and D are correct because TCP and UDP are both protocols that operate at the Transport layer of the TCP/IP model. Answers A and C are incorrect because ICMP and IP are both protocols that operate at the Internet layer of the TCP/IP model. Answer E is incorrect because HTTP is a protocol that operates at the Application layer of the TCP/IP model.
Question 2	Which of the following are characteristics of UDP? Choose 2. A. UDP has a high overhead. B. UDP is designed for applications that require a reliable Transport Layer mechanism. C. UDP is designed for applications that run on reliable networks. D. UDP is a connectionless, stateless, and unreliable protocol.
A2:	Answers C and D are correct because UDP is designed for applications that run on reliable networks and it is a connectionless, stateless, and unreliable protocol. Answer A is incorrect because UDP has a low overhead. Answer B is incorrect because TCP, not UDP, is designed for applications that require a reliable Transport layer mechanism.
Question 3	In a TCP segment header, what function does the window field carry out? A. It is reserved and is not used. B. It informs the sending system how many bytes can be sent. C. It informs the receiving system how many bytes can be sent. D. It defines the starting point of the data portion.
A3:	Answer B is correct because the window field contains the number of bytes that the sending system can send. Answer A is incorrect because the reserved field is not used. Answer C is incorrect because there is no field that informs the receiving system how many bytes can be sent. Answer D is incorrect because it is the offset field that denotes the starting point of the data portion of a TCP segment.
Question 4	This protocol is used at the Transport layer of the TCP/IP model and guarantees delivery of messages by using a virtual connection and an acknowledgement mechanism. Which protocol is being described? A. UDP B. ICMP C. TCP D. IP
A4:	Answer C is correct because TCP is a Transport layer protocol that guarantees delivery of messages by using a virtual connection and an acknowledgement mechanism. Answer A is incorrect because UDP, although it is a Transport layer protocol, is connectionless and unreliable ”that is, it does not implement any acknowledgement mechanism. Answers B and D are incorrect because ICMP and IP are Internet layer protocols.
Question 5	Which file contains the well known ports and the applications associated with them? A. /etc/inet/networks B. /etc/inet/services C. /etc/inet/ hosts D. /etc/nodename
A5:	Answer B is correct because the file /etc/inet/services contains the well known ports and the applications associated with them. Answer A is incorrect because the file /etc/inet/networks is used for mapping network numbers to network names . Answer C is incorrect because /etc/inet/hosts is used to provide IPv4 address to hostname mapping. Answer D is incorrect because /etc/nodename contains the canonical hostname for the system.
Question 6	When TCP initiates a connection, a number of messages and acknowledgements are sent and received to establish a viable link. What is this procedure called? A. A one-way handshake B. A two-way handshake C. A three-way handshake D. A four-way handshake
A6:	Answer C is correct because the procedure to establish a TCP connection is known as a three-way handshake, making answers A, B, and D obviously incorrect.
Question 7	In a UDP datagram header, what does the length field denote? A. The length of the datagram header, not including the data B. The length of the datagram, including the header and the data C. The length of the data portion of the datagram D. The length of the checksum field
A7:	Answer B is correct because the length field of a UDP datagram header denotes the length of the datagram, including the header and the data, making answers A, C, and D incorrect.
Question 8	Which of the following are valid fields in the TCP segment header? Choose 3. A. Source IP address B. Checksum C. Sequence number D. Acknowledgement number E. Maximum transfer unit F. Length
A8:	Answers B, C, and D are correct because checksum, sequence number, and acknowledgement number fields are all valid fields in a TCP segment header. Answer A is incorrect because the Source IP address field is present in an IP datagram header and not in a TCP segment header. Answer E is incorrect because the maximum transfer unit (MTU) is a valid field in an Ethernet frame and is not present in a TCP segment header. Answer F is incorrect because the length field is a valid field in a UDP datagram header.
Question 9	Which of the following are characteristics of TCP? Choose 2. A. TCP has a lower overhead than UDP. B. TCP is designed for applications that require a reliable Transport layer mechanism. C. TCP is designed for applications that run on reliable networks. D. TCP is a connection-oriented, stateful, and reliable protocol.
A9:	Answers B and D are correct because TCP is designed for applications that require a reliable Transport layer mechanism and TCP is a connection-oriented, stateful, and reliable protocol. Answers A and C are incorrect because these are features of UDP and not TCP.