Take the quiz (either here or use the PTP software) if you want to use the score to help you decide how much time to spend on this chapter. Appendix A, “Answers to the ‘Do I Know This Already?’ Quizzes,” found at the end of the book, includes both the answers and explanations. You can also find answers in the PTP testing software.
Table 14-1 ”Do I Know This Already?” Foundation Topics Section-to-Question Mapping
Caution The goal of self-assessment is to gauge your mastery of the topics in this chapter. If you do not know the answer to a question or are only partially sure of the answer, you should mark that question as wrong for purposes of the self-assessment.
Giving yourself credit for an answer you incorrectly guess skews your self-assessment results and might provide you with a false sense of security.
1. What is the primary purpose of the Internet Protocol?
a. Carry web pages across the Internet
b. Provide a consistent set of network abstractions across different kinds of physical links
c. Provide addressing for Internet-connected devices
d. Support a lot of different kinds of hosts
2. What must a receiver do to use the data contained in a fragmented packet?
a. Nothing; the data is usable the way it is received
b. Reassemble the original packet as it was transmitted
c. Request the sender retransmit the data in a smaller packet
d. Reconstruct the packet based on Forward Error Correction (FEC) data
3. What is TTL used for in IP networks?
a. Discard packets that have been forwarded too many times
b. Determine the age of data being carried through the network
c. Limit the number of encapsulations a router can place on a piece of data
d. Aid in the correct ordering of packets carried through the network
a. Address space that can be used independently of a single provider
b. IP address space a registry assigns to a customer
c. IP address space a provider assigns to a customer
d. IP address space publicly usable by anyone to connect to the Internet
5. Why do many network engineers consider NAT harmful?
a. NAT increases the size of packets being carried through the network.
b. Embedded IP addresses will not match the source and destination addresses in the header.
c. NAT breaks PMTUD.
d. NAT makes it too hard to find the actual host that transmitted a packet.
6. What does a connection-oriented transport service provide?
a. Flow control, error control, and limited-time delivery
b. Services for applications that can operate even if small amounts of data are dropped
c. Flow control, error control, and in-order data delivery
d. Services for transmitting data to multiple destinations
7. What process do TCP and QUIC both use to set up a session?
a. A nonce to identify the session
b. Three-way handshake
c. Two-way handshake
d. Cryptographic key exchange
8. How does QUIC speed up the second connection between two applications?
a. Skipping the three-way handshake
b. Using previously stored encrypted session information to skip the three-way handshake and key exchange
c. Skipping encryption key exchange
d. Using faster UDP packets to carry the handshake
9. What five things (tuples) are used to identify a flow uniquely?
a. Source address, destination address, protocol number, source port, destination port
b. Source address, destination address, flow label, source port, destination port
c. Source address, destination host identifier, protocol number, source port, destination port
d. Source host identifier, destination address, flow label, source port, destination port
10. Why is path maximum transmission unit discovery important?
a. To prevent IPv6 routers from fragmenting packets as they are carried through the network
b. To prevent IPv4 packets from being dropped because they take too long to transmit
c. To prevent IPv4 routers from fragmenting packets as they are carried through the network
d. To prevent dropping packets when a link with a smaller MTU than the packet is encountered