TCP/IP Internetworking Review Questions
(Answers in class notes or Modula A in book.)
A-1. What do we call messages at the data link layer?
a. Frames
b. Packets
c. Both of the above.
d. Neither a. nor b.
A-2. Which of the following is true?
a. Packets are encapsulated in frames.
b. Frames are encapsulated in packets.
c. Neither a. nor b.
A-3. During encapsulation, if layer N receives a message, which layer encapsulates the message?
a. N+1
b. N
c. N-1
d. Any of the above
e. None of the above
A-4. Which of the following does a router do first when it receives?
a. encapsulate
b. decapsulate
c. Neither a. nor b.
d. Both a. and b.
A-5. Which of the following is connectionless?
a. IP
b. UDP
c. TCP
d. Both a. and b.
A-6. Firewalls read the IP _____ field to know how to filter the packet’s data field.
a. protocol
b. TTL
c. Both of the above.
d. Neither a. nor b.
A-7. How many messages are sent in a TCP opening?
a. One
b. Two (the message and its acknowledgement)
c. Three
d. Four
e. Many
A-8. How many messages are sent in a normal TCP close?
a. One
b. Two (the message and its acknowledgement)
c. Three
d. Four
e. Many
A-9. How many messages are sent in an abrupt TCP close, i.e. in a Reset?
a. One
b. Two (the message and its acknowledgement)
c. Three
d. Four
e. Many
A-10. Mail servers use _____ port numbers in their source port number fields when they transmit.
a. ephemeral
b. registered
c. well-known
A-11. Which is more complex and so presents more opportunities for protocol abuse?
a. TCP
b. UDP
c. Both of the above.
d. Neither a. nor b.
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