[TCP/IP] 9장 연습문제 - 객관식

1 : ICMP is a _________ layer protocol.

a. data link

b. transport

c. network

d. None of the choices are correct

 

2 : An ICMP message has _____ header and a variable-size data section.

a. a 16-byte

b. a 32-byte

c. an 8-byte

d. None of the choices are correct

 

3 : Which of the following is true about ICMP messages?

a. An ICMP error message may be generated for an ICMP error message.

b. An ICMP error message may be generated for each fragment.

c. An ICMP error message may be generated for a multicast datagram.

d. none is true

 

4 : Which of the following is true about ICMP messages?

a. An ICMP error message may be generated for an ICMP error message.

b. An ICMP error message may be generated only for the first fragment.

c. An ICMP error message may be generated for a multicast datagram.

d. none is true

 

5 : Which of the following is true about ICMP messages?

a. An ICMP error message may be generated for an ICMP error message.

b. An ICMP error message may be generated only for each fragment.

c. No ICMP error message will be generated for a datagram having a special address such as 127.0.0.0 or 0.0.0.0.

d. none is true

 

6 : If a host needs to synchronize its clock with another host, it sends a _______ message.

a. timestamp-request

b. source-quench

c. router-advertisement

d. None of the choices are correct

 

7 : The purpose of echo request and echo reply is to _______.

a. report errors

b. check node-to-node communication

c. check packet lifetime

d. None of the choices are correct

 

8 : In error reporting the encapsulated ICMP packet goes to _______.

a. the original sender

b. the receiver

c. a router

d. None of the choices are correct

 

9 : What field uniquely identifies the kind of ICMP message (for example, echo reply versus echo request)?

a. type

b. code

c. option ID

d. None of the choices are correct

 

10 : When the hop-count field reaches zero and the destination has not been reached, a _______ error message is sent.

a. destination-unreachable

b. time-exceeded

c. parameter-problem

d. None of the choices are correct

 

11 : When all fragments of a message have not been received within the designated amount of time, a _______ error message is sent.

a. source-quench

b. time-exceeded

c. parameter-problem

d. None of the choices are correct

 

12 : Errors in the header or option fields of an IP datagram require a _______ error message.

a. parameter-problem

b. source-quench

c. router-solicitation

d. None of the choices are correct

 

13 : A _______ can learn about network _______ by sending out a router-solicitation packet.

a. router, routers

b. router, hosts

c. host, routers

d. None of the choices are correct

 

14 : Who can send ICMP error-reporting messages?

a. routers

b. destination hosts

c. routers or destination hosts

d. None of the choices are correct

 

15 : One method to alert a source host of congestion is the _______ message.

a. redirection

b. echo-request

c. source-quench

d. None of the choices are correct

 

16 : A time-exceeded message is generated if _______.

a. the round-trip time between hosts is close to zero

b. fragments of a message do not arrive within a set time

c. the round-trip time between hosts is close to zero and fragments of a message do not arrive within a set time

d. None of the choices are correct

 

17 : To determine whether or not a node is reachable, _______ message can be sent.

a. an echo-reply

b. an echo-request

c. a redirection

d. None of the choices are correct

 

18 : In calculating the time difference between two clocks, a negative value indicates _______.

a. an invalid calculation

b. the source clock lags behind the destination clock

c. the destination clock lags behind the source clock

d. None of the choices are correc

 

19 : An IP datagram (datagram A) cannot reach its destination. An ICMP error message is sent to the source. The data field of the IP datagram (datagram B) that encapsulates the ICMP packet contains _______.

a. only the ICMP header

b. the ICMP header plus 8 bytes of datagram A

c. only datagram A

d. None of the choices are correct