计算机网络-第二次平时考试

计算机网络平时考试试题（带答案）

一、选择题

1．In the Ethernet frame structure, the Data field carries the ( ).

datagram

2．The units of data exchanged by a link-layer protocol are called ( ).

A. Frames

B. Segments

C. Datagrams

D. bit streams

3．The SYN segment is used for ( ).

connection setup flow control

congestion control a TCP connection

4．The ( ) is a worldwide computer network, that is, a network that interconnects millions of computing devices throughout the world.

A. Internet

B. Intranet

C. switch net

D. television net

5．The units of data exchanged by a link-layer protocol are called ( ).

A. Frames

B. Segments

C. Datagrams

D. bit streams

6．In Address：（）indicates “host name”.

A. www

B. uzz

C. edu

D. cn

7. In the following options, which belongs to the network core ( )

A. end systems

B. routers

C. clients

D. servers

8．The Internet’s connection-oriented service has a name, it is ( ).

B. UDP IP

9．There are two fundamental approaches to building a network core, ( ) and packet switching.

A. electrical current switching

B. circuit switching

C. data switching

D. message switching

10．A ( ) protocol is used to move a datagram over an individual link.

A. application-layer

B. transport-layer

C. network-layer

D. link-layer 11．Services provided by transport layer include ( ).

and FTP and IP and UDP

12．IP addressing assigns an address to the network address for this network is ( ).

B. .198.250

C.

D. belongs to ( ).layer

link D. physical

14．Which of the following is correct ( )

A. No two adapters have the same MAC address.

B. MAC broadcast address is FF-FF-FF-FF-FF-FF.

C. A portable computer with an Ethernet card always has the same MAC address, no matter where the computer goes. ( ).

D. All of the above

15．How many bits specify the IP protocol version in a datagram ( ).

bit bits bits bits

16．In the following applications, which one is a loss-tolerant application

A E-mail

B file transfer

C instant messaging

D real-time audio 18．The Internet mail system has three components which they are ( ).

agent, SMTP, POP3 , POP3, IMAP

agent, SMTP, IMAP agent, SMTP, mail server

19．DNS means ( ).

Name System National System

Name System National System

20．“24” where the /24 notation, some times known as a ( ).

A. Subnet mask

B. Networking address

C. Host address

D. None of above 21．Which of the following is not intra-AS routing protocol ( )

A. RIP

B. OSPF

C. IGRP

22．IP addressing assigns an address to the network address for this network is ( ).

B. .198.250

C.

D. Data-grams are rarely larger than ( ).

A. 1500 bytes

B. 65535 bytes bytes bytes

24．Which of the following is correct ( )

A. No two adapters have the same MAC address.

B. MAC broadcast address is FF-FF-FF-FF-FF-FF.

C. A portable computer with an Ethernet card always has the same MAC address, no matter where the computer goes.

D. All of the above

25．Which of the following is not belonging to channel partitioning protocols ( )

D. TDM

26. MAC address is ( ) bits long.

.48 C

27．The Internet’s connection-oriented service has a name, it is ( ).

IP

28．In the LAN, ( ) protocol dynamically assign IP addresses to hosts.

29．Which layer provides host-to-host services ( ).

A. transport

B. network

C. data link

D. physical 30．DHCP protocol is a four-step p rocess: ①DHCP request. ②DHCP ACK. ③DHCP server discovery. ④DHCP server offer(s). The correct sequence is ( )

A.①②③④

B.③②①④

C.③④①②

D.①④③②31．In the Ethernet frame structure, the CRC field is ( ) bytes.

B.4

32．Transport-layer protocols run in ( ).

system

33．The maximum amount of data that can be grabbed and placed in a segment is limited by the( ).

A. Maximum segment size (MSS)

B. MTU

C. Checksum

D. Sequence number 34．The internet’s network layer provides a single service----that is ( ).

A. Reliable data transfer

B. Flow control

C. Congestion control

D. Best-effort-service 35．There are 6 flag fields. Which one is to indicate that the receiver should pass the data to the upper layer immediately ( )

A. PSH

B. URG

C. ACK

D. RST

36．ICMP is used for ( ).

A. Reliable data transfer

B. Error reporting

C. Flow control control

37．The FIN segment is used for ( ).

A. TCP connection setup

B. TCP flow control

C. TCP congestion control

D. Closing a TCP connection

38．A transport-layer protocol provides for logical communication between ( ).