期中考試計(jì)算機(jī)網(wǎng)絡(luò)

1、Computer networkMidterm Examination Name:Student number: 100minI. Choice.1The ( ) is a worldwide computer network, that is, a network that interconnects millions of computing devices throughout the world. A Internet BIntranetCswitch net Dtelevision net2The units of data exchanged by a link-layer pro

2、tocol are called ( ).AFrames B SegmentsCDatagrams Dbit streams3( ) means that the switch must receive the entire packet before it can begin to transmit the first bit of the packet onto the outbound link.AStore-and-forward transmission BFDMCEnd-to-end connection DTDM4In the following options, which o

3、ne is not a guided(有線) media? ( )A twisted-pair wire B fiber opticsC coaxial cable D satellite5Delay does not include ( ).AProcess delay Bpropagation delay Ctransmission delay D control delay6. In the following options, which belongs to the network core? ( )Aend systems BroutersCclientsDservers7The

4、Internets connection-oriented service has a name, it is ( ).ATCP BUDPCTCP/IP DIP8There are two fundamental approaches to building a network core, ( ) and packet switching.Aelectrical current switching Bcircuit switchingCdata switching Dmessage switching9A ( ) protocol is used to move a datagram over

5、 an individual link.Aapplication-layerBtransport-layerCnetwork-layerDlink-layer10Which of the following protocols is not a link-layer protocol? ( )AEthernetBPPPCHDLCDIP11Consider CRC error checking approach, the four bit generator G is 1011, and suppose that the data D is 10101010, then the value of

6、 R is( ).A 010 B 100 C 011 D 11012The ARP protocol can translate ( ) into ( ). ( )A host name, IP address B host name, MAC addressC IP address, MAC address Dbroadcast address, IP address13In the following descriptions about MAC address, which one is not correct? ( )A The MAC address is the address o

7、f one nodes adapter.B No two adapters have the same MAC address.C The MAC address doesnt change no matter where the adapter goes.D MAC address has a hierarchical structure.14In CSMA/CD, the adapter waits some time and then returns to sensing the channel. In the following four times, which one is imp

8、ossible? ( )A0 bit times B512 bit times C1024 bit times D1028 bit times15The most common Ethernet technologies are 10BaseT and 100BaseT. “10” and “100” indicate( ).Athe maximum length between two adaptersBthe minimum length between two adaptersCthe transmission rate of the channelDthe transmission r

9、ate of the node16The principal components of PPP include but not( ).Aframing Bphysical-control protocol Clink-layer protocol Dnetwork-layer protocol17In the following four options, which service can not be provided by switch? ( )Afiltering Bself-learning Cforwarding Doptimal routing18In ( ) transmis

10、sion(s), the nodes at both ends of a link may transmit packets at the same time.Afull-duplex Bhalf-duplex Csingle-duplexDboth full-duplex and half-duplex20MAC address is ( ) bits long.A32 B48 C128 D6421The following protocols are belonging to multiple access protocols except for ( ).Achannel partiti

11、oning protocolsBrouting protocolsCrandom access protocolsDtaking-turns protocols22Which of the following is not belonging to channel partitioning protocols? ( )ACSMABFDMCCDMADTDM23( ) provides a mechanism for nodes to translate IP addresses to link-layer address.AIPBARPCRARPDDNS24A MAC address is a

12、( )address.Aphysical-layerBapplication-layer Clink-layerDnetwork-layer35Which of the following is correct? ( )ANo two adapters have the same MAC address.BMAC broadcast address is FF-FF-FF-FF-FF-FF.CA portable computer with an Ethernet card always has the same MAC address, no matter where the compute

13、r goes.DAll of the above36In the Ethernet frame structure, the Data field carries the ( ).AIP datagramBsegmentCframeDmessage37Ethernets multiple access protocol is ( ).ACDMABCSMA/CDCslotted ALOHADtoken-passing protocol38A switch is a( )device that acts on frame.Aphysical-layerBlink-layerCnetwork-lay

14、erDtransport-layer39What are the two most important network-layer functions in a datagram network? （ ）A. forwarding & routing B. forwarding & filteringC. routing & detecting D. routing & checking40A router forwards a packet by examining the value of a field in the arriving packets he

15、ader, and then using this value to index into the routers forwarding table, this value is? （ ）A. destination IP address B. source IP addressC. destination MAC address D. source MAC address41Which layer provides host-to-host services? （ ）A. transport network B. data link physical42IPV4 has a _ bit ad

16、dress? （ ）A. 48 16 B. 32 6443How many bits specify the IP protocol version in a datagram? （ ）A. 1 bit B. 2 bits C. 4 bits D. 8 bits44Data-grams are rarely larger than _?（ ）A. 1500 bytes B. 65535 bytes C. 500 bytes D. 1024 bytes45How does the TTL changed by one each time the datagram is processed by

17、a router? （ ）A. decrease B. increase C. no change D. always 046ICMP is used for_?（ ）A. Reliable data transferB. Error reportingC. Flow control D. Congestion control47, the network address for this network is_.（ ）A. 223.10.198.248 B. 223.10.198.250 C. 223.10.198.0 D.48A switch works in _ layer? （ ）A.

18、 NetworkingB. Data linkC. ApplicationD. Physical49The internets network layer provides a single service-that is _.（ ）A. Reliable data transferB. Flow controlC. Congestion controlD. Best-effort-service50Which of the following protocol is used for error reporting? （ ）A. ICMPB. TCPC. IPD. UDP51Which of

19、 the following is not a routing protocol? （ ）A. TCPB. RIPC. OSPFD. BGP52IP address is identifier for _. （ ）A. HostB. Router interfaceC. Both of above D. None of above5324”, where the /24 notation, sometimes known as a_. （ ）A. Subnet maskB. Networking addressC. Host addressD. None of above54IPV6 has

20、a _ bits address? （ ）A. 32B. 64C. 16D. 12855Which of the following is not intra-AS routing protocol? （ ）A. RIPB. OSPFC. IGRPD. BGP 56RIP is a kind of _ algorithm. （ ）A. DVB. LSC. Both of aboveD. Neither of A and B57OSPF is a kind of _ algorithm. （ ）A. DVB. LSC. Both of aboveD. Neither of A and B58The two important network-layer functions are _. （ ）A. multiplexing and d