第53題： 下面的描述中屬于工作區(qū)子系統(tǒng)區(qū)域范圍的是(   )。
A.實現(xiàn)樓層設(shè)各間之間的連接
B.接線間配線架到工作區(qū)信息插座
C.終端設(shè)備到信息插座的整個區(qū)域
D.接線間內(nèi)各種交連設(shè)備之間的連接
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第54題： 以下關(guān)于三層交換機(jī)的敘述中，正確的是(   )。
A.三層交換機(jī)包括二層交換和三層轉(zhuǎn)發(fā)，二層交換由硬件實現(xiàn)，三層轉(zhuǎn)發(fā)采用軟件實現(xiàn)
B.三層交換機(jī)僅實現(xiàn)三層轉(zhuǎn)發(fā)功能
C.通常路由器用在單位內(nèi)部，三層交換機(jī)放置在出口
D.三層交換機(jī)除了存儲轉(zhuǎn)發(fā)外，還可以采用直通交換技術(shù)
答案解析與討論：m.xiexiliangjiufa.com/st/404761213.html

第55題： IP數(shù)據(jù)報首部中IHL (Internet首部長度)字段的最小值為(   )。
A.5
B.20
C.32
D.128
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第57題： 如圖所示，Switch A通過Switch B和NMS跨網(wǎng)段相連并正常通信。SwitchA 與Switch B配置相似，從給出的Switch A的配置文件可知該配置實現(xiàn)的是( 1 )，驗證配置結(jié)果的命令是( 2 )。

（1）A．實現(xiàn)毫秒級鏈路故障感知并刷新路由表
B.能夠感知鏈路故降并進(jìn)行鏈路切換
C.將感知到的鏈路故障通知NMS
D.自動關(guān)閉故障鏈路接口并刷新路由表
（2）A.display nqa results
B.display bfd session all
C.display efm session all
D.display current-configuration|include nqa
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第58題： 如下圖所示，使用基本ACL限制FTP訪間權(quán)限，從給出的Switch的配置文件判斷可以實現(xiàn)的策略是(   )。

①PC1在任何時間都可以訪問FTP
②PC2在2018年的周一不能訪問FTP
③PC2在2018年的周六下午3點可以訪問FTP
④PC3在任何時間不能訪問FTP

A.①②③④
B.①②④
C.②③
D.①③④
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第59題： The TTL field was originally designed to hold a time stamp, which was decremented by each visited router. The datagram was ( 1 ) when the value became zero. However, for this scheme, all the machines must have synchronized clocks and must know how long it takes for a datagram to go from one machine to another. Today, this field is used mostly to control the ( 2 ) number of hops (routers) visited by the datagram. When a source host sends the datagram, it ( 3 ) a number in this field. Each router that processes the datagram decrements this number by 1. If this value, after being decremented, is zero, the router discards the datagram.This field is needed because routing tables in the Internet can become corrupted.A datagram may travel between two or more routers for a long time without ever getting delivered to the ( 4 ).This field limits the ( 5 ) of a datagram.
（1）A.received
B.discarded
C.rejected
D.tansferred
（2）A.maximum
B.minimum
C.exact
D.certain
（3）A.controls
B.transmits
C.stores
D.receives
（4）A.switch
B.router
C.source host
D.destination host
（5）A.lifetime
B.moving time
C.receiving time
D.transmitting time
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