【正文】
靜態(tài)VLAN模式。命令D是將當(dāng)前端口分配給vlan 1。答案:D● 在以太網(wǎng)協(xié)議中使用1堅(jiān)持型監(jiān)聽(tīng)算法的特點(diǎn)是 (62) 。(62)A.能及時(shí)搶占信道,但增加了沖突的概率 B.能即使搶占信道,并減少了沖突的概率 C.不能及時(shí)搶占信道,并增加了沖突的概率 D.不能及時(shí)搶占信道,但減少了沖突的概率試題解析:1堅(jiān)持CSMA的做法是:當(dāng)一個(gè)站點(diǎn)要發(fā)送數(shù)據(jù)幀時(shí),它就監(jiān)聽(tīng)媒體,判斷當(dāng)前時(shí)刻是否有其他站點(diǎn)正在傳輸數(shù)據(jù)。如果媒體忙的話,該站等待直至媒體空閑。一旦該站檢測(cè)到媒體空閑,它就立即發(fā)送數(shù)據(jù)幀。如果產(chǎn)生沖突,則等待一個(gè)隨機(jī)時(shí)間再監(jiān)聽(tīng)。之所以叫“1堅(jiān)持”,是因?yàn)楫?dāng)一個(gè)站點(diǎn)發(fā)現(xiàn)媒體空閑的時(shí)候,它傳輸數(shù)據(jù)幀的概率是1。1堅(jiān)持CSMA的優(yōu)點(diǎn)是:只要媒體空閑,站點(diǎn)就立即發(fā)送;它的缺點(diǎn)在于:假如有兩個(gè)或兩個(gè)以上的站點(diǎn)有數(shù)據(jù)要發(fā)送,沖突就不可避免。答案:A● 在千兆以太網(wǎng)物理層標(biāo)準(zhǔn)中,采用長(zhǎng)波(1300nm)激光信號(hào)源的是 (63) 。(63)A.1000BASESXB.1000BASELX C.1000BASECXD.1000BASET試題解析:即使記不得編號(hào)也沒(méi)關(guān)系。L——Long(長(zhǎng)波),S——Short(短波),C——Copper(銅),T——twistedpair(雙絞線)。答案:B● 以太網(wǎng)的最大幀長(zhǎng)為1518字節(jié),每個(gè)數(shù)據(jù)幀前面有8個(gè)字節(jié)的前導(dǎo)字段,對(duì)于10BASE5網(wǎng)絡(luò)來(lái)說(shuō),發(fā)送這樣的幀需要多少時(shí)間? (64) (64)A.B. C.D.試題解析:+(8+1518)*8/10M≈。答案:C● WLAN采用擴(kuò)頻技術(shù)傳輸數(shù)據(jù),下面哪一項(xiàng)不是擴(kuò)頻技術(shù)的優(yōu)點(diǎn)? (65) (65)A.對(duì)無(wú)線噪聲不敏感B.占用的帶寬小 C.產(chǎn)生的干擾小D.有利于安全保密試題解析:既然是擴(kuò)頻,當(dāng)然不會(huì)減小帶寬占用。答案:B● 建立一個(gè)家庭無(wú)線局域網(wǎng),使得計(jì)算機(jī)不但能夠連接因特網(wǎng),而且WLAN內(nèi)部還可以直接通信,正確的組網(wǎng)方案是 (66) 。(66)A.AP+無(wú)線網(wǎng)卡B.無(wú)線天線+無(wú)線MODEM C.無(wú)線路由器+無(wú)線網(wǎng)卡D.AP+無(wú)線路由器試題解析:常識(shí)。答案:C● 計(jì)算機(jī)系統(tǒng)中廣泛采用了RAID技術(shù),在各種RAID技術(shù)中,磁盤(pán)容量利用率最低的是 (67) 。(67)A.RAID0B.RAID1C.RAID3D.RAID5試題解析:RAID1是鏡像模式,磁盤(pán)容量利用率僅為50%,最低。答案:B● 以下協(xié)議中屬于傳輸層的是 (68) 。(68)A.UCPB.UDPC.TDPD.TDC試題解析:常識(shí)。答案:B● 下圖為某系統(tǒng)集成項(xiàng)目的網(wǎng)絡(luò)工程計(jì)劃圖,從圖可知項(xiàng)目最短工期為 (69) 天,至少需要投入 (70) 人才能完成該項(xiàng)目(假設(shè)每個(gè)技術(shù)人員均能勝任每項(xiàng)工作)。(69)A.5B.7C.8D.10(70)A.2B.4C.6D.8試題解析:(69)常識(shí)。(70)主機(jī)安裝需要2人2天,廣域網(wǎng)絡(luò)安裝需要2人3天,合起來(lái)正好是2人5天。再結(jié)合上局域網(wǎng)絡(luò)安裝的4人5天,總共是6人5天。答案:(69)A(70)C● Serialization delay and (71) delay are the two ponents of network delay that are improved by increasing bandwidth. Serialization delay, . the amount of time it takes to put the (72) on the wire, and queuing delay (depth of the queue) are improved by increasing the (73) from a 128kbps circuit to a T1. However, three other ponents of delay, routing/switching delay, distance delay, and protocol delay are ponents that can not be positively affected by an (74) in bandwidth. If the circuits are not overutilized, then increasing the bandwidth to improve the (75) of the application will only result in an increased bandwidth with no positive effects on performance.(71)A.bufferingB.queuingC.receivingD.timing(72)A.electricityB.digitalC.dataD.variable(73)A.memoryB.cacheC.bandwidthD.delay(74)A.increaseB.decreaseC.maintenanceD.extension(75)A.capabilityB.costC.a(chǎn)mountD.performance試題解析:學(xué)好英語(yǔ),一切都很簡(jiǎn)單。答案:(71)B(72)C(73)C(74)A(75)D18 / 18