2021年ccna考试题库课件.docVIP

QUESTION37

WhataretwocharacteristicsofRIPv2?(Choosetwo.)

A.classfulroutingprotocol

B.variable-lengthsubnetmasks

C.broadcastaddressing

D.manualroutesummarization

E.usesSPFalgorithmtocomputepath

Answer：BD

Explanation/Reference:

A：有类路由合同，错误

B：可变长度子网掩码，对的

C：采用广播地址更新，错误

D：手动路由汇总，对的

E:使用spf算法计算途径，错误。

QUESTION38

WhichtwoEthernetfiber-opticmodessupportdistancesofgreaterthan550meters?

1000BASE-CX

B.100BASE-FX

C.1000BASE-LX

D.1000BASE-SX

E.1000BASE-ZX

Answer：CE

Explanation/Reference:

A：最长距离25米

B：最长距离100米

C：最长距离3000米

D：最长距离550米

E：最长距离70千米

QUESTION39

Whattwothingswillarouterdowhenrunningadistancevectorroutingprotocol?(Choosetwo.)

A.Sendperiodicupdatesregardlessoftopologychanges.

B.Sendentireroutingtabletoallroutersintheroutingdomain.

C.Usetheshortest-pathalgorithmtothedeterminebestpath.

D.Updatetheroutingtablebasedonupdatesfromtheirneighbors.

E.Maintainthetopologyoftheentirenetworkinitsdatabase.

Answer：AD

Explanation/Reference:

考点：考查距离矢量路由合同特性

A：周期性更新，对的

B：发送整个路由表到整个路由域，错误，只发送给邻居

C：使用SPF算法，错误

D：依托邻居发送更新来更新路由表，对的

E：在数据库中维护整个网络拓扑。错误

Whichcommandshowsifanaccesslistisassignedtoaninterface?

A.showipinterface[interface]access-lists

B.showipaccess-listsinterface[interface]

C.showipinterface[interface]

D.showipaccess-lists[interface]

Answer：C

Explanation/Reference:

QUESTION42

Refertotheexhibit.WhichruledoestheDHCPserverusewhenthereisanIPaddressconflict?

A.Theaddressisremovedfromthepooluntiltheconflictisresolved.

B.Theaddressremainsinthepooluntiltheconflictisresolved.

C.OnlytheIPdetectedbyGratuitousARPisremovedfromthepool.

D.OnlytheIPdetectedbyPingisremovedfromthepool.

E.TheIPwillbeshown，evenaftertheconflictisresolved.

Answer：A

Explanation/Reference:

showipdhcpconflict命令可以查看哪些ip地址在使用上有冲突。

有冲突地址不再分派出去。

A：地址被删除直到冲突解决，对的

B:地址保存直到冲突解决，错误

C/D：答案片面。

E：当冲突解决后，地址会被显示。错误。

QUESTION44

Refert