[单选题]当在一个接口上使用ipaccess-group99in命令时,以下哪条关于所引用访问控制列表的描述是正确的()
正确答案 :C
这个列表是编号型标准ACL,检查进入接口的数据包
[单选题]PPP工作在OSI的哪一层()
正确答案 :B
数据链路层
[单选题]路由器上,命令“show int s0”的显示结果为:Serial0 is up,line protocol is down出现该结果的可能原因是()
正确答案 :C
两端设备协议不一致
[单选题]OSI七层模型中,物理层的数据封装名称为()
正确答案 :A
比特
[多选题]默认情况下,IGRP衡量路径好坏时,考虑的因素为()
正确答案 :AD
带宽
延时
解析:AD
[多选题]属于私有IP段的是()
正确答案 :ABD
10.0.0.0-10.255.255.255
172.16.0.0-172.31.255.255
192.168.0.0-192.168.255.255
解析:ABD
[单选题]What is the purpose of the Spanning Tree Protocol (STP)?
正确答案 :D
To maintain a loop-free Layer 2 network topology
解析:解析:Explanation:
[多选题]The Ezonexam network administrator issues the ping 192.168.2.5 command and successfully tests connectivity to a host that has been newly connected to the network. Which protocols were used during the test? (Choose two)
正确答案 :AE
ARP
ICMP
解析:解析:Explanation:ARPfindsthehardwareaddressofahostfromaknownIPaddress.Here'showitworks:whenIPhasadatagramtosend,itmustinform.aNetworkAccessprotocol,suchasEthernetorTokenRing,ofthedestination'shardwareaddressonthelocalnetwork.(Ithasalreadybeeninformedbyupper-layerprotocolsofthedestination'sIPaddress.)IfIPdoesn'tfindthedestinationhost'shardwareaddressintheARPcache,itusesARPtofindthisinformation.ICMPworksattheNetworklayerandisusedbyIPformanydifferentservices.ICMPisamanagementprotocolandmessagingserviceproviderforIP.ItsmessagesarecarriedasIPdatagrams.RFC1256isanannextoICMP,whichaffordshosts'extendedcapabilityindiscoveringroutestogateways.Periodically,routeradvertisementsareannouncedoverthenetwork,reportingIPaddressesfortherouter'snetworkinterfaces.Hostslistenforthesenetworkinfomercialstoacquirerouteinformation.Aroutersolicitationisarequestforimmediateadvertisementsandmaybesentbyahostwhenitstartsup.
[多选题]The Ezonexam network administrator needs to determine what LAN devices to install on the Ezonexam network. What are two advantages of using Layer 2 Ethernet switches over hubs? (Choose two)
正确答案 :AD
Allowing simultaneous frame. transmissions
Filtering frames based on MAC addresses
解析:解析:Explanation:A:Ahalfduplexconnectioniswhereonlyonedevicecansendorreceiveatatime.Afullduplexconnectioniswherebothdevicescansendandreceiveatthesametime.Thus,ifyouhavea100Mbhalf-duplexconnection,onlysendingat100MbORreceivingat100Mbcanhappenatthesametime.Ifyouhavea100Mbfullduplexconnection,youcaneffectivelyget200Mboutofthelinkbecauseyoucouldbesending100Mbandreceiving100Mbatthesametime.D:SwitchesarecapableoffilteringframesbasedonanyLayer2fields.Forexample,aswitchcanbeprogrammedtoreject(notforward)allframessourcedfromaparticularnetwork.Becauselinklayerinformationoftenincludesareferencetoanupper-layerprotocol,switchesusuallycanfilteronthisparameter.Furthermore,filterscanbehelpfulindealingwithunnecessarybroadcastandmulticastpackets.
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