文档介绍：计网实验DNS--Data-Encapsulation-and-Frame-owrksLabsDNS,DataEncapsulationandFrameExaminationDNS,pletionofthislab,youwillbeableto:mands ,,pleaseratethefollowinginthescaleof1through5:Thedegreeofdifficulty:1=tooeasy;5=toodifficultThelearningexperience:1=learnednothing;5=learnedalotYourinterest:1=nointerest;5=highinterestTimeusedforthetask:inminutesTaskDifficulty(1—5)Learning(1—5)Interest(1—5)Time(min)ment:municatewitheachother,dataatthesendinghost flowsdowntheTCP/IPprotocollayersandisencapsulatedintoaprotocoldataunitatlowerlayer,,; theUDPsegmentisthenencapsulatedinanIPpacket,,,,,,mand,,pleasereadthelectures02,04-05,10, ProtocolLayersandDataEncapsulationAswehavediscussedinLecture02,isinter-worksbasedonTCP/. Whatarenamesfortheprotocoldataunits(PDUs)forlayer4,layer3,andlayer2protocolsinTCP/IPreferencemodelbyfillingthefollowform:    nameforPDUoflayer4protocols:  segment              nameforPDUoflayer3protocol:  packet                nameforPDUoflayer2protocol:  frame            Task1 DNSandnslookupAswediscussed,.ButIPaddressisnotuser-friendlyandthatiswhydomainnamew