DNS Interview Questions

 

DNSInterviewQuestionsandAnswer1.Secureservicesinyournetworkrequirereversenameresolutiontomakeitmoredifficulttolaunchsuccessfulattacksagainsttheservices.Tosetthisup,youconfigureareverselookupzoneandproceedtoaddrecords.Whichrecordtypesdoyouneedtocreate?2.WhatisthemainpurposeofaDNSserver?3.SOArecordsmustbeincludedineveryzone.Whataretheyusedfor?4.Bydefault,ifthenameisnotfoundinthecacheorlocalhostsfile,whatisthefirststeptheclienttakestoresolvetheFQDNnameintoanIPaddress?5.WhatisthemainpurposeofSRVrecords?6.Beforeinstallingyourfirstdomaincontrollerinthenetwork,youinstalledaDNSserverandcreatedazone,namingitasyouwouldnameyourADdomain.However,aftertheinstallationofthedomaincontroller,youareunabletolocateinfrastructureSRVrecordsanywhereinthezone.Whatisthemostlikelycauseofthisfailure?7.WhichofthefollowingconditionsmustbesatisfiedtoconfiguredynamicDNSupdatesforlegacyclients?8.Atsomepointduringthenameresolutionprocess,therequestingpartyreceivedauthoritativereply.Whichfurtheractionsarelikelytobetakenafterthisreply?9.Yourcompanyusestendomaincontrollers,threeofwhicharealsousedasDNSservers.YouhaveonecompanywideAD-integratedzone,whichcontainsseveralthousandresourcerecords.Thiszonealsoallowsdynamicupdates,anditiscriticaltokeepthiszoneup-to-date.Replicationbetweendomaincontrollerstakesupasignificantamountofbandwidth.Youarelookingtocutbandwidthusageforthepurposeofreplication.Whatshouldyoudo?10.YouareadministeringanetworkconnectedtotheInternet.Youruserscomplainthateverythingisslow.PreliminaryresearchoftheproblemindicatesthatittakesaconsiderableamountoftimetoresolvenamesofresourcesontheInternet.Whatisthemostlikelyreasonforthis?Answers………………….1.PTRRecords2.DNSserversareusedtoresolveFQDNhostnamesintoIPaddressesandviceversa3.SOArecordscontainaTTLvalue,usedbydefaultinallresourcerecordsinthezone.SOArecordscontainthee-mailaddressofthepersonwhoisresponsibleformaintainingthezone.SOArecordscontainthecurrentserialnumberofthezone,whichisusedinzonetransfers.4.PerformsarecursivesearchthroughtheprimaryDNSserverbasedonthenetworkinterfaceconfiguration5.SRVrecordsareusedinlocatinghoststhatprovidecertainnetworkservices.6.Thezoneyoucreatedwasnotconfiguredtoallowdynamicupdates.ThelocalinterfaceontheDNSserverwasnotconfiguredtoallowdynamicupdates.7.Thezonetobeusedfordynamicupdatesmustbeconfiguredtoallowdynamicupdates.TheDHCPservermustsupport,andbeconfiguredtoallow,dynamicupdatesforlegacyclients.8.Afterreceivingtheauthoritativereply,theresolutionprocessiseffectivelyover.9.ChangethereplicationscopetoallDNSserversinthedomain.10.DNSserversarenotcachingreplies..Localclientcomputers arenotcachingreplies…Thecache.dnsfilemayhavebeencorruptedontheserver.