单项选择题
A. Run the dnscmd /clearcache on Server3
B. Run the ipconfig /flushdns command on Server3
C. Decrease the Time-to-Live （TTL） on the Start of Authority （SOA） record of na.contoso.com to 15minutes
D. Increase the Retry Interval value on the Start of Authority （SOA） record of na.contoso.com to 15 minutes.
单项选择题 You need to capture the HTTP traffic to and from a server every day between 09:00 and 10:00. What should you do? （）
单项选择题 YourcompanyhasaDNSservernamedServer1.YourpartnercompanyhasaDNSservernamedServer2.YoucreateastubzoneonServer1.ThemasterforthestubzoneisServer2.Server2fails.Youdiscoverthatusersarenotabletoresolvenamesforthepartnercompany.YouneedtoensurethatusersareabletoresolvenamesforthepartnercompanyintheeventthatServer2fails.Whatshouldyoudo？（）
单项选择题 YourcompanyhasmultipleDNSserversinthemainoffice.YouplantoinstallDNSonamemberserverinabranchoffice.YouneedtoensurethattheDNSserverinthebranchofficeisabletoqueryanyDNSserverinthemainoffice，andyouneedtolimitthenumberofDNSrecordsthataretransferredtotheDNSserverinthebranchoffice.Whatshouldyoudo？（）