多项选择题
A.OSPF
B.DHCP
C.SMTP
D.SNMP
E.RIP
单项选择题 WhichofthefollowingnetworkservicesisresponsibleformappingnamestoIPaddresses？（）
单项选择题 Whenoneconnectiontoahostfailsinafullmeshnetwork，whichofthefollowingistrue？（）
单项选择题 AuserconnectstothecompanysintranetserverviaaVPNconnectionfromasmalloffice/homeoffice（SOHO）usingthebroadbandservice.Oneday，theusercannotsuccessfullyconnecttotheVPNandreceivesanerrormessagethatstates"Usernameandpasswordareinvalidonthedomain."Whichofthefollowingshouldbedonetocorrectthisproblem？（）