单项选择题
A.ping
B.dig
C.nbtstat
D.arp
单项选择题 Anetworkadministratorofacompanyhasmanybranchlocationseachusingasubnetmaskof255.255.255.224.Whichofthefollowingdynamicroutingprotocolsshouldbeused？（）
单项选择题 Auserisunabletoconnecttothenetwork.Anetworktechnicianisabletodeterminethatthereisaproblemontheswitch.Allotherusersonthatswitchareabletoconnectsuccessfullytothenetwork.Whichofthefollowingisaprobablecause？（）
单项选择题 WhichofthefollowingprotocolswouldamultilayerswitchusetolearntheIPaddressofadirectlyconnecteddevice？（）