221.17.101.223/28 is an example of which kind of notation？（）

单项选择题WhichofthefollowingwilllistthedestinationMACaddresses？（）

A.ping
B.dig
C.nbtstat
D.arp

单项选择题Auserisunabletoconnecttothenetwork.Anetworktechnicianisabletodeterminethatthereisaproblemontheswitch.Allotherusersonthatswitchareabletoconnectsuccessfullytothenetwork.Whichofthefollowingisaprobablecause？（）

A.Switching loop is occurring on the switch.
B.Wrong subnet mask on the switch.
C.Incorrect SNMP settings on the switch.
D.Port is misconfigured on the switch.

单项选择题Anetworkadministratorofacompanyhasmanybranchlocationseachusingasubnetmaskof255.255.255.224.Whichofthefollowingdynamicroutingprotocolsshouldbeused？（）

A.IPv6
B.RIP
C.IGRP
D.RIPv2

单项选择题WhichofthefollowingprotocolswouldamultilayerswitchusetolearntheIPaddressofadirectlyconnecteddevice？（）

A.ARP
B.BOOTP
C.Inverse-ARP
D.DNS

单项选择题Whichofthefollowingisthedefaultportfortelnet？（）

A.20
B.21
C.22
D.23