A.to prevent unauthorized Telnet access to a switch port
B.to limit the number of Layer 2 broadcasts on a particular switch port
C.to prevent unauthorized hosts from accessing the LAN
D.to protect the IP and MAC address of the switch and associated ports
E.to block unauthorized access to the switch management interfaces over common TCP ports

A.a switch with a trunk link that is configured between the switches
B.a router with an IP address on the physical interface that is connected to the switch
C.a switch with an access link that is configured between the switches
D.a router with subinterfaces configured on the physical interface that is connected to the switch

A.Flash，TFTPserver，ROM
B.Flash，NVRAM，ROM
C.ROM，NVRAM，TFTPserver
D.NVRAM，TFTPserver，ROM
E.TFTPserver，F(xiàn)lash，NVRAM

A.Switch1會添加192.168.23.4到switchingtable
B.Switch1添加192.168.23.12到switchingtable
C.Switch1添加000A 8A47.E612到switchingtable
D.Switch1添加000B DB95.2EE9到switchingtable

A.IR
B.DSSS
C.FHSS
D.DSSS and FHSS
E.IR，F(xiàn)HSS，and DSSS

A.permit all packets matching the first three octets of the source address to all destinations
B.permit all packets matching the last octet of the destination address and accept all source addresses
C.permit all packets from the third subnet of the network address to all destinations
D.permit all packets matching the host bits in the source address to all destinations
E.permit all packets to destinations matching the first three octets in the destination address

A.RIPng
B.OSPFv3
C.static
D.IS-ISfor IPv6

A.172.1.0.0/22
B.172.1.0.0/21
C.172.1.4.0/22
D.172.1.4.0/24  172.1.5.0/24  172.1.6.0/24  172.1.7.0/24
E.172.1.4.0/25  172.1.4.128/25  172.1.5.0/24  172.1.6.0/24  172.1.7.0/24

A.6to4 tunneling
B.VPN tunneling
C.GRE tunneling
D.ISATAP tunneling
E.PPP tunneling
F.Teredo tunneling

A.VTP is disabled on this switch.
B.The switch can create, change, and delete VLANs.
C.The switch learns VLAN information but does not save it to NVRAM.
D.The switch can create VLANs locally but will not forward this information to other switches.
E.The switch learns VLAN information and updates the local VLAN data base in NVRAM.