单项选择题
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
单项选择题 Hosts on the same VLAN can communicate with each other but are unable to communicate with hosts on different VLANs. What is needed to allow communication between VLANs（）。
单项选择题 There are no boot system commands in a router configuration in NVRAM.What is the fall back sequence that router will use to find an ios during reload？（）
单项选择题 根据下图，Switch1刚刚完成重启，并完成上电自检。HostA发送它的第一个侦到HostC，交换机首先会对switching table做什么操作（）