1. [单选题]路由器下，由一般用户模式进入特权用户模式的命令是：（）
A. enable
B. config
C. interface
D. router
2. [单选题]The 201.145.32.0 network is subnetted using a /26 mask. How many networks and IP hosts per network exists using this subnet mask?
A. 4 networks and 64 hosts
B. 64 networks and 4 hosts
C. 4 networks and 62 hosts
D. 62 networks and 2 hosts
E. 6 network and 30 hosts
3. [单选题]The network administrator has configured port security on a Ezonexam switch. Why would a network administrator configure port security on this Ezonexam device?
A. To prevent unauthorized hosts from getting access to the LAN
B. To limit the number of Layer 2 broadcasts on a particular switch port
C. To prevent unauthorized Telnet or SSH access to a switch port
D. To prevent the IP and MAC address of the switch and associated ports
E. None of the above
