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 Ezonexam network administrator needs to a switch named VE1 to become the root bridge for a redundant path switched network. What can be done to ensure that VE1 will always assume the role as the root bridge?
A. Assign the switch a higher MAC address than the other switches in the network have
B. Establish a direct link from the switch to all other switches in the network
C. Configure the switch full-duplex operation and configure the other switches for half-duplex operation
D. Configure the switch so that it has lower priority than other switches in the network
E. None of the above
3. [单选题]查看路由表的命令是：()
A. show interface
B. show run
C. show ip route
D. show table
4. [单选题]命令“ping127.0.0.1”的功能是（）
A. 测试网卡是否正常
B. 测试网关是否正常
C. 测试TCP/IP协议是否正常
D. 测试介质是否正常
5. [单选题]How many usable IP addresses can you get from a conventional Class C address?
A. 128
B. 192
C. 254
D. 256
E. 510
