1. [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
2. [单选题]在地址转换中，()用来规定哪些数据包需要进行地址转换
A. 在线用户表
B. 访问控制列表
C. MAC地址表
D. 路由表
3. [单选题]路由器上“水平分割”的功能是：()
A. 分离端口
B. 阻止路由环路
C. 简化配置
D. 方便故障处理
