1. [单选题]关于静态NAT，下面（）说法是正确的。
A. 静态NAT转换在缺省情况下24小时后超时
B. 静态NAT转换从地址池中分配
C. 静态NAT将内部地址一对一(one to one)静态映射到内部全局地址
D. CISCO路由器缺省使用了静态NAT
2. [单选题]两个VLAN之间要想通信，应该使用的设备是（）
A. 集线器
B. 二层交换机
C. 路由器
D. PC机
3. [单选题]When is a switched network that is running the Spanning Tree Protocol considered to be fully converged?
A. when all switches have the same BID as the root switch
B. when all switches have received the MAC address of each neighboring switch
C. when every enabled switch port has been assigned a unique identifier
D. when every operating switch port is in either the blocking or forwarding state
E. when all switches are in either client, server, or transparent mode
4. [单选题]OSI七层模型中，数据链路层(data link layer)的数据封装名称为（）
A. 比特
B. 帧
C. 包
D. 段
5. [单选题]The Ezonexam LAN is upgrading all devices to operate in full duplex. Which statement is true about full-duplex Ethernet in comparison to half-duplex Ethernet?
A. Full-duplex Ethernet uses two wires to send and receive. Half-duplex Ethernet uses one wire to send and receive
B. Full-duplex Ethernet consists of a shared cable segment. Half-duplex Ethernet provides a point-to-point link
C. Full-duplex Ethernet can provide higher throughout than can half-duplex Ethernet of the same bandwidth
D. Full-duplex Ethernet uses a loopback circuit to detect collisions. Half-duplex ethernet uses a jam signal
E. None of the above
6. [单选题]After working all night and successfully configuring a Cisco router for the Ezonexam network you save your changes on the startup config, reboot the router, and go out for a cigarette. When you return, none of your changes are active and the router boots to the initial configuration mode! Which of the choices below indicates the source of your problem?
A. Hardware failure in NVRAM prevents the router from loading the config
B. Startup-config in flash is corrupt and cannot be analyzed
C. Router configuration-register set to bypass startup configuration
D. Startup-config in NVRAM is corrupt and cannot be analyzed
E. None of the above
7. [单选题]You want to upgrade the Ezonexam LAN so that all ports operate in full duplex mode. Which statement is true about full-duplex Ethernet when comparing to half-duplex Ethernet?
A. Full-duplex Ethernet consists of a shared cable segment. Half-duplex provides a point-to-point link
B. Full-duplex Ethernet uses two wires to send and receive. Half-duplex Ethernet uses one wire to send and receive
C. Full-duplex Ethernet can provide higher throughput than can half-duplex Ethernet of the same bandwidth
D. Full-duplex Ethernet uses a loopback circuit to detect collisions. Half-duplex Ethernet uses a jam signal
E. None of the above
8. [单选题]在OSPF的DR/BDR选举过程中，在路由器有相同的接口优先级情况下，什么用于确定DR或BDR（）
A. 最高的OSPF进程ID
B. 最低的接口IP地址
C. 最低的接口开销
D. 路由器ID
9. [单选题]对于路由表，下列说法中正确的是：（）
A. 在缺省的情况下，如果一台路由器同时运行了RIP和OSPF两种动态路由协议，则在路由表中只会显示RIP发现的路由，因为RIP协议的优先级更高
B. 在缺省的情况下，如果一台路由器同时运行了RIP和OSPF两种动态路由协议，则在路由表中只会显示OSPF发现的路由，因为OSPF协议的优先级更高
C. 在缺省的情况下，如果一台路由器同时运行了RIP和OSPF两种动态路由协议，则在路由表中只会显示RIP发现的路由，因为RIP协议的花费值（metric）更小
D. 在缺省的情况下，如果一台路由器同时运行了RIP和OSPF两种动态路由协议，则在路由表中只会显示OSPF发现的路由，因为OSPF协议的花费值（metric）更小
10. [单选题]You need to decide on which trunking method to implement in the Ezonexam network. What is a characteristic of ISL and 802.1q frame. tagging in a switched LAN environment?
A. They are used to find the best path through a network.
B. They allow the exchange of filtering tables.
C. They specify different implementations of the Spanning-Tree Protocol.
D. They allow the exchange of routing tables
E. They provide inter-switch VLAN communication.
