1. [单选题]What is the purpose of the spanning-tree algorithm in a switched LAN?
A. To provide a monitoring mechanism for networks in switched environments.
B. To manage VLANs across multiple switches.
C. To prevent switching loops in networks with redundant switched paths.
D. To segment a network into multiple collision domains.
E. To prevent routing loops in networks.
2. [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
3. [单选题]路由器当前的模式为“端口模式”，要退回到“特权模式”，应该使用的快捷键(shortcut key)为（）
A. ctrl+b
B. ctrl+z
C. ctrl+c
D. ctrl+p
4. [单选题]当拓扑信息完成交换，相邻路由器具有相同的LSDB时，下列哪项OSPF邻居状态是希望得到的()
A. 2-WAY
B. FULL
C. Exchange
D. Loading
5. [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将内部地址一对一静态映射到内部全局地址
D. CISCO路由器缺省使用了静态NAT
6. [单选题]把访问权限表应用到路由器端口的命令是：()
A. permit access-list 101 out
B. ip access-group 101 out
C. apply access-list 101 out
D. access-class 101 out
7. [单选题]Assuming you build networks to exact specifications, what is the recommended maximum length a 10BaseT cable can be before it has to be segmented or repeated?
A. 100 meters
B. 100 feet
C. 100 yards
D. 200 meters
E. None of the above
8. [多选题]With regard to Ethernet media access methods, which of the following are true?(Choose all that apply.)
A. A device waits for an electronic signal before transmitting.
B. A device listens and waits until the media is not busy before transmitting.
C. All devices on an Ethernet segment see data that passes on the network medium.
D. Only the sender and the receiver devices see data that passes on the network medium.
E. Ethernet networks allow you to configured devises with higher transmission priority.
9. [单选题]A receiving host has failed to receive all of the segments that it should acknowledge.What can the host do to improve the reliability of this communication session?
A. Start a new session using UDP
B. Obtain a new IP address from the DHCP server
C. Use a different source port for the session
D. Decrease the sequence number
E. Decrease the window size
10. [单选题]Cisco IOS命令ip nat inside source static 10.1.1.5 172.35.16.5的作用是什么()
A. 为所有的外部NAT创建一个全局的地址池
B. 为内部的静态地址创建动态的地址池
C. 它为所有内部本地PAT创建创建了动态源地址转换
D. 为内部本地地址和内部全局地址创建一对一的映射关系
