1. [单选题]哪一个命令可以设置路由器特权用户的“明文密码”（）
A. enable password
B. password
C. enable secret
D. secret
2. [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
3. [多选题]The Ezonexam network administrator needs to determine what LAN devices to install on the Ezonexam network. What are two advantages of using Layer 2 Ethernet switches over hubs? (Choose two)
A. Allowing simultaneous frame. transmissions
B. Increasing the size of broadcast domains
C. Increasing the maximum length of UTP cabling between devices
D. Filtering frames based on MAC addresses
E. Decreasing the number of collision domains
4. [单选题]A Ezonexam PC has the IP address 172.16.209.10 /22. What is the subnet of this address?
A. 172.16.42.0
B. 172.16.107.0
C. 172.16.208.0
D. 172.16.252.0
E. 172.16.254.0
5. [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.
