1. [单选题]OSPF骨干区的区域编号为（）
A. 0.0.0.1
B. 255
C. 0.0.0.0
D. 255.255.255.255
2. [单选题]要把交换机的配置文件保存到tftp服务器，应使用的命令为（）
A. copy ios tftp
B. copy running-configt ftp
C. copy flash tftp
D. copy config tftp
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]You are given a PC, a router, and a cable. Select the correct combination that will allow you to log into router VE1 locally using a terminal emulation program such as HyperTerminal.
A. Connect the PC's COM port to the router's console port using a straight-through cable.
B. Connect the PC's COM port to the router's console port using a rollover cable.
C. Connect the PC's COM port to the router's Ethernet port using a straight-through cable.
D. Connect the PC's Ethernet port to the router's Ethernet port using a rollover cable.
E. Connect the PC's Ethernet port to the router's Ethernet port using a straight- through cable.
F. F. None of the above
5. [单选题]地址转换NAT的优点是()
A. 地址转换对于报文内容中含有有用的地址信息的情况很难处理
B. 地址转换可以缓解地地址短缺的问题
C. 地址转换不能处理IP报头加密的情况
D. 地址转换由于隐藏了内部主机地址，有时会使网络调试变得复杂
