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1. [多选题]Ezonexam is migrating to a private IP addressing scheme. Which of the following describe the use of private IP addresses? (Choose two)
A. Addresses chosen by Ezonexam.com to communicate with the Internet.
B. Addresses that cannot be routed through the public Internet.
C. Addresses that can be routed through the public Internet.
D. A scheme to conserve public addresses.
E. Addresses licensed to enterprise or ISPs by an Internet registry organization.
2. [多选题]In which Spanning-Tree states does a switch port learn MAC addresses? (Select two)
A. Blocking
B. Listening
C. Forwarding
D. Learning
E. Relaying
3. [单选题]The Ezonexam network administrator has issued the "VTP password ezonexam" command on a Cisco device. What is the purpose of this command?
A. It allows two VTP servers to exists in the same domain, each configured with different passwords
B. It is the password required when promoting a switch from VTP client mode to VTP server mode
C. It is used to access the VTP server to make changes to the VTP configuration
D. It is used to validate the sources of VTP advertisements sent between switches
E. None of the above
4. [单选题]路由器上，命令“show int s0”的显示结果为：Serial0 is up,line protocol is down出现该结果的可能原因是（）
A. 端口处于关闭状态
B. 物理端口被烧毁
C. 两端设备协议不一致(inconsistency)
D. 路由表中无路由
5. [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
