問一個怎么樣的屬性，能讓路由不通告給任何的peer？

什么問題導致SERVER VTP密碼跟替他交換機VTP密碼不匹配？

As a CCNA candidate,you must have a firm understanding of the IPv6 address structure.Refer to IPv6 address,could you tell me how many bits are included in each filed?（）

The Frame Relay network in the diagram is not functioning properly.What is the cause of the problem?（） 

what is the disadvantage of policing？

Refer to the exhibit.Which statement describes DLCI 17?（）

Refer to the exhibit.What is the meaning of the term dynamic as displayed in the output of the show frame-relay map command shown？（）

What field in IP packet is used for classification by QOS？

Which of the following describes the roles of devices in a WAN?（）

When upgrading the IOS image,the network administrator receives the exhibited error message.What could be the cause of this error?（）