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

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?（） 

R1 will choose which path to reach 10.1.0.0？

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

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？（）

How should arouter that is being used in a Frame Relay network be configured to avoid split horizon issues from preventing routing updates?（）

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

what is four ospf area type？

QoS機制中的分類，采用ip數(shù)據(jù)包中的哪個字段？