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

當(dāng)將多個(gè)交換機(jī)加入到MST region當(dāng)中會(huì)發(fā)生什么（what happen）？

aaa架構(gòu)中哪個(gè)是要求用戶輸入用戶名和密碼？

A default Frame Relay WAN is classified as what type of physical network?（）

what is the disadvantage of policing？

什么是NAT？

Local Preference？

什么問題導(dǎo)致SERVER VTP密碼跟替他交換機(jī)VTP密碼不匹配？

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

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?（）