What is the next state of initial in spanning-tree protocol？

Which of the following are key characteristics of PPP?（）

What is method list for configure aaa？

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

兩ebgp鄰居發(fā)路由過來 ，哪些屬性重置？

aaa架構(gòu)中哪個是要求用戶輸入用戶名和密碼？

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

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？

A network administrator is troubleshooting the OSPF configuration of routers R1 and R2.The routers cannot establish an adjacency relationship on their common Ethernet link.The graphic shows the output of the show ip ospf interface e0 command for routers R1 and R2.Based on the information in the graphic,what is the cause of this problem?（）