what is four ospf area type？

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

Local Preference？

QoS Mechanisms：問在部署QoS中要用的3個mechanisms是什么？

four switches， which one will be root switch.（no pic）.

What is the three main step of using the QoS feature with MQC command line interface？

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?（）

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

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

如何實(shí)現(xiàn)擁塞避免？