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

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

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?（）

DHCP SERVER在給一個網(wǎng)段設(shè)置POOL時，該網(wǎng)段路由器接口地址能不能放入POOL，能why，不能why。

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

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

what is four ospf area type？

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

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

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