1. [单选题]You need to decide on which trunking method to implement in the Ezonexam network. What is a characteristic of ISL and 802.1q frame. tagging in a switched LAN environment?
A. They are used to find the best path through a network.
B. They allow the exchange of filtering tables.
C. They specify different implementations of the Spanning-Tree Protocol.
D. They allow the exchange of routing tables
E. They provide inter-switch VLAN communication.
2. [单选题]OSPF的度量值是什么()
A. 跳数
B. 接口开销
C. 矢量距离
D. 链路状态
3. [单选题]下列哪一个通配符掩码与子网172.16.64.0/27的所有主机匹配（）。
A. 255.255.255.0
B. 255.255.224.0
C. 0.0.0.31
D. 0.0.31.255
