多项选择题 Which two states are the port states when RSTP has converged？（）

单项选择题 A network administrator needs to force a high-performance switch that is located in the MDF to become the root bridge for a redundant path switched network. What can be done to ensure that this switch assumes the role as root bridge（）。

单项选择题 Host1的用户想PING DSL调制解调器/路由器的192.168.1.254，ARP表如下图，Host1会怎么操作？（）