单项选择题
What is the purpose of Spanning Tree Protocol?（）
A. to prevent routing loops B. to create a default route C. to provide multiple gateways for hosts D. to maintain a loop-free Layer 2 network topology E. to enhance the functions of SNMP
单项选择题 What is the function of the CSMA/CD algorithm in Ethernet technologies?（）
单项选择题 What value is primarily used to determine which port becomes the root port on each non root switch in a spanning-tree topology?（）
单项选择题 What is the purpose of the OSPF router ID in a OR/BOR election?（）
