单项选择题
Refer to the exhibit. Look at the command output. What can you use to prevent this behavior？（）
A.UDLD B.spanning-tree loopguard C.VTP mode transparent D.switchport mode desirable
问答题 PQmajordisadvantage？
问答题 Inbroadcastnetworkthefirstadjofospfis2-way？why？thisquestionwillgiveyouapicture.
单项选择题 Refer to the exhibit. Look at the command output. Assume that there is no other path，and the configuration is correct. What would be the consequences of this situation？（）
