单项选择题
A.Forward Delay B.2倍Forward Delay C.Hello Time D.2倍Hello Time
A.0.5倍Forward Delay B.1倍Forward Delay C.2倍Forward Delay D.3倍Forward Delay
A.将选择Port1为根端口 B.将选择Port2为指定端口 C.将选择Port3为阻塞端口 D.将选择Port4为指定端口