问题：

[多选] Which of the following characteristics describe the Root Guard feature？（Choose all that apply.）（）

A . The port must be put into forwarding state manually after root-inconsistent state has beencorrected
B . A Root Guard port receiving superior BPDU goes into a root-inconsistent state
C . A Root Guard port receiving inferior BPDU goes into a root-inconsistent state
D . While the port is in a root-inconsistent state no user data is sent across that port
E . The port returns to a forwarding state if inferior BPDUs stop
F . It should be applied to all switch port