Briefing Huawei Knowledge

Which of the following may cause this?

The network administrator attempts to add interface G0/0/1 on Switch A to Eth-trunk 1, however the command
fails.
Which of the following may cause this?

A.
The interface is operating in half-duplex mode.

B.
The interface has been shutdown.

C.
The interface is already associated with another Eth-trunk.

D.
The interface is an access port.

Explanation: