The Eth-Trunk interface is configured to work in LACP
mode and the bpdu bridge enable command is run.
Run the display interface brief command. It is
found that Eth-Trunk4 is Down, but all the member interfaces and peer
interfaces are in the Up state.
Undo the bpdu bridge enable command on Eth-Trunk4. Eth-Trunk4 then goes up.
On the CE12800 running V100R005
and later versions, after the bpdu
bridge enable command is run on an Eth-Trunk interface, BPDUs are not sent
to the CPU for processing, including the BPDU negotiation packets in LACP.
Therefore, the Eth-Trunk interface goes Down but the corresponding physical
interfaces remain Up. On the CE12800 running
V100R005 and later versions, the fault is rectified when the bpdu bridge enable command is not
configured on the Eth-Trunk interface.