Hi Hobbit,
You can use the local-telnet slave command to log in to the slave main control board and then use the display interface brief or display ip interface brief command to check whether the interface g0/0/0 is up or down.
<sysname> system-view
[sysname] diagnose
[sysname-diagnose] local-telnet slave
Info: Succeeded in entering local-telnet, and you can return to the user view wi
th Ctrl + K.
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For details, see https://support.huawei.com/hedex/hdx.do?docid=EDOC1100068394&id=local-telnet&lang=en