test80C # diagnose sys checkused system.interface.name internal
entry used by table system.dhcp.server:id '1'
entry used by child table srcintf:name 'internal' of table firewall.policy:policyid '1'

查到後就先把它刪除吧
test80C # config firewall policy

test80C (policy) # delete 1

test80C (policy) # end

test80C # config system dhcp server

test80C (server) # delete 1

test80C (server) # end

在重下指令就可以收工了

test80C (global) # set internal-switch-mode interface

test80C (global) # end
Changing switch mode will reboot the system!
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