By default, QinQ is disabled on the switch. To enable QinQ, the switch must be put into either in mixed VLAN mode or QinQ SVLAN mode by issuing one of the following commands from configuration mode on the CLI.
Syntax:
From configuration mode, globally enables QinQ mixed mode, an environment that supports both S-VLAN and C-VLAN traffic on the same device. This command requires a reboot to take effect. Default: Disabled.