Enabling QinQ and configuring QinQ modes

By default, QinQ is disabled. When QinQ is enabled via the CLI, an operating mode is globally configured on the switch. Two QinQ modes are supported:

qinq mixedvlan: C-VLANs and S-VLANs are both supported, with regular switching/routing based on C-VLAN tags in the C-VLAN domain, while S-VLANs are used for QinQ tunneling through the provider network.
qinq svlan: C-VLANs are not supported on the device. All configured VLANs on the switch must be S-VLANs.

The following table shows how the various QinQ modes and operations impact VLAN configuration options on the switch.

Relationship of QinQ operating modes to VLAN environments
QinQ Operation	CLI Command	VLAN Options
QinQ disabled
No QinQ support(Default)	`no qinq`	Only regular VLAN commands are available. If QinQ is disabled, S-VLAN commands are not available.
QinQ enabled
QinQ mixed VLANmode	`qinq mixedvlan`	Both S-VLAN and regular VLAN commands (known as C-VLANs in a mixed vlan environment) are available.
QinQ S-VLAN mode	`qinq svlan`	No regular VLAN commands are available. All VLANs configured on the switch are S-VLANs only.