Configuring the Switch to Add Double VLAN Tags to Untagged Packets

Procedure

1. Run system-view

   The system view is displayed.

2. Run vlan vlan-id

   An outer VLAN is created.

3. Run quit

   Return to the system view.

4. Run interface interface-type interface-number

   The interface view is displayed.

5. Run port link-type hybrid

   The link type of the interface is set to hybrid.

   By default, the link type of an interface on the S2720-EI, S5720I-SI, S5720-LI, S5735-L, S5735S-L, S5735S-L-M, S5720S-LI, S5720S-SI, S5720-SI, S5735-S, S5735S-S, S5735-S-I, S5730S-EI, S5730-SI, S6720-LI, S6720S-LI, S6720S-SI, and S6720-SI is negotiation-auto, and the link type of an interface on other models is negotiation-desirable.

6. Run qinq vlan-translation enable

   VLAN translation is enabled on the interface.

7. Run port hybrid untagged vlan vlan-id

   The interface is added to the outer VLAN.

8. Run port vlan-stacking untagged stack-vlan vlan-id1 stack-inner-vlan vlan-id2

   The interface is configured to add double VLAN tags to untagged packets.

   

   To enable an interface to add double VLAN tags to an untagged packet, you need to set the link type of the interface to hybrid, and add the interface to the VLAN specified by stack-vlan in untagged mode on the S6720S-SI, S6720S-LI, S6720-SI, S6720-LI, S5730-SI, S5730S-EI, S5720S-SI, S5720S-LI, S5720-SI, S5720-LI, S5720I-SI, S2720-EI. On other devices, you need to set the link type of the interface to hybrid or trunk, and add the interface to the VLAN specified by stack-vlan.

   If the PVID of the interface is not VLAN 1, restore the PVID to VLAN 1 before running the port vlan-stacking untagged command.

   The port vlan-stacking untagged command actually configures a VLAN assignment mode. On the S2720-EI, S5720I-SI, S5720-LI, S5735-L, S5735S-L, S5735S-L-M, S5720S-LI, S5720S-SI, S5720-SI, S5735-S, S5735S-S, S5735-S-I, S5730S-EI, S5730-SI, S6720-LI, S6720S-LI, S6720S-SI, and S6720-SI, different VLAN assignment modes are in the following descending order of priority: interface-based VLAN assignment > voice VLAN include-untagged > MAC address-based VLAN assignment > IP subnet-based VLAN assignment > port vlan-stacking untagged > protocol-based VLAN assignment > interface-based VLAN assignment. On other models, different VLAN assignment modes are in the following order of priority: policy-based VLAN assignment > voice VLAN include-untagged > MAC address-based VLAN assignment > IP subnet-based VLAN assignment > protocol-based VLAN assignment > interface-based VLAN assignment.