If the DHCP Option 82 field defined on the switch contains only one VLAN ID and specifies the inner VLAN ID value, the switch sets the inner VLAN ID of user packets to 4096. Different carriers process invalid VLAN IDs in the DHCP Option 82 field in different ways. On a network, if the BRAS connected to the switch has specific requirements for invalid inner VLAN IDs in the DHCP Option 82 field, configure the Option 82 format that does not contain the inner VLAN ID.
        To configure the Option 82 format, run the dhcp option82 format user-defined text command in the system view or interface view.