Usage Scenario
In a stacking scenario where BAS services are configured on a sub-interface and BAS user packets carry two VLAN tags in which VLAN IDs are specified using the user-vlan { { start-vlan-id [ end-vlan-id ] [ qinq start-pe-vlan [ end-pe-vlan ] ] } | any-other } command, BAS users cannot go online in any of the following situations:
- The outer VLAN ID for Layer 2 access is the same as the VLAN ID associated with the dot1q sub-interface configured using the vlan-type dot1q command on the same main interface.
- The outer VLAN ID for Layer 2 access is the same as the VLAN ID terminated by another dot1q VLAN tag termination sub-interface on the same main interface.
- A Layer 2 sub-interface configured with the encapsulation default command exists on the same main interface.
To address the preceding issues, run the vlan-miss to-cpu enable command to enable the corresponding board to send BAS user packets that carry two VLAN tags to the board's CPU in a stacking scenario. After this command is run, BAS users can go online properly.
Configuration Impact
After the vlan-miss to-cpu enable command is run in a slot view, the command takes effect for all interfaces on the board in the specified slot. When a user packet that carries two VLAN tags is sent to a user-side interface, if the outer VLAN ID in the user packet does not match any configuration on the interface, the packet is processed differently, depending on the packet's destination MAC address. If the packet's destination MAC address is the same as that of the current interface, the packet is sent to the CPU. Otherwise, the packet is discarded.
Precautions
This command is supported only on the admin VS.