Interaction with virtual ports
In PVLAN, Multicast protocols are decided to run only on the primary VLAN and not on secondary VLAN. Irrespective of not running IGMP/MLD on Secondary VLAN, the protocol code still needs to be PVLAN aware.
Once a packet comes into the protocol code from the VLS subsystem, the protocol needs to process packets from the primary as well as secondary VLANs in the Primary VLAN context and in the same manner, therefore the Protocol module does not need to be PVLAN aware. However, it needs to provide the inbound VLAN details to the underlying MTM layer (especially if inbound is secondary VLAN) for the correct replication of the packets by MTM.
Virtual Port (VPORT) is the solution proposed to extend the existing logical port LPORT_t variable to piggy-back this information to the underlying MTM layer.