HA Wan with 802.1q tagged virtual interface

  • Good day to all!

    So I`m planning a rather difficult pfsense setup in which I will require high availability (HA/failover) on my WAN interface.

    So I will create a virtual interface that will serve as WAN. That part is clear.

    I am also required to tag traffic going out of my WAN with a vlan. Creating vlan has become clear to me and I also understand that I will have to assign a parent interface to my vlan. The question is: If I have a virtual interface in a dual box failover setup for my wan and I want to tag the WAN with a vlan should I (or even would I be able to) set my virtual interface as vlan parent interface or should the real WAN interface be set as the vlan parent?

    Also, if this all is doable, can I do the same thing using bonding (2 physical interfaces) for WAN on both boxes?

    The setup would be as follows:
    bond two physical interfaces to create one logical interface to serve as WAN. Then create the failover scenario and have a virtual interface on top of the bonded logical interface. Then create a vlan and set its parent to the virtual interface.

    Thank You in advance!