Layer2 OpenVPN and OVS

in Redhat based distro you need to create and tap interface and ovs bridge by NetworkManager and nmcli command to make it permanently and usable by openvpn 

in ubuntu and netplan env you just need to create ovs and tap interface by netplan config like this :

network:

  version: 2

  bridges:

    br0:

      openvswitch: {}

      dhcp4: no

      dhcp6: no

      optional: true

      addresses:

      - 172.16.16.9/24

      interfaces:

      - tap0

  ethernets:

    tap0:

      optional: true

ovs-if-br0          2c814735-7796-44e4-b665-0f11e3e9b042  ovs-interface  br0

br0                 561f4800-cdff-4ee9-b8d3-37a5bc12414b  ovs-bridge     br0

ovs-port-br0        d32517b7-66c5-47a0-b4ef-24a7b027c009  ovs-port       br0

tap0                76c6e78b-13f4-43e4-b1cc-f77232ce41d4  tun            tap0