VLAN pop on ingress and VLAN push on egress
Egress traffic from port 2 to the wire:
testpmd> flow create 2 transfer ingress pattern eth / vlan / ipv4 / udp / end actions of_pop_vlan / port_id id 0 / end
Ingress traffic from wire to port 2:
testpmd> flow create 0 transfer ingress pattern eth / ipv4 / udp / vxlan / end actions of_push_vlan ethertype 0x8100 / of_set_vlan_vid vlan_vid 3 / port_id id 2 / end