I want to present to you a nice YouTube series about VxLAN.

As you can find in my Juniper artikle V-Lan configuration the IEEE 802.1X standard enlarges the frame on Layer-2.
Even if at a first glance adding another 32Bit to every frame seems qute oversized, you will eventually run into its limits.
VxLAN is a way to wrap Layer-2 Traffic inside Layer-4 UDP traffic to surpass V-Lan’s limitations.