Virtual Extensible LAN (VXLAN)

With traditional Ethernet switches, we can support a little over 4,000 VLANs. The reason is, the VLAN field is 12 bits long. That's going to give us just over 4,000 VLANs. But in today's networks where we might have a data center with lots of virtualization and the need to isolate several virtual machines from other virtual machines, we could easily run out of VLANs. Well, the great news is Virtual Extensible LANs or VXLANs can come to the rescue. They let us have over 16 million different identifiers instead of just 4,000. And the way VXLANs can do that is by encapsulating our Layer 2 or even Layer 3 traffic and adding a VXLAN network identifier that's called a VNI. And this VNI field is 24 bits long. That's what gives us those 16 million VXLAN network identifiers. And those VXLANs can run over our existing physical network infrastructure. The existing physical network infrastructure is referred to as an underlay network. Here we see 12 different switches and they're physically…