Part 2: Using hardware VTEPS to integrate physical devices
These principals work great if every workload is virtualized and running on a hypervisor, however often there are still resources that cannot be virtualized because of various reasons. In this case it is extremely helpful if the ToR switches have the ability to provide the encapsulation and decapsulation of VXLAN packets, as this can provide high-speed connectivity between the physical and the virtual worlds.
Essentially the life of a packet is exactly the same as in a pure virtual environment, however this time there is a hypervisor and a virtual machine on the left side, while there is a bare-metal device and a physical switch on the right side. The tricky question now obviously is how the switch can actually learn which local ports should be part of which virtual networks and also the possible destinations within the virtual network.
This is been accomplished by the Open vSwitch Database (OVSDB), which is not really a protocol, but more a description about topology information that can be shared across different physical or virtual devices.
VMWare released NSX for vSphere 6.2.0 at the end of August 2015 and this was the first version of this NSX flavor to actually support OVSDB for the integration of hardware switches. In the following sections we demonstrate how a Juniper QFX5100 switch can be integrated into an existing NSX installation and be used for providing a gateway between the physical and the virtual world.