Introduction
The OpenStack Neutron provides you with various ways to implement virtual networks in order to connect the virtual machine instances started by tenants. At a broad level, these network types can be classified in two categories—networks based on VLANs and networks based on overlays or tunnels.
In the case of overlay networks, the virtual switch on the Hypervisor encapsulates the data packets from the VM in an IP packet and sends it to the destination Hypervisor. The virtual switch on the destination Hypervisor then de-encapsulates and delivers the data packet to the destination VM instance. The encapsulation process adds an identifier or a tunnel key to mark and identify the packets belonging to different virtual networks.
The OpenStack Neutron provides two ways to implement the overlay or tunnel-based virtual networks, namely VXLAN and GRE. In this chapter, we will see how to implement virtual networks using overlays and the ML2 plugin in Neutron.
In order to implement...
