Overlay networks in a reference implementation of Neutron are ones that use either VXLAN or GRE to encapsulate virtual instance traffic between hosts. Instances connected to an overlay network are attached to the integration bridge and use a local VLAN mapped to that network, just like the other network types we have discussed so far. All instances on the same host are connected to the same local VLAN.
In this example, an overlay network has been created with Neutron auto-assigning a segmentation ID of 39.
No changes are needed on the physical switching infrastructure to support this network, as the traffic ...
