Physical server connections
The number of interfaces needed per host is dependent on the type of cloud being built and the security and performance requirements of the organization.
A single interface per server that results in a combined control and data plane is all that is needed for a fully functional OpenStack cloud. Many organizations choose to deploy their cloud this way, especially when port density is at a premium or the environment is simply used for testing. In production clouds, however, separate control and data interfaces are recommended.
For hosts using a single interface, all traffic to and from instances as well as internal OpenStack, SSH management, and API traffic traverses the same interface. This configuration ...