Learning OpenStack Networking - Third Edition

Physical server connections

The number of interfaces needed per host is dependent on the purpose of the cloud, the security and performance requirements of the organization, and the cost and availability of hardware. A single interface per server that results in a combined control and data plane is all that is needed for a fully operational OpenStack cloud. Many organizations choose to deploy their cloud this way, especially when port density is at a premium, the environment is simply used for testing, or network failure at the node level is a non-impacting event. When possible, however, it is recommended that you split control and data traffic across multiple interfaces to reduce the chances of network failure.