Learning OpenStack Networking - Third Edition

Flat networks

The flat_networks configuration option defines interfaces that support the use of untagged networks, commonly referred to as native or access VLANs. This option requires that a provider label is specified. A provider label is an arbitrary label or name that is mapped to a physical interface or bridge on the host. These mappings will be discussed in further detail later on in this chapter.

In the following example, the physnet1 interface has been configured to support a flat network:

flat_networks = physnet1 

Multiple interfaces can be defined using a comma-separated list:

flat_networks = physnet1,physnet2

Due to the lack of an identifier to segregate untagged traffic on the same interface, an interface can only support a single ...