Configure networking on each node. See the basic information about configuring networking in the Networking service section of the Install Tutorials and Guides, depending on your distribution.
OpenStack network nodes contain:
Networking L2 agent
The L2 agent cannot be distributed and highly available. Instead, it must be installed on each data forwarding node to control the virtual network driver such as Open vSwitch or Linux Bridge. One L2 agent runs per node and controls its virtual interfaces.
For Liberty, you can not have the standalone network nodes. The Networking services are run on the controller nodes. In this guide, the term network nodes is used for convenience.