Guest network

The guest network is a network dedicated to instance traffic. Options for guest networks include local networks restricted to a particular node, flat, or VLAN-tagged networks, or virtual overlay networks made possible with GRE, VXLAN, or GENEVE encapsulation. For more information on guest networks, refer to Chapter 6, Building Networks with Neutron. Since guest networks provide connectivity to VMs, they can be considered part of the data plane.

The physical interfaces used for external and guest networks can be dedicated interfaces or ones that are shared with other types of traffic. Each approach has its benefits and drawbacks, and they are described in more detail later in this chapter. In the next few chapters, I will define networks and VLANs that will be used throughout the book to demonstrate the various components of OpenStack Networking. Generic information on the configuration of switch ports, routers, or firewalls will also be provided.