OpenStack Networking (Neutron) lets you create networks and subnets, then connect instances and other services to them. This page summarizes the difference between provider networks and self-service networks.
For deployment-specific Neutron configuration, see the Kolla-Ansible networking reference.
Provider networks map directly to existing layer 2 networks in the infrastructure. They can use flat or VLAN segmentation, depending on the cloud’s configuration.
Cloud administrators generally create provider networks because they depend on physical network configuration. An administrator can make a provider network available to one or more projects through the cloud’s sharing and role-based access control policies.
Provider networks connect instances to the mapped layer 2 network. They do not provide Neutron routers or floating IP addresses by themselves.
Self-service networks let project users create networks without asking an administrator to configure a physical network for each one. They usually use an overlay technology such as VXLAN or GRE. The cloud administrator configures which network types and segmentation ranges are available; Neutron selects from that configured set when a project creates a network.
To reach an external network, a self-service network normally connects to a Neutron router. The router can provide source NAT for outbound traffic and can associate floating IP addresses with instances for inbound connections. DHCP and metadata services can also be provided to instances, subject to the cloud’s configuration.
Because Neutron routes traffic between self-service and external networks, the network nodes and agents must be configured to support that path.
| Network | Typical creator | Typical segmentation | Routing |
|---|---|---|---|
| Provider | Cloud administrator | Flat or VLAN | Not provided by the network itself |
| Self-service | Project user | VXLAN, GRE, or another configured tenant type | Uses a Neutron router for external connectivity |
The exact permissions and available network types depend on the cloud’s Neutron policy and configuration.