Networking is a virtual network service that provides a powerful API to define the network connectivity and IP addressing that devices from other services, such as Compute, use.
The Compute API has a virtual server abstraction to describe computing resources. Similarly, the Networking API has virtual network, subnet, and port abstractions to describe networking resources.
| Resource | Description |
|---|---|
| Network | An isolated L2 segment, analogous to VLAN in the physical networking world. |
| Subnet | A block of v4 or v6 IP addresses and associated configuration state. |
| Port | A connection point for attaching a single device, such as the NIC of a virtual server, to a virtual network. Also describes the associated network configuration, such as the MAC and IP addresses to be used on that port. |
You can configure rich network topologies by creating and configuring networks and subnets, and then instructing other OpenStack services like Compute to attach virtual devices to ports on these networks.
In particular, Networking supports each tenant having multiple private networks, and allows tenants to choose their own IP addressing scheme (even if those IP addresses overlap with those that other tenants use). The Networking service:
Enables advanced cloud networking use cases, such as building multi-tiered web applications and enabling migration of applications to the cloud without changing IP addresses.
Offers flexibility for the cloud administrator to customize network offerings.
Enables developers to extend the Networking API. Over time, the extended functionality becomes part of the core Networking API.
