Virtual Cloud Networks


On Compute Cloud@Customer, networking enables you to set up virtual versions of traditional network components.

When you work with Compute Cloud@Customer, one of the first steps is to set up a virtual cloud network (VCN) for your cloud resources.

The infrastructure that provides the necessary services to deploy cloud workloads is configured to operate within the network environment of your data center. During initialization, the infrastructure's core network components are integrated with your existing data center network design.

Virtual Network Interface Cards (VNICs)

The compute nodes in Compute Cloud@Customer have physical network interface cards (NICs). When you create a compute instance on one of the servers, the Networking service ensures that a VNIC is created on top of a physical interface, so that the instance can communicate over the network. Each instance has a primary VNIC that is automatically created and attached. The primary VNIC resides in the subnet you specify when creating the instance. It can't be removed from the instance.

A VNIC enables an instance to connect to a VCN and determines how the instance communicates with endpoints inside and outside of the VCN.

For more information, see Configuring VNICs.

IP Addressing

Instances use IP addresses for communication. Each instance has at least one private IP address and optionally one or more public IP addresses. A private IP address enables the instance to communicate with other instances inside the VCN. A public IP address enables the instance to communicate with hosts outside of the cloud network environment.

Certain types of resources are designed to be directly reachable from outside the secure Compute Cloud@Customer network environment, and therefore automatically come with a public IP address. For example: a NAT gateway. Other types of resources are directly reachable only if you configure them to be. For example: specific instances in your VCN. Direct public connectivity also requires that the VCN has an internet gateway and that the public subnet has correctly configured route tables and security lists.

For more information, see Managing Private IP Addresses and Managing Public IP Addresses.

DHCP Options

The Networking service uses DHCP to automatically provide configuration information to instances when they boot up. Although DHCP lets you change some settings dynamically, others are static and never change. For example, when you create an instance, either you specify the instance's private IP address or the system chooses one for you. Each time the instance boots up or you restart the instance's DHCP client, DHCP passes that same private IP address to the instance. The address never changes during the instance's lifetime.

The Networking service provides DHCP options to let you control certain types of configuration on the instances in your VCN. You can change the values of these options at your discretion, and the changes take effect the next time you restart an instance's DHCP client or reboot the instance.

For more information, see Working with DHCP Options.

Traffic Management Steering Policies

Steering Policies enable you to configure policies to serve intelligent responses to DNS queries, meaning different answers (endpoints) may be served for the query depending on the logic defined in the policy.

For more information, see Managing Traffic with Steering Policies