Creating a Subnet using OpenStack CLI

Similar to the CLI commands to create a Network, the next recipe will explore the CLI command to create a Subnet. The key aspect of the CLI commands for Subnet creation is that a Network Name is a mandatory attribute.

Getting ready

You will need the following information to get started:

• The login credentials for SSH to a node where the Neutron client packages are installed
• A shell RC file that initializes the environment variables for CLI

How to do it…

The next set of steps will show you how to use Neutron CLI to create a Subnet:

1. Using the appropriate credentials, SSH into the OpenStack node where the Neutron client software packages are installed.
2. Source the shell RC file to initialize the environment variables required for the CLI commands as seen in the previous recipe.
3. The command to create a Subnet is neutron subnet-create and the mandatory arguments are the Network name and IP address range in the CIDR format. However, it is a good practice to specify a name for the Subnet. For simplicity, we will choose the Network, CookbookNetwork2, that was created earlier because it does not have any associated Subnet yet:
   
4. Now, when we execute the neutron net-list command, we will see that CookbookNetwork2 has an associated Subnet that we just created:
   
5. Users can view the list of Subnets using the neutron subnet-list command:
   

How it works…

When the user executes the neutron subnet-create command, Neutron creates a Subnet with the specified IP address range and other parameters. Neutron also associates the Subnet with the specified Network.