To create a subnet from the subnet pool MySubnetPool, use the openstack subnet create command with the --subnet-pool argument. To demonstrate this command in action, create a subnet with the following characteristics:
- Name: MySubnetFromPool
- Network: MyVLANNetwork2
- Prefix Length: 28
To create the subnet, refer to the following screenshot:
As shown in the preceding screenshot, the subnet's CIDR was carved from the provided subnet pool, and all other attributes were automatically determined by Neutron.
At the time of writing this book, the following bug may restrict the use of the OpenStack client when providing a prefix length when creating subnets: https://bugs.launchpad.net/python-openstacksdk/+bug/1754062. If an error occurs, try the Neutron client instead.