CLI Client: Networks

This page describes how to use the Openstack CLI client to manage networks.

List Networks

openstack network list

List all networks accessible by your project.

The following filters are available:

Create a Private Network

openstack network create <new-network-name>
openstack subnet create --use-default-subnet-pool --network <new-network-name> <new-subnet-name>

To create a working private network. First create a private network. Then create (at least) 1 subnet attached to the private network.

If you do not have special subnet configuration requirements, we recommend using the --use-default-subnet-pool option in your openstack subnet create command to get a pre-configured /25 subnet, capable of accommodating up to 126 instances (1 IP address is reserved for the router, 1 for broadcast address).

If you need specific subnet configurations, see all the available options by running the openstack subnet create -h command.

For enable inbound or outbound access (which should be almost all use cases), you need to connect the private network to the public Internet. Create a router to connect the private network to the public Internet (i.e. the public network).

Delete a Network

openstack subnet delete <subnet-name-or-id>
openstack network delete <network-name-or-id>

To delete a network, first delete the subnet and then the network. All the instances and routers connected to the subnet need to be deleted first before the subnet is deleted.

List Routers

openstack router list

List all routers in your project.

Create a Router

openstack router create --external-gateway public <new-router-name>

Create a router. To connect the router to the public Internet, make sure to specify the --external-gateway public option. Source NAT (SNAT) is enabled for the new router by default.

Next connect a subnet to the new router so the router can start routing traffic to the connected subnet.

Connect a Router to a Subnet

openstack router add subnet <router-name-or-ip> <subnet-name-or-ip>

Connect the specified router to the specified subnet. If the router's external gateway is defined, the connected subnet should now have outbound access to the public Internet.

Delete a Router

openstack router delete <router-name>

Delete the specified router.

List Floating IP Addresses

openstack floating ip list

List all the floating addresses currently allocated to your project.

Create a Floating IP Address

openstack floating ip create <network-name-or-id>

Create a floating IP address on the specified network. To create a floating IP address on the public Internet, use public for network name, i.e. openstack floating ip create public.

Delete a Floating IP Address

openstack floating ip delete <IP-or-id>

Delete a floating IP address from the project.

Note

Once a floating IP address is deleted from the project, you will not able to get it back. If a floating IP is deleted by mistake, contact CAC Help for assistance.

Assign a Floating IP Address to an Instance

openstack server add floating ip <instance-name-or-id> <IP-or-id>

Assign a floating IP address to an instance. This command has 2 prerequisites:

  1. The instance must be connected to a private network.
  2. A router must connect the instance's private network and the public network with SNAT enabled (default setting).

Remove a Floating IP Address from an Instance

openstack server remove floating ip <instance-name-or-id> <IP-address>

Unassign the specified floating IP address from the instance. IP addresses are limited resources. If you no longer need the floating IP, please delete the floating IP to make it available for others.