Introduction
In this blog post, you’ll learn how to create networks and set up a floating IP. By default, instances aren’t accessible from outside, as they’re located on internal networks. This is sufficient for instances without public access. However, if you require public access to your instance, a floating IP is absolutely essential.
Requirements
You will need access to the Cloud&Heat Horizon dashboard and an active project.
Setting up an internal network
Create a new network via the menu option Network > Networks and click on the button Create a network.
Set the subnet there demo subnet . The Network address or --subnet-range describes the entire private address range in CIDR notation. In the example, this comprises 10.1.0.0/24 the addresses of 10.1.0.0 to 10.1.0.255. The gateway IP 10.1.0.1 will later be assigned to the router’s internal interface.
Under Subnet details enables DHCP. The Provisioning pool or --allocation-pool specifies which addresses OpenStack is permitted to assign automatically to ports. It must be within the subnet. In the example, the addresses 10.1.0.100 to 10.1.0.200 used. Gateway and reserved addresses should not be included in this pool. You should also enter a DNS name server.
Or, alternatively, using the OpenStack CLI:
openstack network create demo-network
openstack subnet create demo-subnet \
--network demo-network \
--subnet-range 10.1.0.0/24 \
--gateway 10.1.0.1 \
--allocation-pool start=10.1.0.100,end=10.1.0.200 \
--dns-nameserver 9.9.9.9
Create a router
A router forwards data packets between your networks and is responsible for routing between them. In the example given in the blog post, we have the networks demo subnet as well as the public network interface public, which are to be linked together.
In the next step, set up a router that connects the internal network to a floating IP. You can set up a floating IP beforehand via the menu option Network > Floating IPs generate.
Next, open the router you have created and go to the tab Interfaces. Click on Add interface and select demo subnet from. Horizon uses the configured gateway IP for this 10.1.0.1.
Using the OpenStack CLI:
openstack router create demo-router
OpenStack router set --external-gateway public demo-router
openstack router add subnet demo-router demo-subnet
Final state of the network
You can view the current status of your network topology under the menu item Network > Network topology .
For the example configuration, this should look as follows:
The illustration shows the public network on the left public, on the right the internal demo-network with the address range 10.1.0.0/24 and in between the demo router. An instance and its floating IP are not yet accessible at this stage. They will be created in Chapter 6.
You can find further tutorials on working with OpenStack cloud environments here.
Contact
Are you not yet using our OpenStack cloud and interested in our IaaS? Please feel free to get in touch.
Max Böttcher
