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How to setup network topology and floating IP pool with VirtualBox?

asked 2017-09-04 09:08:13 -0500

Jianliang gravatar image

Dear all,

I have installed 3 VMs nodes(controller, network and compute) on my desktop. My desktop is with Windows 7 Enterprise and Virtual Box 5.1.26. All VMs are CentOS7. Each VM has 3 network interfaces, host-only, NAT and bridged. Accordingly, the interfaces are enp0s3, enp0s8 and enp0s9. They are assigned IP addresses as (static), (static) and (static) respectively. I don't know how to create a network topology on the controller node. Which IP goes for private, which goes for router and its interface(s), and which goes for external/public? And how to create floating IP pool? Can any one give me some instructions please? Many thanks in advance.

Best regards,


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answered 2017-09-04 23:53:08 -0500

updated 2017-09-05 00:23:13 -0500

I believe you are confusing the networks that form the "datacenter" infrastructure (i.e., connecting your controllers, network and compute nodes) with Neutron networks.

The Networking guide provides a lot of information, assuming you either use Neutron's Linuxbridge or Openvswitch drivers.

In a nutshell, you need to use one of the three VirtualBox networks as the external network in your OpenStack cloud. This is automatically your floating IP pool. Ideally, this should be a network that allows you to get out to the internet from an OpenStack instance, and allows you to reach an instance from outside. Thus, don't use host-only for that.

Another network is for traffic between the VMs. Again, it depends on how you set it up. A popular set up is to use the VXLAN network type, which overlays a VXLAN network over the VM network. You can use host-only.

In a production environment, by the way, you would normally have a single physical network, or a bonded network, and use VLANs for all the various types of cloud network traffic - a VLAN for external traffic, a VLAN for connecting VMs, a VLAN for management including message queue, a VLAN for storage and so on.

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Thank you very much Bernd. Is it OK for the 3 VMs using same external network IP and using it as floating IP? as external IP is default setup by VirtualBox.

Jianliang gravatar imageJianliang ( 2017-09-05 05:05:59 -0500 )edit

Normally, all nodes use the same external network.

Bernd Bausch gravatar imageBernd Bausch ( 2017-09-05 13:37:29 -0500 )edit

answered 2017-09-05 05:14:03 -0500

Jianliang gravatar image

updated 2017-09-05 05:18:14 -0500

I am following ( to install OpenStack. The installation was stuck with STEP 7, passing the controlled and network nodes, but stuck with node compute forever.

I can interrupt the installation and log into OpenStack dashboard. But no floating IP pool available.

keyboard interrupt caused following message: * Time synchronization installation was skipped. Please note that unsynchronized time on server instances might be problem for some OpenStack components. * File /root/keystonerc_admin has been created on OpenStack client host To use the command line tools you need to source the file. * To access the OpenStack Dashboard browse to . Please, find your login credentials stored in the keystonerc_admin in your home directory. Traceback (most recent call last): File "/usr/bin/packstack", line 10, in <module> sys.exit(main()) File "/usr/lib/python2.7/site-packages/packstack/installer/", line 1022, in main _main(options, confFile, logFile) File "/usr/lib/python2.7/site-packages/packstack/installer/", line 678, in _main runSequences() File "/usr/lib/python2.7/site-packages/packstack/installer/", line 645, in runSequences controller.runAllSequences() File "/usr/lib/python2.7/site-packages/packstack/installer/", line 81, in runAllSequences, messages=self.MESSAGES) File "/usr/lib/python2.7/site-packages/packstack/installer/core/", line 109, in run, messages=messages) File "/usr/lib/python2.7/site-packages/packstack/installer/core/", line 50, in run self.function(config, messages) File "/usr/lib/python2.7/site-packages/packstack/plugins/", line 246, in apply_puppet_manifest wait_for_puppet(currently_running, messages) File "/usr/lib/python2.7/site-packages/packstack/plugins/", line 119, in wait_for_puppet time.sleep(3)

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If the controller nodes work, try to add a compute node.

However, your instructions use the RHEL version of Packstack. There is a Centos version:

Bernd Bausch gravatar imageBernd Bausch ( 2017-09-05 13:30:45 -0500 )edit

Thank you very much Bernd, I still followed the same tutorial, but rather than using the default VBox NAT, I created a NAT network with IPs range in the same as the host-only network. My floating IP can be allocated but can't be pingable or ssh-able.

Jianliang gravatar imageJianliang ( 2017-09-25 05:33:05 -0500 )edit

From where do you ping them?

My experience:

  • VBox with bridged NW
  • Pinging floating IPs from the controller VM works
  • Pinging them from outside doesn't

Something to do with the VBox bridge?

I replaced VBox with KVM virtualization - success! Of course you need a Linux PC to run KVM.

Bernd Bausch gravatar imageBernd Bausch ( 2017-09-26 22:18:13 -0500 )edit

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Asked: 2017-09-04 09:08:13 -0500

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Last updated: Sep 05 '17