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External network for new Mitaka install?

asked 2016-05-02 19:15:05 -0500

velvetpixel gravatar image

updated 2016-05-02 19:16:05 -0500

I have completed an install of OpenStack using the Guide For Ubuntu.

The guide did not cover network creation, just neutron service setup.

I am able to create a private network that instances get assigned an IP from and instances can ping each other over that.

I am not able to understand how to set up a public network and a virtual router to use that.

My physical external network is with a gateway of and em2 on both controller and compute1 are physically connected to this network per the guide with the interface configured but no IP assigned.

I have a range in that network set aside for dhcp use within this OpenStack build of through 130. I also have and available.

I have tried making a new network of with the gateway of I created the range of 120-130. I then created a router and assigned to it. When I try to assign a gateway to the router there are no external networks available.

What are my next steps to create a correctly configured external network in OpenStack?

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answered 2016-05-03 10:36:57 -0500

elliotp gravatar image

updated 2016-05-03 10:37:24 -0500

Did you follow the guides on (this page) under the 'Create virtual networks' header? It shows how to create the provider and self service network.

I've done this, and I'm in the same boat as you unfortunately - new install of Mitaka and have no external network access.

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Your link made me dig and I see where I went wrong. The initial network setup instructions make it sound like you need to pick option 1 OR option 2. I went the route of option 2 not realizing I also needed to do option 1 to get both public and private. Looks like I need to backtrack

velvetpixel gravatar imagevelvetpixel ( 2016-05-03 17:04:49 -0500 )edit

Glad you got it sorted! I've only done option 1 so far, as i wanted to keep it simple. Can you do me a favour and create an instance on the provider network only (no nat) and see if you can ping it? I still can't get any external access to instances on the provider network.

elliotp gravatar imageelliotp ( 2016-05-04 04:02:50 -0500 )edit

answered 2016-05-12 02:43:26 -0500

OMI gravatar image

hi guys , i am also new t openstack i am trying to deploy openstack on two nodes that is controller and compute bt i am confused, the provider network that is external we are not setting any ip to it so how does it works does it occupies ip through our physical network dhcp ?

thank ou replying for our answers .

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answered 2016-05-15 02:15:15 -0500

todotani gravatar image

updated 2016-05-15 02:16:06 -0500

To create external network, there are two scenarios as described in the installation manual.
I assume that Scenario-2 and flat network (Because scenario-1 is not flexible) and use Linux bridge.
First edit the /etc/neutron/plugins/ml2/ml2_conf.ini as described in manual, especially set:

flat_networks = provider

And also specify in /etc/neutron/plugins/ml2/linuxbridge_agent.ini:

physical_interface_mappings = provider:em2    # em2 = interface name facing to external network

After configure and start neutron and related service, execute the following command with admin privilege:

$ source admin-openrc
$ neutron net-create ext-net --router:external \
 --provider:physical_network provider --provider:network_type flat \

$ neutron subnet-create ext-net --name ext-subnet \
  --allocation-pool start=,end= \
  --disable-dhcp --gateway

Then move to demo project (it is also possible to stay in admin if you like).

$ source demo-openrc 
$ neutron net-create Private
$ neutron subnet-create Private \
   --name Private-subnet --gateway --dns-nameserver   #<= your DNS server address

$ neutron router-create ext-router
$ neutron router-gateway-set ext-router ext-net
$ neutron router-interface-add ext-router Private-subnet
$ neutron router-show ext-router   # <= you can see external ip address assigned to ext-router

ping to external ip address of ext-router to verify connectivity.

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br-ex to configure on Controller only. right

rajkumar2507 gravatar imagerajkumar2507 ( 2017-06-22 08:12:15 -0500 )edit

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Asked: 2016-05-02 19:15:05 -0500

Seen: 4,723 times

Last updated: May 15 '16