[Openstack] Flat provider_network with vlan tagged interface or vlan provider_network with untagged interface

Antonio Messina antonio.s.messina at gmail.com
Wed Dec 3 12:47:15 UTC 2014

On Wed, Dec 3, 2014 at 3:32 AM, Abhijeet Rastogi
<abhijeet.1989 at gmail.com> wrote:
> Hi everyone,
> This is a very basic doubt and I'm trying to understand this
> fundamental thing about creating networks in neutron. My ultimate goal
> is to have all instances contain just one interface and a public IP on
> them. Now, this public IP can only exist in a specific VLAN, lets say,
> they'll only exist on eth0.123 (the is a vlan tagged interface on the
> host and I can directly bind public IPs to them and they work
> perfectly). I'm using linux bridge + ML2 as the plugin for neutron.

Hi Abhijeet,

I'm testing a similar deployment, since we will need it in our
next-to-come cloud infrastructure.

I've wrote my notes on what I have done so far at

The main issue I have found so far is that if you want to create a
single VLAN network and allow all tenants to attach VMs on that
network, you also have to modify the policy.json file on the
nova-compute. The problem with this solution is that it applies to
*any* external network, also the ones you would like to use for
floating IPs.


antonio.s.messina at gmail.com
antonio.messina at uzh.ch                     +41 (0)44 635 42 22
S3IT: Service and Support for Science IT   http://www.s3it.uzh.ch/
University of Zurich
Winterthurerstrasse 190
CH-8057 Zurich Switzerland

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