[Openstack] nova-network vs neutron

Jeremy Utley jerutley at gmail.com
Fri May 30 20:21:09 UTC 2014

Hello list,

I'm working on a proof-of-concept openstack installation for my company,
and am looking for the answers to some questions that I haven't been able
to find the answer to.  Hopefully someone here can help point me in the
right direction!

I've got a basic setup already in place - 2 controller nodes, 3 compute
nodes (with 5 more ready to provision when we line everything out).  The
main problems I'm facing right now is in the networking.  We need to
integrate this openstack setup with the network resources already in place
in our setup, and I'm not exactly sure how to do so.  I'll start off with
basically going over how we are currently setup.

1. Management and compute nodes are all connected via infiniband
networking, we are using this as our cluster management network
(10.30.x.x/16).  This network has zero connectivity to anything else - it's
completely private for the cluster.

2. eth2 on all compute nodes are connected to each other via a vlan on our
switch, and bridged to br100 to be our openstack fixed network.

3. eth1 on all compute nodes is connected up to our existing colo private
network.  We are currently defining this as our external network.  ( - In our current setup (with nova-network and the
FlatDHCPManager), I have taken a block of IP's from this subnet and
reserved them for use as floating IP's for testing purposes - this is
working perfectly right now.

4. eth0 on all compute nodes is connected to our existing colo public
network.  We have a /19 public allocation, broken up into numerous /24 and
/25 segments to keep independent divisions of the company fully segregated
- each segment is a separate vlan on the public network switches.  In what
we currently have setup, we are not utilizing this.

Ultimately, we'd like to have our cluster VM's connected to the fixed
network (on eth2), and treat both eth1 and eth0 as "public networks" we can
use floating IP's from.  All VM's should connect to eth1 and be able to
have floating IP's assigned from that network to them, and they should be
able to connect to a single tagged vlan on eth0 as well.

>From the reading I've done so far, I think what we are trying to do might
be too complicated for nova-network, since it depends on defining a single
interface as the public interface on the compute nodes, and we might
potentially have more.  Am I interpreting that correctly, or could we maybe
accomplish this with nova-network (perhaps using the VLANManager mode?)

If we have to switch to Neutron, can you run the neutron services on each
compute node?  We have concerns about scale if we have to implement a
separate network node, as we could easily end up saturating a full gig-e
interface with this cluster in the future.  Plus, the extra cost
expenditure of dedicated network nodes could end up cost-prohibitive in the
early stages of deployment.

Anyone got any suggestions for us?

Thank you for your time,

Jeremy Utley
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstack.org/pipermail/openstack/attachments/20140530/1dd4996e/attachment.html>

More information about the Openstack mailing list