[Users] internal networks in Ovirt

[Mike Kolesnik]

Lior gave a very detailed explanation, I added inline some comments on how
you can use the Neutron integration to achieve some of the things.

Regards,
Mike

----- Original Message -----
> Hello,
> 
> I'll start with your second question because it's simpler to answer: the
> only way to configure multiple networks on one physical host interface
> in oVirt is if all networks are VLAN-tagged, except for at most one
> network which would then have to be marked as non-VM (AKA bridgeless).
> In cases like yours ovirtmgmt is usually configured to be non-VM (you
> can edit it from the networks main tab, for example), and then add other
> bridged networks to be used within the VMs and VLAN-tag them.
> 
> As for your first question, I'll do my best to answer it, and hopefully
> others will correct me if I get anything wrong.
> 
> Bridged networks are the default in oVirt. When you create a new logical
> network within the oVirt webadmin console, mark it as a VM network and
> attach it to a host (and presumably later to a VM) - a bridge is created
> on the host with the logical network's name.
> 
> By internal networks, do you mean networks that are common to a host and
> to the VMs running on that host? If so, then this doesn't yet exist in
> oVirt, although the feature has been brought up and will probably be
> added sometime in the future (can't guarantee when though). I can think
> of a workaround, but it would require you to pin VMs to specific hosts,
> which is usually not something you'd wanna do when managing a virtual
> DC. Also, you might just connect to one VM from another on the same host
> (with a network that isn't defined as internal) and the traffic should
> be internal.

This can be achieved by using the Neutron integration, with the
Linux Bridge/OVS plugin set to "local" network type. This way every
external network you'll create will be host only.
I believe that starting from Havana you need to update the "default"
security group to allow all ingress traffic, in order for the VMs to be
able to communicate with each other.

> 
> If I'm not mistaken, NATing is not currently handled for you by oVirt;
> you would have to set it up manually on your network's default gateway
> or on your physical router.

This can also be achieved with the Neutron integration (but don't use
local networks) using routers that you configure directly on Neutron
(this integration is not supported from oVirt yet, but it should work).
For this to work, you need to make ovirtmgmt a non-VM network, as Lior
explained.

> 
> Other than that, if there's anything more specific you'd like to
> achieve, we'd be happy to help.
> 
> Yours, Lior.
> 
> On 06/10/13 16:45, subscription sites wrote:
> > Hi,
> > 
> > 
> > I just installed ovirt 3.3 and got everything up and running with an
> > ovirt node.
> > However, I can't figure out how the networking works in ovirt.
> > 
> > First of all, I'm looking for a feature like you have in virtualbox:
> > configure bridged networks, internal networks and natted networks, how
> > do you do each of these in ovirt?
> > 
> > Also, I have only one physical nic and ovirtmgmt default network is
> > already assigned to this nic.
> > How can I attach other bridged networks to this same physical nic?
> > 
> > 
> > Thanks for any help you can provide!
> > 
> > 
> >