On Apr 21, 2014, at 3:50 PM, Murphy McCauley <murphy.mccau...@gmail.com> wrote:
> A more straightforward approach is to actually have the controller machine
> exist on the data network. This is always the case when doing "in-band
> control". If your switches are, for example, Open vSwitch, the most
> straightforward way is using the "local" interface of the OVS instance. This
> interface is usually down by default, but you can up it. This connects the
> switch machine's local networking stack (which can obviously reach the
> controller because this is how the switch reaches the controller!) to the
> data network. Obviously, you'll need to install appropriate table entries to
> allow communication between the controller machine (via the local port) and
> the host (via whatever port it's connected to).
or you can just add a second interface to your controller, placing it on the
data-plane. :-) this keeps the simplicity and isolation of out-of-band
networking, while giving our controller and hosts easy communication.
I usually do this by creating a "controller host" in Mininet where I run my
controller (in your case, it would be POX). however, I don't put that host in a
separate namespace, which means that its loopback interface is in the same
namespace as all the switches (and gets used as the "control-plane" in
mininet). the regular eth-pair device gets attached to the switch
("data-plane"). see, for example:
https://github.com/brownsys/pane-demo-vm/blob/master/demos/PaneDemo.py#L56
in the physical testbed, we just use two NIC cards.
Andrew
