[pox-dev] Can pox connect or communicate with host?

[Murphy McCauley]

Whether POX can communicate with your hosts is mostly a function of your network setup.  In lots of cases, the network that POX communicates to switches on and the network that the switches control are entirely separate and never actually meet (often these are called the control network and the data network respectivelt).  In this case, having POX and a host communicate directly isn't possible.  Indirectly, though, there's at least one kind of hacky possibility.  Sam Russell did an example of it -- tunneling between the data network and a tap interface on the controller machine over the OpenFlow connection via packet-in and packet-out.  (You could also potentially use pcap via pxpcap instead of a tap.)  There are issues with this approach, but it may suit some need.  You can read his blog post about it here:
http://pieknywidok.blogspot.com/2012/09/tunneling-traffic-through-your-openflow.html

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).

Hope that helps.

-- Murphy

On Apr 20, 2014, at 8:19 PM, Chanthan Hel <hel.chanthan65 at gmail.com> wrote:

> Dear all,
> As usual, POX can connect and keep communication with of switch.
> In case I want to to connect pox to host by using python socket. Is it possible??
> Moreover, in between POX and host  there is one ovs, it still be possible to connect??
> Chanthan
> 
> 
> -- 
> Mr. Chanthan Hel
> Electrical engineering, Faculty of Engineering,
> Chulalongkorn University (CU)
> 
> *Phone: +66 81 456 84 27*
>