Re: [pox-dev] Can pox connect or communicate with host?
Thx On Monday, April 21, 2014, Shiyao Ma i...@introo.me wrote: I am also in need of that functionality (and that need just came up in mind last night.) Here is my tentative thought: To emulate a real network environment, host shouldn't directly connect to the controller. The only way is through the edge switch (in a DCN environment). If we are using python socket, I think TCP is not a good choice, since whenever a related packet-in from the switch, the controller should maintain some state for the hand-shaking of the connection. Thus, we shall resort to UDP, though it loses some reliability (but as a recuse, reliability could be done in L5). 2014-04-21 11:19 GMT+08:00 Chanthan Hel hel.chantha...@gmail.comjavascript:_e(%7B%7D,'cvml','hel.chantha...@gmail.com'); : 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* -- 吾輩は猫である。ホームーページはhttp://introo.me。 -- Mr. Chanthan Hel Electrical engineering, Faculty of Engineering, Chulalongkorn University (CU) *Phone: +66 81 456 84 27*
Re: [pox-dev] Can pox connect or communicate with host?
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
Re: [pox-dev] Can pox connect or communicate with host?
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.chantha...@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*
