[ovs-discuss] Test OVS kernel module using only one machine

[Markus.Linnakangas at tieto.com]

Hi,

You could also try using virtual eth pairs, like this:

ip link add type veth

That will give you veth0 and veth1 which are tied together. Connect one of them to your OVS bridge. Then give the other veth an IP address, and pump traffic into that, OVS should receive it via its pair.

Best regards,
Markus


On Tue Dec 18 11:28:20 PST 2012, Ahmed Talha Khan auny87 at gmail.com wrote:
>
> Good. I will give it a try next morning and give the results here. Thanks
> for the guidelines though.  I am also curious how does the entire dev team
> does its testing, because you said you adopted this approach. Is this
> approach common to all or there are other methods. What about the method
> that I proposed in my initial email?


> On Tue, Dec 18, 2012 at 7:59 PM, Kyle Mestery (kmestery) <kmestery at cisco.com
> > wrote:
> > On Dec 18, 2012, at 8:40 AM, Ahmed Talha Khan <auny87 at gmail.com> wrote:
> > >
> > > Ok cool. So then if i do :
> > >
> > > tcpreplay -i port0 pcap
> > >
> > > this traffic will be accepted by ovs as "ingrees" traffic on port0 even
> > when tcpreplay is out-bound replay on an interface?
> > >
> > I think that should work yes. Give it a shot and let us know.
> >
> >
> > >
> > > On Tue, Dec 18, 2012 at 7:34 PM, Kyle Mestery (kmestery) <
> > kmestery at cisco.com> wrote:
> > > On Dec 18, 2012, at 8:30 AM, Ahmed Talha Khan <auny87 at gmail.com> wrote:
> > > >
> > > > How do i use them if they are not on the host? I mean these are not
> > eth0/eth1 type actual interfaces, so how will they be visible on the host
> > until i make some device myself? How do you propose that I add the port.
> > > >
> > >
> > > The easiest way is this:
> > >
> > > ovs-vsctl add-port br0 port0  --  set  Interface  port0 type=internal
> > >
> > > In that example, you will see a "port0" interface if you do "ifconfig
> > port0". Create another one (port1 maybe) and you can then run your tests on
> > those ports, once you do "ifconfig port0/port1 up".
> > >
> > > >
> > > > On Tue, Dec 18, 2012 at 7:22 PM, Kyle Mestery (kmestery) <
> > kmestery at cisco.com> wrote:
> > > > On Dec 18, 2012, at 8:19 AM, Ahmed Talha Khan <auny87 at gmail.com>
> > wrote:
> > > > >
> > > > > I am not aware of the internal port functionality. Can you kindly
> > > elaborate your answer a bit more. Also what do you mean by "add IP
> > configuration on your bridge port"? How will that help in sending traffic
> > in?
> > > > >
> > > > Internal ports are internal ports created in OVS on the bridge. You
> > can use them on the host itself for different purposes, one of which is you
> > can apply IP configuration onto them. For the VXLAN testing I did, I would
> > use this functionality, for example. If you test does not require IP, then
> > just configure the port up and send traffic into it. Add another internal
> > port to receive the traffic on.
> > > >
> > > > >
> > > > > On Tue, Dec 18, 2012 at 7:14 PM, Kyle Mestery (kmestery) <
> > kmestery at cisco.com> wrote:
> > > > > On Dec 18, 2012, at 7:58 AM, Ahmed Talha Khan <auny87 at gmail.com>
> > wrote:
> > > > > > Hey Ben,Jesse,Kyle,ALL,
> > > > > >
> > > > > > I made some changes in the kernel module and would like to test
> > them. Ideally I would want to test it on a single machine that i am on
> > without firing up other vms(eg kvm/qemu integration). I would like to know
> > what is the preferred method used by the community for this.
> > > > > >
> > > > > > I thought of using a combination of tcpreplay and TAP devices to
> > achieve this. I only want send traffic into ovs-port 1, receive it in the
> > kernel mod, and send it out to  ovs-port 2 after doing my processing.
> >  Since I was trying to use tcpreplay,which is an out-bound utility(sends
> > traffic out of the stack), I need to make some interface on which i replay
> > this traffic. I made a TAP interface for this, since that can be used to
> > inject packets into the network stack. The problem is that when i replay
> > the traffic on this TAP device it is not received inside OVS obviously
> > because the TAP device only sends up the traffic to kernel but ovs will not
> > receive it since it  is not coming form any OVS port.
> > > > > >
> > > > > > Then there is a way to make 2 TAP devices, bridge them, play
> > traffic on one of them and add the 2nd one to ovs. But that is not possible
> > since OVS and linux bridge module cannot co-exist.
> > > > > >
> > > > > > So the questions is how to input traffic into ports, in a
> > non-programmatic way, without external vms.
> > > > > >
> > > > > > Also, are there any tests in the /test directory to test the
> > datapath functionality independent of the userland ovs code?
> > > > > >
> > > > > I usually just use OVS internal ports for this. Either add IP
> > configuration on your bridge port itself, or just create another internal
> > port and use that for your tests.
> > > > >
> > > > > Thanks,
> > > > > Kyle
> > > > >
> > > > > >
> >
> >
> >
> >
>
>
> --
> Regards,
> -Ahmed Talha Khan