[pox-dev] POX on planetlab

Thu May 2 01:18:37 PDT 2013

The problem in my case is that even 1-2 minutes after having stopped the
POX controller, I still have pings. Despite the fact that there are no
flows in the flow table, I still have pings.
In order to stop having pings I need to delete the bridge from the switch
and recreate it again.

2013/5/1 Sayed Qaiser Ali Shah Shah <11msitqshah at seecs.edu.pk>

> Well i am not sure what is the problem but I tried it as below and it
> worked fine for me
> start controller:
>
> cd pox
> sudo ./pox.py forwarding.l2_learning
>
> it started controller. After that I created topology in another terminal
> using command
> sudo mn --topo single,4 --mac --controller remote
>
> This command created topology with one switch and 4 hosts.
> Then by command  "xterm s1" I open switch s1 in xterm. I checked entries
> via command
> ovs-ofctl dump-flows s1
> There were no flows in switch.
> Then I ping host h2 from h1 in terminal of Mininet
> h1 ping -c10 h2
> The ping was successful and when I checked switch there were flow entries.
> When I shutdown controller and ping hosts, switch still was having flow
> entries for about 10 to 15 seconds. The ping worked for that time  but
> after that time ping stopped because flow entries were deleted
> automatically.
> If you want to confirm that you need to check flow entries within 10-15
> seconds when you stop controller, you will get flow entries but after about
> 15 seconds ping will stop and there will be no flow entries in switch.
>
>
> On Tue, Apr 30, 2013 at 1:44 PM, Kouvakas Alexandros <questalex at gmail.com>wrote:
>
>> The weird thing is that:
>> Before starting POX, I delete the flows from the switch with ovs-ofctl
>> del-flows.
>> After that, I cannot have pings.
>> I start POX with l2_learning, and everything it's ok, I have pings.
>> The flows are deleted after the timeout.
>> I close POX.
>> I can still have pings until I shutdown the ovs servers etc. When I type
>> ovs-ofctl dump-flows, there are no flows on the switch but I can have
>> pings.. I cannot understand  why that happens.
>>
>>
>> 2013/4/29 Sayed Qaiser Ali Shah Shah <11msitqshah at seecs.edu.pk>
>>
>>>
>>> You can check flow in OVS by the following command in xterm of OVS
>>> ovs-ofctl dump-flows.
>>> It will show you all the flows in switch which were added.
>>>
>>>
>>>> Date: Mon, 29 Apr 2013 01:07:46 -0700
>>>> From: Murphy McCauley <murphy.mccauley at gmail.com>
>>>> To: Kouvakas Alexandros <questalex at gmail.com>
>>>> Cc: pox-dev at lists.noxrepo.org
>>>>
>>>> Subject: Re: [pox-dev] POX on planetlab
>>>> Message-ID: <C3DDA222-C02A-4009-8BFA-E9624EA35133 at gmail.com>
>>>> Content-Type: text/plain; charset="iso-8859-1"
>>>>
>>>>
>>>> (Inline)
>>>>
>>>> On Apr 29, 2013, at 12:56 AM, Kouvakas Alexandros wrote:
>>>>
>>>> > Sorry for asking again.Does anybody knows the answer on the above
>>>> question?
>>>>
>>>> Sorry; I've been busy.  Hopefully this brief reply will be helpful.
>>>>
>>>> > 2013/4/23 Kouvakas Alexandros <questalex at gmail.com>
>>>> > Hello,
>>>> > I managed to create my network as I would like it to be.
>>>> > So, I have one OVS and two hosts connected to it through tunnels.
>>>> > Before running the POX controller I delete the flows of the OVS with
>>>> "ovs-ofctl del-flows".So, after that I cannot have pings between the
>>>> machines.
>>>>
>>>> As a note, POX clears the tables as soon as switches connect by default.
>>>>
>>>> > After that I run the pox controller with the module of l2_learning,
>>>> so I have new flows and I have pings.
>>>> > How can I check the flows that are now added  in the flow table?
>>>>
>>>> If you want to do it from within POX, send a flow stats request.
>>>>  There's some info on the POX manual wiki:
>>>>
>>>> https://openflow.stanford.edu/display/ONL/POX+Wiki#POXWiki-Example-WebFlowStatistics
>>>>
>>>> That example filters them to only show ones on port 80, but obviously
>>>> you don't have to do that.  There's also a further example in the third
>>>> party section.  And POXDesk does this and displays them.
>>>>
>>>> If you want to do it from the commandline, look into ovs-ofctl.
>>>> (Something like ovs-ofctl show <switch-name>.)
>>>>
>>>> > I stop the POX controller and I still have pings,which means that the
>>>> flows are somewhere saved. I need to check this flows and furthermore to
>>>> modify them.
>>>>
>>>> Sure.  By default, nothing in POX uninstalls them when it shuts down
>>>> (though you could make this happen).  If I recall correctly, all the ones
>>>> from l2_learning have timeouts, so they'll expire eventually, but they'll
>>>> stick around until then.
>>>>
>>>> As mentioned above, look into ovs-ofctl.  And also ovs-dpctl.  Or write
>>>> a POX component to modify them how you want!
>>>>
>>>> -- Murphy
>>>>
>>>> > 2013/4/16 Kouvakas Alexandros <questalex at gmail.com>
>>>> > Hi,
>>>> > it's a bit irrelevant with pox mailing list but do you know how can I
>>>> create an overlay network with one node running OVS and some hosts that are
>>>> connected to the OVS through a subnet (let's say 192.168.3.1/24)
>>>> without running OVS on them. I mean, can I substitute the tunnel from the
>>>> host to the OVS with something else?
>>>> >
>>>> >
>>>> > 2013/4/12 Murphy McCauley <murphy.mccauley at gmail.com>
>>>> > On Apr 12, 2013, at 2:30 AM, Kouvakas Alexandros wrote:
>>>> >
>>>> >> Note that only the SENDER (the OF switch) has the controller. By
>>>> this I mean that I run "ovs-vsctl set-controller" only on the SENDER node.
>>>> >
>>>> > So each machine is running OVS, but only one of the OVS instances is
>>>> connecting to a controller?  In this case, you may be able to get them to
>>>> act as learning switches, but you can't program them from the controller,
>>>> which is going to prevent you from doing interesting path selection using
>>>> OpenFlow.  If that's what you want to do, connect them to the controller
>>>> either via the controller's external IP (131.188.44.100), or by setting up
>>>> in-band control and having the control traffic go through your tunnels.
>>>> >
>>>> > -- Murphy
>>>> >
>>>> >
>>>> >
>>>> > --
>>>> > Kouvakas Alexandros
>>>> >
>>>> >
>>>> >
>>>> > --
>>>> > Kouvakas Alexandros
>>>> >
>>>> >
>>>> >
>>>> > --
>>>> > Kouvakas Alexandros
>>>>
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>>>> End of pox-dev Digest, Vol 13, Issue 46
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>>>>
>>>
>>>
>>>
>>> --
>>> *Regards
>>>
>>> Sayed Qaiser Ali Shah
>>> MSIT-12
>>> NUST (SEECS)*
>>>
>>
>>
>>
>> --
>> Kouvakas Alexandros
>>
>
>
>
> --
> *Regards
>
> Sayed Qaiser Ali Shah
> MSIT-12
> NUST (SEECS)*
>

-- 
Kouvakas Alexandros
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