[ovs-discuss] ErrorMsg after requesting flow stats using OpenFlow 15

Ben Pfaff blp at ovn.org
Mon Nov 12 15:44:10 UTC 2018


OF1.5 has two different flow stats messages, OFPMP_FLOW_DESC and
OFPMP_FLOW_STATS.  OVS currently implements only the former.

On Mon, Nov 12, 2018 at 11:05:06AM +0100, Jozef Valko wrote:
> Ok, thanks.
> In the earlier message you mentioned that you don't see any problems with
> OF1.5 flow stats.
> So is there some other way how to get flow stats from the forwarders using
> OF1.5?
> 
> Thank you and regards.
> 
> 
> po 12. 11. 2018 o 0:47 Ben Pfaff <blp at ovn.org> napísal(a):
> 
> > OK, I took a look.  OVS just doesn't support that request in OF1.5 yet.
> > No one has implemented it.  As I've said, OF1.5 support is incomplete.
> >
> > On Sun, Nov 11, 2018 at 11:34:11PM +0100, Jozef Valko wrote:
> > > Thanks a lot!
> > > OVS version 2.9.0 was installed along with Mininet emulator. I've already
> > > tried to update OVS to v2.10.1, but Mininet then met some issues in
> > > creating the emulation. Anyway, there was the same error with the newest
> > > OVS version.
> > > I have created a PCAP file for you. Kindly please have a look at the
> > > packets no. 89 and 90, these are the request and error reply packets.
> > >
> > > Thank you for your time.
> > > Regards,
> > >  Jozef Valko.
> > >
> > >
> > > ne 11. 11. 2018 o 21:35 Ben Pfaff <blp at ovn.org> napísal(a):
> > >
> > > > On Sun, Nov 11, 2018 at 09:12:03PM +0100, Jozef Valko wrote:
> > > > > Hello all,
> > > > > I am developing an SDN application using Ryu and Mininet. My goal is
> > to
> > > > > develop security module on the top of Ryu controller. Therefore, I
> > need a
> > > > > regular statistics update from the forwarders which are OVS bridges.
> > For
> > > > > this purpose I am using OFPFlowStatsRequest function provided by Ryu
> > > > > parser. Below is the function which I am using:
> > > > > [image: image.png]
> > > > > This function runs in separate thread and sends the request every 10
> > > > > seconds.
> > > > > When I use this function with OpenFlow14 everything is fine, the
> > > > controller
> > > > > receives flow stats from the forwarder. But when I try to trigger
> > this
> > > > > function using OpenFlow15, the following error shows in the
> > controller
> > > > > window:
> > > > > [image: image.png]
> > > > > I tried to google this issue, searched in the specification and
> > Ryubook
> > > > but
> > > > > I did not find any solution. Because Ryu doesn't crash, I suppose
> > that
> > > > this
> > > > > is OVS-related issue.
> > > > > The only difference between requests in OF14 and OF15 is the value
> > of the
> > > > > field 'type'. In case of OF14 it is 1 and in case of OF15 it is 17.
> > Here
> > > > is
> > > > > the request before sending (OF15):
> > > > > [image: image.png]
> > > > > What can be an issue? How to properly request flow statistics from
> > the
> > > > OVS
> > > > > forwarders using Ryu and OpenFlow15?
> > > > > Versions of the applications:
> > > > > Mininet - 2.3.0d4
> > > > > Ryu - ryu-manager 4.29
> > > > > OVS - ovs_version: "2.9.0"
> > > > >
> > > > > PortStatsRequest function is working nicely in both OF14 and OF15.
> > > >
> > > > OVS doesn't fully support OpenFlow 1.5 and does not enable it by
> > > > default, so I suppose that you turned it on yourself.  That is fine--we
> > > > are pleased to hear about problems with protocol versions that are not
> > > > yet complete.  Also, I don't see any problems with OF1.5 flow stats and
> > > > it seems to work OK in my own simple test case with ovs-ofctl.
> > > >
> > > > However, for testing incomplete protocol versions, one should use the
> > > > latest version of Open vSwitch.  Please try the latest release v2.10.1
> > > > or what one can find on master.
> > > >
> > > > Alternatively, if you can provide a hex dump of the message that Ryu is
> > > > sending OVS (or otherwise some kind of exact representation), I can
> > test
> > > > that for you.
> > > >
> >
> >
> >


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