[ovs-discuss] OVS sends ARP request to the controller also broadcasts ARP request

[Ben Pfaff]

That's true, generally speaking, but ovs-ofctl might have a few missing
features.  If you find any omissions, please report them.

On Tue, Apr 10, 2018 at 10:39:32PM +0000, Michael Williams wrote:
> Can every command that OvS recognizes from a controller also be done via the Linux command line?
> 
> 
> 
> -----Original Message-----
> From: ovs-discuss-bounces at openvswitch.org <ovs-discuss-bounces at openvswitch.org> On Behalf Of Ben Pfaff
> Sent: Tuesday, April 10, 2018 18:28
> To: Sh j <segunhz at gmail.com>
> Cc: ovs-discuss at openvswitch.org
> Subject: Re: [ovs-discuss] OVS sends ARP request to the controller also broadcasts ARP request
> 
> I think there's some confusion here.  OVS doesn't originate ARP requests.  It only forwards ARP requests generated by some other software, such as the Linux kernel.  If you don't want OVS to pass ARP requests to the controller via packet_in, then you can either configure the software that generates them not to do so, or you can configure OVS (via the controller) to forward them without generating a packet_in.
> 
> On Tue, Apr 10, 2018 at 05:54:36PM -0400, Sh j wrote:
> > Thank you. I fixed the problem through the flow table installed by 
> > ONOS and I do not see ARP broadcasts anymore.
> > 
> > 
> > 
> > 
> > I have another question about packet_in messages to the controller. 
> > Before that, I will explain about my topology. I asked related 
> > questions before but I still have a problem.
> > 
> > 
> > Usually, in the topology, OVS connected to hosts and they help hosts 
> > to communicate with each other. I prefer not to have any host and all 
> > nodes in my network acts as forwarding elements (running OVS) 
> > (especially in case of wireless networks, it is easier to add mobility to nodes without hosts).
> > 
> > After having this topology (OVS1--OVS2---OVS3), with the following
> > configuration:
> > 
> > OVS1(eth0) ------- (eth0)OVS2
> > 
> > ovs-vsctl add-br brx
> > ovs-vsctl add-port brx ethx
> > ip addr flush dev ethx
> > ip addr add 10.0.0.x/16 dev brx
> > ip link set brx up
> > 
> > 
> > when 10.0.0.1 (br1) pings 10.0.0.2(br2), node1 sends a packet_in
> > message(ICMP) to the controller(ONOS).
> > 
> > But, when 10.0.0.1(br1) pings 10.0.0.3(br3), node1 sends a packet_in
> > message(ARP) to the controller.
> > While I do not except this ARP request to the controller. I am 
> > expecting ICMP message as a packet_in to the controller in the first 
> > place, after that based on the packet_out, node1 is supposed to send 
> > the ARP request for the next hop. I do not know why OVS sends this ARP requests.
> > 
> >  In this case, which part of the network needs to change? should I 
> > change the configuration of OVS and how?
> > 
> > Thank you in advance
> > 
> > 
> > 
> > 
> > On Tue, Apr 10, 2018 at 4:27 PM, Ben Pfaff <blp at ovn.org> wrote:
> > 
> > > On Mon, Apr 09, 2018 at 01:09:37PM -0400, Sh j wrote:
> > > > Hello,
> > > >
> > > > I have the following topology:
> > > >
> > > > host1 ----openvswitch1 ----openvswitch2----host2
> > > >
> > > > and both openvswitches are connected to the ONOS controller.
> > > >
> > > > The problem is that when host1 ping host2, openvswitch1 sends the 
> > > > ARP request as a packet_in to the controller, Also, it broadcasts 
> > > > the ARP request so that openvswitch2 receives this broadcast.
> > > >
> > > > Do you have any suggestion how to avoid this ARP broadcast?
> > >
> > > I would guess that ONOS can control this behavior through the flow 
> > > table.
> > >
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