[ovs-discuss] selective packet mirror

[Ben Pfaff]

Maybe you just misunderstand the syntax.  "output:tap0" is always going
to be an error because output ports have to be specified by number,
e.g. "output:3" if tap0 is port 3.

On Fri, Feb 03, 2017 at 10:26:03AM -0800, Joo Yong-Seok wrote:
> Thanks for your answer. Actually, when I ran "ovs-ofctl" command to insert
> the rule, it complained like "output to unknown port". That seems to be
> first issue. I was trying to redirect the packet to tap0 by specifying the
> output port.
> Secondly, no matter what the error is, I ran the traffic, and definitely
> tap0 didn't receive any packet. So, dump the rule and there is no
> "output:tap0" action in the flow.
> 
> I am using pretty old version of ovs - which is 2.3.90 - and it may cause
> the issue? or any issue on tap0?
> 
> Best regards,
> 
> - yongseok
> 
> On Thu, Feb 2, 2017 at 1:40 PM, Ben Pfaff <blp at ovn.org> wrote:
> 
> > On Thu, Feb 02, 2017 at 01:12:02PM -0800, Joo Yong-Seok wrote:
> > > Hi,
> > >
> > > I am wondering is it possible to do "selective" packet mirroring. From
> > > previous question, I learnt how to enable port mirror on OVS port but I
> > > think that I should do "selective" packet mirroring since performance
> > issue.
> > >
> > > So, basically, I want to enable some sort of "filter" and want to mirror
> > > only specific filter. (like ARP, DHCP...)
> > >
> > > Basically, I created tap interface by using linux TUN module and want to
> > > send those packet to tap and make user-space application to listen it.
> > >
> > > Tried "actions" with multiple destination but, what I really want is kind
> > > of "mirror" type of thing - send an original packet to regular L2
> > > forwarding module and send a copied packet to "TAP" interface. (Tried
> > > actions=normal,output:tap0 but doesn't work).
> >
> > That solution is reasonable and I would expect it to work.  What actual
> > behavior did you see?
> >