[ovs-discuss] MAC learning table does not always update

[Cheng Jin]

Thank, Ben. Can you please elaborate more about the optimization "should
only affect cases where a MAC
would otherwise quickly bounce back and forth between a number of learned
ports." I reproduced it with a simple setup which has only three switches
forming a triangle (VLAN set up to avoid loop), but the problem still
exists.

Is it possible for me to disable this optimization temporarily? If so, will
the bouncing issue be solved?

Thanks!
Cheng


On Tue, Mar 3, 2015 at 3:03 PM, Ben Pfaff <blp at nicira.com> wrote:

> On Tue, Mar 03, 2015 at 12:25:20PM -0600, Cheng Jin wrote:
> > I have a problem with updating OVS' MAC learning table, when it is in the
> > 'standalone' mode running like a legacy Ethernet bridge.
> >
> > The switch has an entry to a destination, including the destination MAC
> > (say, 00:00:00:00:00:01), an output port (say, 1), VLAN, and Age.
> However,
> > the switch sometimes does not update the entry, when it receives a packet
> > from the same destination (still 00:00:00:00:00:01) but from a new
> incoming
> > port (say, 2). Does someone know what may cause this issue?
> >
> > The MAC learning table is supposed to be updated once receiving a packet.
> > Does OVS do some optimization to process the packets so that the learning
> > table may not get updated when the packet rate is high?
>
> The optimization that OVS does should only affect cases where a MAC
> would otherwise quickly bounce back and forth between a number of
> learned ports.
>
> Is there anything unusual in your setup?  Can you reproduce this with
> a simple setup?
>



-- 
Cheng Jin

Ph.D Candidate
Department of Computer Science and Engineering
University of Minnesota
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://openvswitch.org/pipermail/ovs-discuss/attachments/20150303/79794d80/attachment-0002.html>