[ovs-dev] [PATCH] ovn: Fix flows between 2 local ports.

Russell Bryant rbryant at redhat.com
Fri Aug 7 22:23:43 UTC 2015

On 08/07/2015 06:11 PM, Justin Pettit wrote:
> Thanks for tracking down the issue and supplying a patch, Russell.
> However, I think the core problem was that there was a missing flow.
> Specifically, the one described in the last sentence from this part
> of the ovn-architecture man page:
>                 Each  flow  in  table  32 matches on a logical output port for
>                 unicast or multicast logical ports that include a logical port
>                 on a remote hypervisor.  Each flow’s actions implement sending
>                 a packet to the port it matches.  For unicast  logical  output
>                 ports on remote hypervisors, the actions set the tunnel key to
>                 the correct value, then send the packet on the tunnel port  to
>                 the  correct hypervisor.  (When the remote hypervisor receives
>                 the packet, table 0 there will  recognize  it  as  a  tunneled
>                 packet  and pass it along to table 33.)  For multicast logical
>                 output ports, the actions send one copy of the packet to  each
>                 remote  hypervisor,  in  the  same way as for unicast destina‐
>                 tions.  If a multicast group includes a logical port or  ports
>                 on the local hypervisor, then its actions also resubmit to ta‐
>                 ble 33.  Table 32 also includes a fallback flow that resubmits
>                 to table 33 if there is no other match.
> I've sent out a patch, which I think addresses the issue.  Would you
> be able to review the patch and make sure it solves the problem you
> were seeing?
> I think we should work on some of the naming and descriptions of
> these flows, since it wasn't obvious to me that there should be a
> fallback flow for local traffic in the remote flow table!  I imagine
> this will improve over time.

Thanks a lot for digging into this and pointing out the missing flow!
That makes sense to me.  I'll give your patch a try now and let you know
how it goes.

Russell Bryant

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