[ovs-dev] Question about metadata matching

Ben Pfaff blp at nicira.com
Tue Aug 26 19:50:33 UTC 2014


Metadata is always 0 at the point that a packet enters the OpenFlow
pipeline, so there's no need for the datapath to match on it--it would
always be a match against 0.

On Tue, Aug 26, 2014 at 01:44:56PM -0600, Junguk Cho wrote:
> Oh, really?
> 
> Basically, what I understood is datapath keeps some tables based on "struct
> sw_flow_key" and  used  it for evaluating if incoming packet is matched or
> not.
> 
> Is it right or do I miss something?
> If I miss something, can you forward me to metadata matching in datapath?
> 
> Thanks,
> Junguk
> 
> 
> 2014-08-26 13:40 GMT-06:00 Ben Pfaff <blp at nicira.com>:
> 
> > On Tue, Aug 26, 2014 at 01:36:04PM -0600, Junguk Cho wrote:
> > > Hi, I have a simple question.
> > > When we use metadata as flow-rule,
> > > Does all traffic forward ofproto to match it because there is no match
> > > field in "struct sw_flow" in datapath?
> >
> > No, metadata matching still allows for kernel forwarding.  There's no
> > need to send every packet to userspace.
> >



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