[ovs-dev] OFPFMFC_OVERLAP Error

[Ben Pfaff]

On Wed, Dec 03, 2014 at 10:13:32AM -0800, Jarno Rajahalme wrote:
> 
> On Dec 2, 2014, at 11:34 AM, Ben Pfaff <blp at nicira.com> wrote:
> 
> > On Tue, Dec 02, 2014 at 11:30:26AM -0800, Ben Pfaff wrote:
> >> On Mon, Dec 01, 2014 at 10:50:45PM -0800, varanasi sandhya wrote:
> >>> OFPFF_CHECK_OVERLAP flag Issue:
> >>> 
> >>> When OFPFF_CHECK_OVERLAP flag is set at RYU controller in ofctl_v1_3.py
> >>> code in the mod_flow_entry definition, OVS should ideally return
> >>> OFPFMFC_OVERLAP error on inserting a duplicate flow with same priority and
> >>> match. But instead the new flow entry just replaces the old flow.
> >> 
> >> Do you have evidence to support this interpretation of the OpenFlow
> >> specification?
> > 
> > In fact, this is an unresolved question in the OpenFlow specification
> > working group.  Open issue EXT-406 addresses it.  I just added a
> > comment to try to revive the issue.
> 
> I bumped to this while working on the OF bundles code.. Would you mind
> summarizing which way EXT-406 proposes to address this? 

EXT-406 simply aims to resolve the question of whether a flow is
considered to overlap an existing identical flow, that is, whether a
flow_mod request for such a flow with OFPFF_CHECK_OVERLAP set should be
rejected.  The discussion in the ticket is about which direction it
should be resolved.  I don't feel like I have a dog in that fight, so
I'll let the people who do make the decision.