On Fri, Nov 01, 2013 at 03:23:10PM +0900, YAMAMOTO Takashi wrote: > > On Tue, Oct 15, 2013 at 05:12:22PM +0900, YAMAMOTO Takashi wrote: > >> Signed-off-by: YAMAMOTO Takashi <yamam...@valinux.co.jp> > >> --- > >> OPENFLOW-1.1+ | 7 +++++++ > >> 1 file changed, 7 insertions(+) > >> > >> diff --git a/OPENFLOW-1.1+ b/OPENFLOW-1.1+ > >> index 07b2660..4f30520 100644 > >> --- a/OPENFLOW-1.1+ > >> +++ b/OPENFLOW-1.1+ > >> @@ -121,6 +121,13 @@ didn't compare the specs carefully yet.) > >> [optional for OF1.3+] > >> > >> * More flexible table miss support. > >> + This requires the following. > >> + - Change the default table-miss action (in the absense of table-miss > >> + entry) from packet_in to drop for OF1.3+. Decide what to do if > >> + a switch is configured to support multiple OF versions. > > > > I'm wondering what is a good approach to take here. > > > > It is possible to configure Open vSwitch (ovs-vswtichd) to only accept Open > > Flow 1.3+ connections. In which case it should be possible to select the > > default behaviour described above. However it is also possible for Open > > vSwitch (ovs-vswtichd) to be configured to accept a connections for Open > > Flow versions prior to 1.3, and 1.3+. > > > > This is complicated by the fact that OpenFlow 1.3 conveniently deprecates > > all the TABLE_MOD bits that allow configuration of this behaviour. Though I > > assume deprecated doesn't mean not allowed. > > > > With the constraints describe above and making the bold assumption that I'm > > not missing any further constraints I propose the following: > > > > A: > > 1. If Open vSwtich is configured to only accept connections > > for Open Flow 1.3+ then default to drop. > > > > 2. Otherwise use the current default, packet_in. > > > > Is this a good idea? It may be to subtle to be useful in practice. > > it sounds difficult to handle for controller-side programmers. > > > > > B: > > Implement TABLE_MOD to allow it to be used to control the behaviour > > of each table's miss behaviour. > > > > We could even go so far as to encourage people to use it, > > even if they are using Open Flow 1.3+, to ensure that the > > behaviour is what they expect. > > this leaves the question what should be the default.
I meant to do both A and B. But yes, it does side-step the issue to some extent. > > C: > decide what to do (packet-in or drop) per ofconn basis, > depending on OF versions. > (ofconn_receives_async_msg can take care of this.) That is fine, so long as there is one connection. And in the case where there is no controller then I think the OpenFlow 1.0 behaviour degrades to drop anyway. But I think we need to consider the case of multiple controllers. In particular two, both ROLE_EQUAL, that use OpenFlow versions with different defaults in this regards. I believe this is supported as of OpenFlow 1.2. > optionally, if a switch is configured to accept OF 1.3+ only, > drop it in kernel as an optimization. I guess it depends how cleanly it could be implemented. _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
