> I see what you mean and I agree that a switch shouldn't store unnecessary > information. But is it really a burden in this case? The wildcards are stored > in a single 32-bit integer, so no extra space is needed. I also don't think > it should cause compatibility problems with controllers. If a controller sees > that the dl_type is 5, then it doesn't need to look at the unnecessary > wildcard fields.
Right, this is why I agree that it makes sense for OpenFlow switches to maintain the wildcards, since it is only 32 bits. My concern is that I can see the code in the OpenFlow reference implementation dates to a commit Ben made back in May 2008 (and the behavior may even predate that), and the Open vSwitch code has been this way from the beginning. Essentially, since there have been publicly available controllers, we've had this behavior. I'll check with some people who work more directly with the controller-side of things to see if they think this sort of change can be guaranteed not to affect any users' existing applications. At the same time, I'd encourage you to consider normalizing your flows before pushing them or using flow cookies, since that's most portable. --Justin _______________________________________________ discuss mailing list discuss@openvswitch.org http://openvswitch.org/mailman/listinfo/discuss_openvswitch.org
