Hi, all
I wonder why the installed megaflow is the one bellow: > The installed megaflow i see is this: > Megaflow: recirc_id=0,ip,in_port=2,dl_dst=fa:16:3e:e2:16:63,nw_dst= > 0.0.0.0/2.0.0.0,nw_frag=no Can 'nw_dst=0.0.0.0/2.0.0.0' matches any flow of which the prefix is 'network address: xxxxxx0x.xxxxxxxx.xxxxxxxx.xxxxxxxx 'network mask: 00000010.00000000.00000000.00000000' ? If so, then why? Thanks. At 2015-09-09 04:02:44, "Jarno Rajahalme" <jrajaha...@nicira.com> wrote: > >> On Sep 8, 2015, at 9:38 AM, Ben Pfaff <b...@nicira.com> wrote: >> >> On Tue, Sep 08, 2015 at 09:41:51AM +0300, Gal Sagie wrote: >>> for example: priority 100 match 10.0.0.0/24 go to controller >>> priority 100 match 10.0.0.1 go to next table >> >> That's a bad idea: these flows overlap so they should have different >> priorities. > >More specifically, assuming you want longest prefix match, you should give >higher priorities to longer prefixes. One way to do that is to add the prefix >length to the priority, i.e., for 10.0.0.0/24 use priority 124 and for >10.0.0.1 use priority 132. > > Jarno > >> >>> I am sending a generated packet using ovs-appctl with destination IP that >>> doesnt match >>> any subnet or specific IP in table 2 : >>> >>> ovs-appctl ofproto/trace br-int >>> in_port=2,dl_src=00:00:00:00:00:01,dl_dst=fa:16:3e:e2:16:63,eth_type=0x800,nw_dst=8.8.8.8,nw_src=192.1.1.1 >>> -generate >>> >>> The installed megaflow i see is this: >>> Megaflow: recirc_id=0,ip,in_port=2,dl_dst=fa:16:3e:e2:16:63,nw_dst= >>> 0.0.0.0/2.0.0.0,nw_frag=no >>> >>> The question is how does the nw_dst is calculated in this megaflow ? >>> is it finding a mask that doesnt fit any IP or subnet in table 2 and >>> calculate it? (it seems >>> like a hard task, especially with combined IP's and subnets matchers). >> >> Yes, that's what it's doing, see "Prefix Tracking" in classifier.h as >> well as the more formal description in our NSDI 2015 paper at >> http://openvswitch.org/support/papers/nsdi2015.pdf. It's not all that >> expensive, don't worry about it. >> >>> If i add a learning flow to this table with nw_dst of 8.8.8.8 (for example >>> do learning for every miss in table 2) is it going to be more efficient >>> performance wise? (because the megaflow would then be able to have nw_dst >>> of 8.8.8.8) >> >> Adding a flow for every actual nw_dst is going to be much much more >> expensive unless there are very few actual nw_dst. >> _______________________________________________ >> dev mailing list >> dev@openvswitch.org >> http://openvswitch.org/mailman/listinfo/dev > >_______________________________________________ >dev mailing list >dev@openvswitch.org >http://openvswitch.org/mailman/listinfo/dev _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
