Hi Ben, If I just outputted these packets to the port that that OVS box is running on would that work? Or would the DL_DST address of the packet need to match that of the OVS box?
Thanks, Aaron On Sun, Jun 26, 2011 at 3:21 PM, Ben Pfaff <b...@nicira.com> wrote: > Yes, the PC running OVS would have to be used as a switch. If one of > your requirements is that you need more than the number of Ethernet > ports you can conveniently put in a PC chassis (which is often 6 to 10 > ports), then it's not a good way to go. > > Presumably the hardware switch's performance drops because the ASIC > can't do what you are asking and every packet has to be sent to the > switch CPU. Switch CPUs are usually quite slow and often the channel > from ASIC to CPU is ratelimited too. With OVS, every packet already > goes up to the CPU (that's a NIC's job after all) and there's very > little incremental cost to modifying a few headers. > > On Sun, Jun 26, 2011 at 03:15:48PM -0400, Aaron Rosen wrote: >> But in order to use OVS in this manor I would need a box running OVS >> that everyone first sent their traffic to first right? Is the reason >> why OVS can perform a factor of 1000 faster is because the >> implementation is better or because the hardware of a commodity PC is >> better for this than that of the OF switch that is doing the >> modifying? Just curious. >> >> On Sun, Jun 26, 2011 at 3:00 PM, Ben Pfaff <b...@nicira.com> wrote: >> > On Sun, Jun 26, 2011 at 02:54:13PM -0400, Aaron Rosen wrote: >> >> Thanks for your reply. I just tested this on the same HP just >> >> rewriting the DL_DST and the performance is the same there too so it >> >> must be done in software completely on these switches :( >> > >> > You mentioned a "high" rate of 683 Mbit/sec. If that's a good rate for >> > you, you don't need switching ASIC for that. Open vSwitch can handle >> > several gigabits per second on commodity PC server hardware. And its >> > performance won't drop by a factor of 1000 when you start modifying >> > headers. > -- Aaron O. Rosen Masters Student - Network Communication 306B Fluor Daniel _______________________________________________ openflow-discuss mailing list openflow-discuss@lists.stanford.edu https://mailman.stanford.edu/mailman/listinfo/openflow-discuss
