Hi Greg, That is fine.
Thanks, Anoop On Fri, Nov 23, 2018 at 1:10 PM Greg Mirsky <[email protected]> wrote: > Hi Anoop, > thank you for the consise text. I think I've got the idea. Would the minor > tweak be acceptable? > > In most cases, a single BFD session is sufficient for the given VTEP to > monitor > the reachability of a remote VTEP, regardless of the number of VNIs in > common. > When the single BFD session is used to monitor reachability of the remote > VTEP, > an implementation SHOULD use a VNI of 0. > > Regards, > Greg > > On Fri, Nov 23, 2018 at 10:47 AM Anoop Ghanwani <[email protected]> > wrote: > >> Hi Greg, >> >> I would recommend the following change. >> >> OLD >> >> 7. Use of reserved VNI >> >> BFD session MAY be established for the reserved VNI 0. One way to >> aggregate BFD sessions between VTEP's is to establish a BFD session >> with VNI 0. A VTEP MAY also use VNI 0 to establish a BFD session >> with a service node. >> >> NEW >> >> 7. Use of reserved VNI >> >> In most cases, only a single BFD session is necessary for a given VTEP >> to monitor the reachability to a remote VTEP, regardless of the number of >> VNIs in common. When a single session is used to monitor reachability >> remote VTEP, an implementation SHOULD use a VNI of 0. >> >> Thanks, >> Anoop >> >> On Thu, Nov 22, 2018 at 12:28 PM Greg Mirsky <[email protected]> >> wrote: >> >>> Hi Anoop, >>> apologies if my explanation was not clear. Non-zero VNIs are recommended >>> to be used by a VTEP that received BFD control packet with zero Your >>> Discriminator value. BFD control packets with non-zero Your Discriminator >>> value will be demultiplexed using only that value. As for the special role >>> of VNI 0 the section 7 of the draft states the following: >>> BFD session MAY be established for the reserved VNI 0. One way to >>> aggregate BFD sessions between VTEP's is to establish a BFD session >>> with VNI 0. A VTEP MAY also use VNI 0 to establish a BFD session >>> with a service node. >>> Would you suggest changing the normative language in this text? >>> >>> Regards, >>> Greg >>> >>> PS. Happy Thanksgiving to All! >>> >>> On Wed, Nov 21, 2018 at 11:00 PM Anoop Ghanwani <[email protected]> >>> wrote: >>> >>>> Hi Greg, >>>> >>>> See below prefixed with [ag4]. >>>> >>>> Thanks, >>>> Anoop >>>> >>>> On Wed, Nov 21, 2018 at 4:36 PM Greg Mirsky <[email protected]> >>>> wrote: >>>> >>>>> Hi Anoop, >>>>> apologies for the miss. Is it the last outstanding? Let's bring it to >>>>> the front then. >>>>> >>>>> - What is the benefit of running BFD per VNI between a pair of VTEPs? >>>>>>>>> >>>>>>>> GIM2>> An alternative would be to run CFM between VMs, if there's >>>>>>>> the need to monitor liveliness of the particular VM. Again, this is >>>>>>>> optional. >>>>>>>> >>>>>>> >>>>>>> [ag2] I'm not sure how running per-VNI BFD between the VTEPs allows >>>>>>> one to monitor the liveliness of VMs. >>>>>>> >>>>>> >>>>> [ag3] I think you missed responding to this. I'm not sure of the >>>>> value of running BFD per VNI between VTEPs. What am I getting that is not >>>>> covered by running a single BFD session with VNI 0 between the VTEPs? >>>>> >>>>> GIM3>> I've misspoken. Non-zero VNI is recommended to be used to >>>>> demultiplex BFD sessions between the same VTEPs. In section 6.1: >>>>> The procedure for demultiplexing >>>>> packets with Your Discriminator equal to 0 is different from >>>>> [RFC5880]. For such packets, the BFD session MUST be identified >>>>> using the inner headers, i.e., the source IP and the destination IP >>>>> present in the IP header carried by the payload of the VXLAN >>>>> encapsulated packet. The VNI of the packet SHOULD be used to derive >>>>> interface-related information for demultiplexing the packet. >>>>> >>>>> Hope that clarifies the use of non-zero VNI in VXLAN encapsulation of >>>>> a BFD control packet. >>>>> >>>> >>>> [ag4] This tells me how the VNI is used for BFD packets being >>>> sent/received. What is the use case/benefit of doing that? I am creating >>>> a special interface with VNI 0 just for BFD. Why do I now need to run BFD >>>> on any/all of the other VNIs? As a developer, if I read this spec, should >>>> I be building this capability or not? Basically what I'm getting at is I >>>> think the draft should recommend using VNI 0. If there is a convincing use >>>> case for running BFD over other VNIs serviced by that VTEP, then that needs >>>> to be explained. But as I mentioned before, this leads to scaling issues. >>>> So given the scaling issues, it would be good if an implementation only >>>> needed to worry about sending BFD messages on VNI 0. >>>> >>>> >>>>> >>>>> Regards, >>>>> Greg >>>>> >>>>>>
