Re: [nvo3] BFD over VXLAN: Trapping BFD Control packet at VTEP

[Anoop Ghanwani <[e-mail]>]

Hi Joel,

Yes, existing implementations use VNI 0 for BFD over VXLAN.  Here are a
couple of references:
https://www.juniper.net/documentation/en_US/junos/topics/concept/sdn-ovsdb-bfd-nsx.html

https://www.cisco.com/c/en/us/products/collateral/switches/nexus-9000-series-switches/white-paper-c11-740091.html#_Toc18013665


I guess this document has been evolving and I have not kept up with it.
The version I had reviewed and commented on originally allowed for VNI 0.
The -04 version of the draft has this:
https://tools.ietf.org/html/draft-ietf-bfd-vxlan-04#section-7
What version are you referring to?

Thanks,
Anoop



On Mon, Oct 28, 2019 at 12:55 PM Joel M. Halpern <[e-mail]>
wrote:

> You are saying that there are existing implementations using VNI 0 for
> this?  Given that previous versions of the spec explicitly disallowed
> VNI 0, I am having trouble with your objecting that a spec for how to
> run over VNI 0 breask existing implementations.
>
> Note that when there is a good technical reason, the IETF does change
> Internet Drafts in ways that break early implementations.  That is the
> price of standardization.
>
> Yours,
> Joel
>
> On 10/28/2019 2:30 PM, Anoop Ghanwani wrote:
> > Hi Joel,
> >
> > Writing the spec in that way would make the current, inter-operable
> > implementation of multiple vendors non-compliant with the spec.
> >
> > Thanks,
> > Anoop
> >
> > On Mon, Oct 28, 2019 at 11:07 AM Joel M. Halpern <[e-mail]
> > <mailto:[e-mail]>> wrote:
> >
> >     I assumed this was only for the case where a tenant VNI was being
> used.
> >
> >     For the 0 VNI (which is what I prefer), always (MUST) use the
> loopback
> >     address.  There are no addresses assigned to the VTEP in that space.
> >     There is no IRB in that space.
> >
> >     Yours,
> >     Joel
> >
> >     On 10/28/2019 1:58 PM, Anoop Ghanwani wrote:
> >      > Joel,
> >      >
> >      > Are we going to qualify this by VNI?  There's a bunch of
> >     implementations
> >      > out there that don't use a tenant IP or a loopback with VNI
> 0--they
> >      > simply repeat the underlay IP in the inner IPDA.
> >      >
> >      > Thanks,
> >      > Anoop
> >      >
> >      > On Mon, Oct 28, 2019 at 10:46 AM Joel M. Halpern
> >     <[e-mail] <mailto:[e-mail]>
> >      > <mailto:[e-mail] <mailto:[e-mail]>>> wrote:
> >      >
> >      >     I can live with saying that you SHOULD use loopback, and MAY
> >     instead
> >      >     use
> >      >     an IP address in the customer space known to be owned by the
> VTEP
> >      >     device
> >      >     when such exists.
> >      >
> >      >     Yours,
> >      >     Joel
> >      >
> >      >     On 10/28/2019 1:32 PM, Anoop Ghanwani wrote:
> >      >      > Hi Joel,
> >      >      >
> >      >      > Perhaps we need to say use of an address owned by the
> device
> >      >     containing
> >      >      > the VTEP.
> >      >      >
> >      >      > Or are you suggesting that the use of the loopback address
> >     space
> >      >     is a MUST?
> >      >      >
> >      >      > Anoop
> >      >      >
> >      >      > On Mon, Oct 28, 2019 at 10:22 AM Joel M. Halpern
> >      >     <[e-mail] <mailto:[e-mail]>
> >     <mailto:[e-mail] <mailto:[e-mail]>>
> >      >      > <mailto:[e-mail] <mailto:[e-mail]>
> >     <mailto:[e-mail] <mailto:[e-mail]>>>> wrote:
> >      >      >
> >      >      >     There is something I am missing in your assumption
> >     about IRB.
> >      >      >
> >      >      >     As I understand VxLAN, the VTEP is under the control
> >     of the
> >      >     operator.
> >      >      >     As such, it is a pure bridge.  If you run IRB behind
> >     it, that
> >      >     is fine.
> >      >      >     Yes, an operator may offer IRB.  But as I understand
> it,
> >      >     conceptually,
> >      >      >     in terms of the VxLAN architecture the IRB is an entity
> >      >     behind the
> >      >      >     VTEP,
> >      >      >     not part of the VTEP.
> >      >      >
> >      >      >     Yours,
> >      >      >     Joel
> >      >      >
> >      >      >     On 10/28/2019 12:23 PM, Anoop Ghanwani wrote:
> >      >      >      > Santosh,
> >      >      >      >
> >      >      >      > Does it have to be a MUST?  What if I am running
> >     IRB and there
> >      >      >     are IP
> >      >      >      > addresses per VNI assigned to the VTEPs?  Why can
> the
> >      >     operator not
> >      >      >      > choose to use those?
> >      >      >      >
> >      >      >      > Anoop
> >      >      >      >
> >      >      >      > On Mon, Oct 28, 2019 at 7:51 AM Santosh P K
> >      >      >      > <[e-mail]
> >     <mailto:[e-mail]>
> >      >     <mailto:[e-mail]
> >     <mailto:[e-mail]>>
> >      >      >     <mailto:[e-mail]
> >     <mailto:[e-mail]>
> >      >     <mailto:[e-mail]
> >     <mailto:[e-mail]>>>
> >      >      >     <mailto:[e-mail]
> >     <mailto:[e-mail]>
> >      >     <mailto:[e-mail]
> >     <mailto:[e-mail]>>
> >      >      >     <mailto:[e-mail]
> >     <mailto:[e-mail]>
> >      >     <mailto:[e-mail]
> >     <mailto:[e-mail]>>>>> wrote:
> >      >      >      >
> >      >      >      >     Dinesh, Anoop et all,
> >      >      >      >           Lets us know if this text works for 127/8
> >      >     address range?
> >      >      >      >
> >      >      >      >     [proposed text for firewall]
> >      >      >      >
> >      >      >      >     "As per section 4 inner destination IP address
> >     MUST be
> >      >     set to
> >      >      >     127/8
> >      >      >      >     address. There may be firewall configured on
> >     VTEP to
> >      >     block 127/8
> >      >      >      >     address range if set as destination IP in inner
> IP
> >      >     header. It is
> >      >      >      >     recommended to allow 127/8 range address through
> >      >     firewall only if
> >      >      >      >     127/8 IP address is set as destination address
> >     in inner IP
> >      >      >     header."
> >      >      >      >
> >      >      >      >
> >      >      >      >     In section 4 we are talking about using 127/8
> >     and not
> >      >     really
> >      >      >     giving
> >      >      >      >     reason why. I think we should have text as RFC
> 5884
> >      >     has mentioned
> >      >      >      >     with below text.
> >      >      >      >
> >      >      >      >     [From RFC 5884]
> >      >      >      >     "The motivation for using the address range
> >     127/8 is
> >      >     the same as
> >      >      >      >     specified in Section 2.1 of [RFC4379]
> >      >      >      >     <
> https://tools.ietf.org/html/rfc4379#section-2.1>.
> >      >     This is an
> >      >      >      >     exception to the behavior defined in [RFC1122
> >      >      >      >     <https://tools.ietf.org/html/rfc1122>]."
> >      >      >      >
> >      >      >      >
> >      >      >      >
> >      >      >      >     Thanks
> >      >      >      >     Santosh P K
> >      >      >      >
> >      >      >      >
> >      >      >      >
> >      >      >      >     On Thu, Oct 24, 2019 at 1:24 AM Dinesh Dutt
> >      >     <[e-mail] <mailto:[e-mail]>
> >     <mailto:[e-mail] <mailto:[e-mail]>>
> >      >      >     <mailto:[e-mail] <mailto:[e-mail]>
> >     <mailto:[e-mail] <mailto:[e-mail]>>>
> >      >      >      >     <mailto:[e-mail]
> >     <mailto:[e-mail]> <mailto:[e-mail]
> >     <mailto:[e-mail]>>
> >      >     <mailto:[e-mail] <mailto:[e-mail]>
> >     <mailto:[e-mail] <mailto:[e-mail]>>>>> wrote:
> >      >      >      >
> >      >      >      >         Looks good to me Greg. I see that the text
> >     around
> >      >     the use
> >      >      >     of the
> >      >      >      >         inner IP address as also quite acceptable.
> Will
> >      >     you add any
> >      >      >      >         words about the firewall?
> >      >      >      >
> >      >      >      >         Dinesh
> >      >      >      >
> >      >      >      >         On Wed, Oct 23, 2019 at 8:36 PM, Greg Mirsky
> >      >      >      >         <[e-mail]
> >     <mailto:[e-mail]>
> >      >     <mailto:[e-mail] <mailto:[e-mail]>>
> >     <mailto:[e-mail] <mailto:[e-mail]>
> >      >     <mailto:[e-mail] <mailto:[e-mail]
> >>>
> >      >      >     <mailto:[e-mail]
> >     <mailto:[e-mail]> <mailto:[e-mail]
> >     <mailto:[e-mail]>>
> >      >     <mailto:[e-mail] <mailto:[e-mail]>
> >     <mailto:[e-mail] <mailto:[e-mail]>>>>>
> wrote:
> >      >      >      >>         Hi Dinesh, et al.,
> >      >      >      >>         please check the updated version that
> >     removed the
> >      >      >     reference to
> >      >      >      >>         Hypervisor in the text and Figure 1.
> >      >      >      >>
> >      >      >      >>         Regards,
> >      >      >      >>         Greg
> >      >      >      >>
> >      >      >      >>         On Wed, Oct 23, 2019 at 10:47 AM Santosh P
> K
> >      >      >      >>         <[e-mail]
> >     <mailto:[e-mail]>
> >      >     <mailto:[e-mail]
> >     <mailto:[e-mail]>>
> >      >      >     <mailto:[e-mail]
> >     <mailto:[e-mail]>
> >      >     <mailto:[e-mail]
> >     <mailto:[e-mail]>>>
> >      >      >      >>         <mailto:[e-mail]
> >     <mailto:[e-mail]>
> >      >     <mailto:[e-mail]
> >     <mailto:[e-mail]>>
> >      >      >     <mailto:[e-mail]
> >     <mailto:[e-mail]>
> >      >     <mailto:[e-mail]
> >     <mailto:[e-mail]>>>>> wrote:
> >      >      >      >>
> >      >      >      >>             Dinesh,
> >      >      >      >>                  Please see my inline comments
> [SPK]
> >      >      >      >>
> >      >      >      >>
> >      >      >      >>                 - In section 3, there's a sentence
> >     that
> >      >     is: "BFD
> >      >      >      >>                 packets intended for a Hypervisor
> >     VTEP MUST
> >      >      >     NOT..". I
> >      >      >      >>                 recommend getting rid of the word
> >      >     "Hypervisor" ashe
> >      >      >      >>                 logic applies to any VTEP.
> >      >      >      >>
> >      >      >      >>             [SPK] Thanks for comments. We will
> >     change this.
> >      >      >      >>
> >      >      >      >>                 - You already explained the
> >     precedence of
> >      >     the use of
> >      >      >      >>                 127/8 address in the inner header
> in
> >      >     MPLS. I have no
> >      >      >      >>                 specific comments in that area. I
> have
> >      >     only two
> >      >      >      >>                 questions:
> >      >      >      >>                    - Has anybody verified that the
> >     use of
> >      >     127/8
> >      >      >      >>                 address (and the right MAC) works
> with
> >      >     existing
> >      >      >      >>                 implementations, including the
> silicon
> >      >     ones? If this
> >      >      >      >>                 doesn't work there, is it worth
> >     adding the
> >      >      >     possibilit
> >      >      >      >>                 y of another address, one that is
> >     owned
> >      >     by the
> >      >      >     VTEP node?
> >      >      >      >>
> >      >      >      >>                    - Do we know if Firewalls stop
> >     such VXLAN
> >      >      >     packets?
> >      >      >      >>                 I ask this because VXLAN has an IP
> >     header
> >      >     and I
> >      >      >     don't
> >      >      >      >>                 know if firewalls stop packets
> >     with 127/8
> >      >     in the
> >      >      >     inner
> >      >      >      >>                 header. If not, is it worth adding
> a
> >      >     sentence to say
> >      >      >      >>                 that firewalls  allow such
> >     packets? The
> >      >     use of a
> >      >      >      >>                 non-127/8 address may alleviate
> >     this case
> >      >     as well.
> >      >      >      >>
> >      >      >      >>             [SPK] I think we may need to add the
> text
> >      >     about firewall
> >      >      >      >>             as some checks in firewall will be
> >     there if
> >      >     they are not
> >      >      >      >>             already using MPLS OAM which has inner
> IP
> >      >     header with
> >      >      >      >>             127/8 address range.
> >      >      >      >>
> >      >      >      >>
> >      >      >      >>                 The rest of the draft looks good
> >     to me,
> >      >      >      >>
> >      >      >      >>                 Dinesh
> >      >      >      >>
> >      >      >      >>                 On Wed, Oct 23, 2019 at 7:58 AM,
> >     Greg Mirsky
> >      >      >      >>                 <[e-mail]
> >     <mailto:[e-mail]>
> >      >     <mailto:[e-mail] <mailto:[e-mail]>>
> >      >      >     <mailto:[e-mail]
> >     <mailto:[e-mail]> <mailto:[e-mail]
> >     <mailto:[e-mail]>>>
> >      >     <mailto:[e-mail] <mailto:[e-mail]>
> >     <mailto:[e-mail] <mailto:[e-mail]>>
> >      >      >     <mailto:[e-mail]
> >     <mailto:[e-mail]> <mailto:[e-mail]
> >     <mailto:[e-mail]>>>>>
> >      >      >      >>                 wrote:
> >      >      >      >>>                 Hi Dinesh,
> >      >      >      >>>                 I greatly appreciate your
> comments.
> >      >     Please heave a
> >      >      >      >>>                 look at the attached copy of the
> >     working
> >      >      >     version and
> >      >      >      >>>                 its diff to -07 (latest in the
> >     datatracker).
> >      >      >      >>>
> >      >      >      >>>                 Regards,
> >      >      >      >>>                 Greg
> >      >      >      >>>
> >      >      >      >>>                 On Tue, Oct 22, 2019 at 9:52 PM
> >     Dinesh Dutt
> >      >      >      >>>                 <[e-mail]
> >     <mailto:[e-mail]>
> >      >     <mailto:[e-mail] <mailto:[e-mail]>>
> >     <mailto:[e-mail] <mailto:[e-mail]>
> >      >     <mailto:[e-mail] <mailto:[e-mail]>>>
> >      >      >     <mailto:[e-mail] <mailto:[e-mail]>
> >     <mailto:[e-mail] <mailto:[e-mail]>>
> >      >     <mailto:[e-mail] <mailto:[e-mail]>
> >     <mailto:[e-mail] <mailto:[e-mail]>>>>> wrote:
> >      >      >      >>>
> >      >      >      >>>                     I have the same feeling as
> Anoop.
> >      >     Greg, can you
> >      >      >      >>>                     please point me to the latest
> >     draft
> >      >     so that
> >      >      >     I can
> >      >      >      >>>                     quickly glance through it to
> be
> >      >     doubly sure,
> >      >      >      >>>
> >      >      >      >>>                     Dinesh
> >      >      >      >>>
> >      >      >      >>>                     On Wed, Oct 23, 2019 at 4:35
> AM,
> >      >     Anoop Ghanwani
> >      >      >      >>>                     <[e-mail]
> >     <mailto:[e-mail]>
> >      >     <mailto:[e-mail] <mailto:[e-mail]>>
> >      >      >     <mailto:[e-mail]
> >     <mailto:[e-mail]> <mailto:[e-mail]
> >     <mailto:[e-mail]>>>
> >      >      >      >>>                     <mailto:[e-mail]
> >     <mailto:[e-mail]>
> >      >     <mailto:[e-mail] <mailto:[e-mail]>>
> >      >      >     <mailto:[e-mail]
> >     <mailto:[e-mail]>
> >      >     <mailto:[e-mail]
> >     <mailto:[e-mail]>>>>> wrote:
> >      >      >      >>>>                     Greg,
> >      >      >      >>>>
> >      >      >      >>>>                     I think the draft is fine as
> is.
> >      >      >      >>>>
> >      >      >      >>>>                     I discussion with Xiao Min
> was
> >      >     about #3 and I
> >      >      >      >>>>                     see that as unnecessary
> until we
> >      >     have a draft
> >      >      >      >>>>                     that explains why that is
> >     needed in the
> >      >      >     context
> >      >      >      >>>>                     of the NVO3 architecture.
> >      >      >      >>>>
> >      >      >      >>>>                     Anoop
> >      >      >      >>>>
> >      >      >      >>>>                     On Tue, Oct 22, 2019 at
> 11:17 AM
> >      >     Greg Mirsky
> >      >      >      >>>>                     <[e-mail]
> >     <mailto:[e-mail]>
> >      >     <mailto:[e-mail] <mailto:[e-mail]>>
> >      >      >     <mailto:[e-mail]
> >     <mailto:[e-mail]> <mailto:[e-mail]
> >     <mailto:[e-mail]>>>
> >      >      >      >>>>
> >       <mailto:[e-mail] <mailto:[e-mail]>
> >      >     <mailto:[e-mail] <mailto:[e-mail]>>
> >      >      >     <mailto:[e-mail]
> >     <mailto:[e-mail]>
> >      >     <mailto:[e-mail]
> >     <mailto:[e-mail]>>>>> wrote:
> >      >      >      >>>>
> >      >      >      >>>>                         Hi Anoop, et al.,
> >      >      >      >>>>                         I agree with your
> >     understanding
> >      >     of what is
> >      >      >      >>>>                         being defined in the
> current
> >      >     version
> >      >      >     of the
> >      >      >      >>>>                         BFD over VxLAN
> >     specification.
> >      >     But, as I
> >      >      >      >>>>                         understand, the WG is
> >      >     discussing the scope
> >      >      >      >>>>                         before the WGLC is
> closed. I
> >      >     believe there
> >      >      >      >>>>                         are three options:
> >      >      >      >>>>
> >      >      >      >>>>                          1. single BFD session
> >     between
> >      >     two VTEPs
> >      >      >      >>>>                          2. single BFD session
> >     per VNI
> >      >     between
> >      >      >     two VTEPs
> >      >      >      >>>>                          3. multiple BFD
> >     sessions per
> >      >     VNI between
> >      >      >      >>>>                             two VTEPs
> >      >      >      >>>>
> >      >      >      >>>>                         The current text
> >     reflects #2. Is WG
> >      >      >     accepts
> >      >      >      >>>>                         this scope? If not, which
> >      >     option WG would
> >      >      >      >>>>                         accept?
> >      >      >      >>>>
> >      >      >      >>>>                         Regards,
> >      >      >      >>>>                         Greg
> >      >      >      >>>>
> >      >      >      >>>>                         On Tue, Oct 22, 2019 at
> >     2:09 PM
> >      >     Anoop
> >      >      >      >>>>                         Ghanwani
> >     <[e-mail] <mailto:[e-mail]>
> >      >     <mailto:[e-mail] <mailto:[e-mail]>>
> >      >      >     <mailto:[e-mail]
> >     <mailto:[e-mail]> <mailto:[e-mail]
> >     <mailto:[e-mail]>>>
> >      >      >      >>>>
> >       <mailto:[e-mail] <mailto:[e-mail]>
> >      >     <mailto:[e-mail] <mailto:[e-mail]>>
> >      >      >     <mailto:[e-mail]
> >     <mailto:[e-mail]>
> >      >     <mailto:[e-mail]
> >     <mailto:[e-mail]>>>>> wrote:
> >      >      >      >>>>
> >      >      >      >>>>                             I concur with Joel's
> >     assessment
> >      >      >     with the
> >      >      >      >>>>                             following
> >     clarifications.
> >      >      >      >>>>
> >      >      >      >>>>                             The current document
> >     is already
> >      >      >     capable
> >      >      >      >>>>                             of monitoring
> >     multiple VNIs
> >      >      >     between VTEPs.
> >      >      >      >>>>
> >      >      >      >>>>                             The issue under
> >     discussion
> >      >     was how
> >      >      >     do we
> >      >      >      >>>>                             use BFD to monitor
> >     multiple
> >      >     VAPs that
> >      >      >      >>>>                             use the same VNI
> >     between a
> >      >     pair of
> >      >      >      >>>>                             VTEPs.  The use case
> for
> >      >     this is not
> >      >      >      >>>>                             clear to me, as from
> my
> >      >     understanding,
> >      >      >      >>>>                             we cannot have a
> >     situation with
> >      >      >     multiple
> >      >      >      >>>>                             VAPs using the same
> >      >     VNI--there is 1:1
> >      >      >      >>>>                             mapping between VAP
> >     and VNI.
> >      >      >      >>>>
> >      >      >      >>>>                             Anoop
> >      >      >      >>>>
> >      >      >      >>>>                             On Tue, Oct 22, 2019
> >     at 6:06 AM
> >      >      >     Joel M.
> >      >      >      >>>>                             Halpern
> >      >     <[e-mail] <mailto:[e-mail]>
> >     <mailto:[e-mail] <mailto:[e-mail]>>
> >      >      >     <mailto:[e-mail]
> >     <mailto:[e-mail]> <mailto:[e-mail]
> >     <mailto:[e-mail]>>>
> >      >      >      >>>>
> >       <mailto:[e-mail] <mailto:[e-mail]>
> >      >     <mailto:[e-mail] <mailto:[e-mail]>>
> >      >      >     <mailto:[e-mail]
> >     <mailto:[e-mail]> <mailto:[e-mail]
> >     <mailto:[e-mail]>>>>>
> >      >     wrote:
> >      >      >      >>>>
> >      >      >      >>>>                                  From what I can
> >     tell,
> >      >     there
> >      >      >     are two
> >      >      >      >>>>                                 separate
> problems.
> >      >      >      >>>>                                 The document we
> >     have is a
> >      >      >     VTEP-VTEP
> >      >      >      >>>>                                 monitoring
> >     document.
> >      >     There is no
> >      >      >      >>>>                                 need for that
> >     document to
> >      >      >     handle the
> >      >      >      >>>>                                 multiple VNI
> case.
> >      >      >      >>>>                                 If folks want a
> >      >     protocol for doing
> >      >      >      >>>>                                 BFD monitoring
> >     of things
> >      >      >     behind the
> >      >      >      >>>>                                 VTEPs (multiple
> >     VNIs),
> >      >     then do
> >      >      >     that
> >      >      >      >>>>                                 as a separate
> >      >     document.   The
> >      >      >      >>>>                                 encoding will be
> >     a tenant
> >      >      >     encoding,
> >      >      >      >>>>                                 and thus
> >     sesparate from
> >      >     what is
> >      >      >      >>>>                                 defined in this
> >     document.
> >      >      >      >>>>
> >      >      >      >>>>                                 Yours,
> >      >      >      >>>>                                 Joel
> >      >      >      >>>>
> >      >      >      >>>>                                 On 10/21/2019
> >     5:07 PM,
> >      >     Jeffrey
> >      >      >     Haas
> >      >      >      >>>>                                 wrote:
> >      >      >      >>>>                                 > Santosh and
> >     others,
> >      >      >      >>>>                                 >
> >      >      >      >>>>                                 > On Thu, Oct
> >     03, 2019 at
> >      >      >     07:50:20PM
> >      >      >      >>>>                                 +0530, Santosh P
> >     K wrote:
> >      >      >      >>>>                                 >>     Thanks
> >     for your
> >      >      >     explanation.
> >      >      >      >>>>                                 This helps a
> lot. I
> >      >     would wait
> >      >      >     for more
> >      >      >      >>>>                                 >> comments from
> >     others
> >      >     to see if
> >      >      >      >>>>                                 this what we
> >     need in this
> >      >      >     draft to be
> >      >      >      >>>>                                 >> supported
> >     based on
> >      >     that we can
> >      >      >      >>>>                                 provide
> appropriate
> >      >     sections
> >      >      >     in the
> >      >      >      >>>>                                 draft.
> >      >      >      >>>>                                 >
> >      >      >      >>>>                                 > The threads on
> the
> >      >     list have
> >      >      >      >>>>                                 spidered to the
> >     point
> >      >     where it is
> >      >      >      >>>>                                 challenging
> >      >      >      >>>>                                 > to follow what
> the
> >      >     current
> >      >      >     status
> >      >      >      >>>>                                 of the draft is,
> >     or should
> >      >      >     be.  :-)
> >      >      >      >>>>                                 >
> >      >      >      >>>>                                 > However, if
> I've
> >      >     followed things
> >      >      >      >>>>                                 properly, the
> >     question
> >      >     below is
> >      >      >      >>>>                                 really the
> >      >      >      >>>>                                 > hinge point on
> >     what our
> >      >      >      >>>>                                 encapsulation
> >     for BFD
> >      >     over vxlan
> >      >      >      >>>>                                 should look like.
> >      >      >      >>>>                                 > Correct?
> >      >      >      >>>>                                 >
> >      >      >      >>>>                                 > Essentially,
> >     do we or
> >      >     do we not
> >      >      >      >>>>                                 require the
> >     ability to
> >      >     permit
> >      >      >      >>>>                                 multiple BFD
> >      >      >      >>>>                                 > sessions
> between
> >      >     distinct VAPs?
> >      >      >      >>>>                                 >
> >      >      >      >>>>                                 > If this is so,
> >     do we
> >      >     have a
> >      >      >     sense
> >      >      >      >>>>                                 as to how we
> should
> >      >     proceed?
> >      >      >      >>>>                                 >
> >      >      >      >>>>                                 > -- Jeff
> >      >      >      >>>>                                 >
> >      >      >      >>>>                                 > [context
> preserved
> >      >     below...]
> >      >      >      >>>>                                 >
> >      >      >      >>>>                                 >> Santosh P K
> >      >      >      >>>>                                 >>
> >      >      >      >>>>                                 >> On Wed, Sep
> >     25, 2019
> >      >     at 8:10 AM
> >      >      >      >>>>
> >       <[e-mail] <mailto:[e-mail]>
> >      >     <mailto:[e-mail] <mailto:[e-mail]>>
> >      >      >     <mailto:[e-mail]
> >     <mailto:[e-mail]> <mailto:[e-mail]
> >     <mailto:[e-mail]>>>
> >      >      >      >>>>
> >      >       <mailto:[e-mail] <mailto:[e-mail]>
> >     <mailto:[e-mail] <mailto:[e-mail]>>
> >      >      >     <mailto:[e-mail]
> >     <mailto:[e-mail]> <mailto:[e-mail]
> >     <mailto:[e-mail]>>>>>
> >      >     wrote:
> >      >      >      >>>>                                 >>
> >      >      >      >>>>                                 >>> Hi Santosh,
> >      >      >      >>>>                                 >>>
> >      >      >      >>>>                                 >>>
> >      >      >      >>>>                                 >>> With regard
> >     to the
> >      >     question
> >      >      >      >>>>                                 whether we
> >     should allow
> >      >      >     multiple BFD
> >      >      >      >>>>                                 sessions
> >      >      >      >>>>                                 >>> for the same
> >     VNI or
> >      >     not,
> >      >      >     IMHO we
> >      >      >      >>>>                                 should allow it,
> >     more
> >      >      >     explanation as
> >      >      >      >>>>                                 >>> follows.
> >      >      >      >>>>                                 >>>
> >      >      >      >>>>                                 >>> Below is a
> >     figure
> >      >     derived from
> >      >      >      >>>>                                 figure 2 of
> >     RFC8014 (An
> >      >      >     Architecture for
> >      >      >      >>>>                                 >>> Data-Center
> >     Network
> >      >      >      >>>>                                 Virtualization
> >     over Layer 3
> >      >      >     (NVO3)).
> >      >      >      >>>>                                 >>>
> >      >      >      >>>>                                 >>>
> >              |
> >      >      >      >>>>                                  Data Center
> Network
> >      >     (IP)        |
> >      >      >      >>>>                                 >>>
> >              |
> >      >      >      >>>>
> >      >             |
> >      >      >      >>>>                                 >>>
> >      >      >      >>>>
> >      >      >       +-----------------------------------------+
> >      >      >      >>>>                                 >>>
> >      >             |
> >      >      >      >>>>
> >           |
> >      >      >      >>>>                                 >>>
> >      >             |
> >      >      >      >>>>                                  Tunnel Overlay
> >          |
> >      >      >      >>>>                                 >>>
> >      >      >      >>>>
> >       +------------+---------+
> >      >      >      >>>>
> >        +---------+------------+
> >      >      >      >>>>                                 >>>
> |
> >      >      >      >>>>
> >       +----------+-------+ |
> >      >           |
> >      >      >      >>>>
> >       +-------+----------+ |
> >      >      >      >>>>                                 >>>
> >     | |
> >      >     Overlay
> >      >      >      >>>>                                 Module  | |
> >       | |
> >      >     Overlay
> >      >      >      >>>>                                 Module  | |
> >      >      >      >>>>                                 >>>
> |
> >      >      >      >>>>
> >       +---------+--------+ |
> >      >           |
> >      >      >      >>>>
> >       +---------+--------+ |
> >      >      >      >>>>                                 >>>
> |
> >      >           |
> >      >      >      >>>>                                     |       |
> >             |
> >      >      >          |
> >      >      >      >>>>                                 >>>       NVE1
>  |
> >      >           |
> >      >      >      >>>>                                     |       |
> >             |
> >      >      >          |
> >      >      >      >>>>                                 NVE2
> >      >      >      >>>>                                 >>>
> |
> >      >      >      >>>>
> >       +--------+-------+  |
> >      >           |
> >      >      >      >>>>
> >       +--------+-------+  |
> >      >      >      >>>>                                 >>>
> >     |  |VNI1
> >      >      >     VNI2  VNI1
> >      >      >      >>>>                                 |  |       |  |
> VNI1
> >      >     VNI2 VNI1
> >      >      >     |  |
> >      >      >      >>>>                                 >>>
> |
> >      >      >      >>>>
> >       +-+-----+----+---+  |
> >      >           |
> >      >      >      >>>>
> >       +-+-----+-----+--+  |
> >      >      >      >>>>                                 >>>
> >     |VAP1|
> >      >     VAP2|    |
> >      >      >      >>>>                                 VAP3 |
> >       |VAP1| VAP2|
> >      >      >       | VAP3|
> >      >      >      >>>>                                 >>>
> >      >      >      >>>>
> >       +----+-----+----+------+
> >      >      >      >>>>
> >        +----+-----+-----+-----+
> >      >      >      >>>>                                 >>>
> >      >       |     |
> >      >      >        |
> >      >      >      >>>>
>  |
> >      >       |     |
> >      >      >      >>>>                                 >>>
> >      >       |     |
> >      >      >        |
> >      >      >      >>>>
>  |
> >      >       |     |
> >      >      >      >>>>                                 >>>
> >      >       |     |
> >      >      >        |
> >      >      >      >>>>
>  |
> >      >       |     |
> >      >      >      >>>>                                 >>>
> >      >      >      >>>>
> >      >      >
> >       -------+-----+----+-------------------+-----+-----+-------
> >      >      >      >>>>                                 >>>
> >      >       |     |
> >      >      >        |
> >      >      >      >>>>                                    Tenant
> |
> >      >       |     |
> >      >      >      >>>>                                 >>>
> >     TSI1 |
> >      >     TSI2|    |
> >      >      >      >>>>                                 TSI3
> >     TSI1| TSI2|
> >      >      >       |TSI3
> >      >      >      >>>>                                 >>>
> >      >     +---+ +---+
> >      >      >      >>>>                                 +---+
> >       +---+
> >      >     +---+
> >      >      >       +---+
> >      >      >      >>>>                                 >>>
> >      >     |TS1| |TS2|
> >      >      >      >>>>                                 |TS3|
> >       |TS4|
> >      >     |TS5|
> >      >      >       |TS6|
> >      >      >      >>>>                                 >>>
> >      >     +---+ +---+
> >      >      >      >>>>                                 +---+
> >       +---+
> >      >     +---+
> >      >      >       +---+
> >      >      >      >>>>                                 >>>
> >      >      >      >>>>                                 >>> To my
> >      >     understanding, the BFD
> >      >      >      >>>>                                 sessions between
> >     NVE1
> >      >     and NVE2 are
> >      >      >      >>>>                                 actually
> >      >      >      >>>>                                 >>> initiated and
> >      >     terminated
> >      >      >     at VAP
> >      >      >      >>>>                                 of NVE.
> >      >      >      >>>>                                 >>>
> >      >      >      >>>>                                 >>> If the
> >     network operator
> >      >      >     want to
> >      >      >      >>>>                                 set up one BFD
> >     session
> >      >     between
> >      >      >     VAP1 of
> >      >      >      >>>>                                 >>> NVE1 and
> VAP1of
> >      >     NVE2, at the
> >      >      >      >>>>                                 same time
> >     another BFD
> >      >     session
> >      >      >      >>>>                                 between VAP3 of
> >      >      >      >>>>                                 >>> NVE1 and
> >     VAP3 of NVE2,
> >      >      >     although
> >      >      >      >>>>                                 the two BFD
> sessions
> >      >     are for
> >      >      >     the same
> >      >      >      >>>>                                 >>> VNI1, I
> >     believe it's
> >      >      >     reasonable,
> >      >      >      >>>>                                 so that's why I
> >     think we
> >      >      >     should allow it
> >      >      >      >>>>
> >      >      >      >>>>
> >      >      >       _______________________________________________
> >      >      >      >>>>                                 nvo3 mailing list
> >      >      >      >>>> [e-mail] <mailto:[e-mail]>
> >     <mailto:[e-mail] <mailto:[e-mail]>>
> >      >     <mailto:[e-mail] <mailto:[e-mail]>
> >     <mailto:[e-mail] <mailto:[e-mail]>>> <mailto:[e-mail]
> >     <mailto:[e-mail]>
> >      >     <mailto:[e-mail] <mailto:[e-mail]>>
> >      >      >     <mailto:[e-mail] <mailto:[e-mail]>
> >     <mailto:[e-mail] <mailto:[e-mail]>>>>
> >      >      >      >>>> https://www.ietf.org/mailman/listinfo/nvo3
> >      >      >      >>>>
> >      >      >
> >      >
> >
>
>