I do assume there is no chance of forwarding the packet. The reason for
specifying it is to be clear what the VTEP is expected to do in that
case. (Which does mean the text has marginal, but non-zero value.)
Yours,
Joel
On 10/31/2019 12:33 PM, Anoop Ghanwani wrote:
What is the definition of management VNI? Is it that there is no VAP
corresponding to that VNI or something else? If there is no VAP, then
there is no chance of forwarding such packets anyway.
Anoop
On Thu, Oct 31, 2019 at 9:22 AM Jeffrey Haas <jh...@pfrc.org
<mailto:jh...@pfrc.org>> wrote:
I also agree with Joel.
-- Jeff
> On Oct 31, 2019, at 11:59 AM, Joel M. Halpern
<j...@joelhalpern.com <mailto:j...@joelhalpern.com>> wrote:
>
> Explicitly restricting the discard behavior to the management VNI
takes care of my concern.
>
> Thank you,
> Joel
>
> On 10/31/2019 11:48 AM, Greg Mirsky wrote:
>> Hi Jeff,
>> thank you for the detailed clarification of your questions.
Please find my follow-up notes in-lined tagged GIM2>>.
>> Regards,
>> Greg
>> On Wed, Oct 30, 2019 at 2:14 PM Jeffrey Haas <jh...@pfrc.org
<mailto:jh...@pfrc.org> <mailto:jh...@pfrc.org
<mailto:jh...@pfrc.org>>> wrote:
>> Greg,
>> On Wed, Oct 30, 2019 at 01:58:30PM -0700, Greg Mirsky wrote:
>> > On Wed, Oct 30, 2019 at 1:27 PM Jeffrey Haas
<jh...@pfrc.org <mailto:jh...@pfrc.org>
>> <mailto:jh...@pfrc.org <mailto:jh...@pfrc.org>>> wrote:
>> >
>> > > Greg,
>> > >
>> > > From the updated text:
>> > >
>> > > "At the same time, a service layer BFD session may be used
>> between the
>> > > tenants of VTEPs IP1 and IP2 to provide end-to-end fault
>> management. In
>> > > such case, for VTEPs BFD Control packets of that session are
>> > > indistinguishable from data packets. If end-to-end defect
>> detection is
>> > > realized as the set of concatenated OAM domains, e.g.,
VM1-1 -
>> IP1 --
>> > > IP2 - VM2-1, then the BFD session over VXLAN between
VTEPs SHOULD
>> > > follow the procedures described in Section 6.8.17
[RFC5880]."
>> > >
>> > > In the case that two VMs are running BFD to each other
as a user
>> > > application
>> > > rather than as part of the virtualized environment, it's
>> unlikely that
>> > > they'd be treated as concatenated domains. To do so, the
>> tenant VMs would
>> > > have to have a sense that they are indeed virtual.
>> > >
>> > > Is your intent in this text that BFD implementations on the
>> server should
>> > > detect BFD sessions between servers and change them to a
>> concatenated
>> > > session?
>> > >
>> > GIM>> No, we do not suggest that the concatenation of BFD
sessions be
>> > automagical. That may be controlled via the management
plane though.
>> Then my suggestion is we may not want this text.
>> It's fine to say "if tenants want to run BFD to each other,
and that is
>> standard BFD (RFC 5881) from the perspective of those
tenants" if that's
>> your intent. Leave automagic out of the spec. :-)
>> GIM2>> I'd take the passage referring to the concatenated path
out. That will leave it as:
>> At the same time, a service layer BFD session may be used
between the
>> tenants of VTEPs IP1 and IP2 to provide end-to-end fault
management.
>> In such case, for VTEPs BFD Control packets of that session are
>> indistinguishable from data packets.
>> > > Section 5 comment:
>> > >
>> > > : The UDP destination port and the TTL of the inner IP
packet
>> MUST be
>> > > : validated to determine if the received packet can be
>> processed by
>> > > : BFD. BFD Control packets with unknown MAC address
MUST NOT be
>> > > : forwarded to VMs.
>> > >
>> > > I'd suggest pushing the second sentence into the prior
section
>> since it
>> > > deals with MAC addresses rather than the UDP procedures.
>> > >
>> > GIM>> Could you please clarify your suggestion - move to
Section
>> 4 or to
>> > the preceding paragraph? I think it is the latter but
wanted to
>> make sure.
>> Full section 5 from your draft-8 candidate:
>> : 5. Reception of BFD Packet from VXLAN Tunnel
>> :
>> : Once a packet is received, the VTEP MUST validate the
packet. If the
>> : Destination MAC of the inner Ethernet frame matches one
of the MAC
>> : addresses associated with the VTEP the packet MUST be
processed
>> : further. If the Destination MAC of the inner Ethernet frame
>> doesn't
>> : match any of VTEP's MAC addresses, then the processing
of the
>> : received VXLAN packet MUST follow the procedures
described in
>> : Section 4.1 [RFC7348].
>> It's not clear what that procedure is, with respect to BFD.
Section 4.1
>> basically says is that when a mapping is discovered, deliver
it to
>> that VM
>> with headers removed.
>> Section 4.1 really doesn't discuss dropping behavior.
>> :
>> : The UDP destination port and the TTL of the inner IP
packet MUST be
>> : validated to determine if the received packet can be
processed by
>> : BFD.
>> This is fine.
>> : BFD Control packets with unknown MAC address MUST NOT be
>> : forwarded to VMs.
>> This appears to be clarifying the missing point in the prior
>> paragraph. If
>> that's the case, why is this sentence not part of the prior
paragraph?
>> GIM>> So I thought. Moving the sentence to the first paragraph
highlighted the contradiction others had pointed earlier:
>> On the one hand:
>> If the Destination MAC of the inner Ethernet frame doesn't
>> match any of VTEP's MAC addresses, then the processing of the
>> received VXLAN packet MUST follow the procedures described in
>> Section 4.1 [RFC7348].
>> To which we add:
>> BFD Control packets with unknown MAC address
>> MUST NOT be forwarded to VMs.
>> But the unknown MACs are treated as BUM according to the last
paragraph in Section 4.2 of RFC 7348:
>> Note that multicast frames and "unknown MAC destination"
frames are
>> also sent using the multicast tree, similar to the broadcast
frames.
>> In light of that, can this draft require that BFD packets with
unknown MAC be dropped and not flooded over the corresponding to the
VNI domain? I think that in addition to moving the sentence up the
statement must be updated:
>> OLD TEXT:
>> BFD Control packets with unknown MAC address
>> MUST NOT be forwarded to VMs.
>> NEW TEXT:
>> If the BFD session is using the Management VNI (Section 6),
>> BFD Control packets with unknown MAC address
>> MUST NOT be forwarded to VMs.
>> Comments? Suggestions?
>> -- Jeff
