Subject: Opsdir telechat review of draft-ietf-bfd-vxlan-09

From: Jürgen Schönwälder via Datatracker <[email-masked]>
Date: Tue, 17 Dec 2019 00:05:23 -0800

Reviewer: Jürgen Schönwälder
Review result: Has Nits

I have only a limited understanding of VXLAN and BFD technology.
Hence, some of my question may look odd to the insiders.

- Never	heard of this IPv6 loopback address space before. Is it	OK to
  allocate and use it this way?

- Why is echo BFD outside the scope of this document? Can I just turn
  on echo mode or will extra specifications be needed?

- Nits:

  OLD

    Ability to monitor path continuity

  NEW

    The ability to monitor path continuity

  OLD

    BFD packet MUST be encapsulated

  NEW

    BFD packets MUST be encapsulated

---

From: Greg Mirsky <[email-masked]>
Date: Tue, 17 Dec 2019 14:53:37 -0800

Hi Jurgen,
thank you for the review, questions, and suggestions to improve the
document. I've applied the changes to the working version of the draft. The
attached diff highlights the updates (including those suggested by Adam).
Please find my notes in-line tagged GIM>>,

Best regards,
Greg

>   allocate and use it this way?
GIM>> As Adam had explained, the correct wording for these addresses (and
that is what used in the working version) is "IPv4-mapped IPv4 loopback
addresses". Using an address from this range as the destination IP address
of an OAM packet encapsulated in a tunnel was, to the best of my knowledge,
first defined in RFC 4379 (now RFC 8029). Then RFC 5884 applied it to BFD
over MPLS LSP.

>   on echo mode or will extra specifications be needed?
GIM>> I believe that the support of the Echo mode of BFD has not been
requested by the BFD WG. I think that some amount of work to define the use
of Echo BFD over VXLAN may be needed.

---

From: Santosh P K <[email-masked]>
Date: Fri, 27 Dec 2019 20:57:49 +0530

Hello,
     Please see my inline comments tagged [SPK].

>   allocate and use it this way?

[SPK] We have received suggestions from other IESG review we coming up with
text which will address this.

>   on echo mode or will extra specifications be needed?

[SPK] Echo BFD to work we need destination IP address to be set to sending
VTEP address so that BFD packet is looped back when VTEP decapsulate VXLAN
header. Currently VTEP IP address may be used by tenant and hence this
needs more discussion and may need extension document. We have kept the
scope limited to async BFD for this document.