Thank you for the follow up Eric,

At least from draft-ietf-nvo3-geneve-oam perspective a fresh LC seems 
appropriate.

The sequencing of events depends upon which draft Greg wants to use to get the 
IANA IP address related code-points. Greg, would you have an early insight on 
how you prefer to progress?

G/

From: Eric Vyncke (evyncke) <evyncke=40cisco....@dmarc.ietf.org>
Sent: Tuesday, January 14, 2025 2:50 PM
To: Greg Mirsky <gregimir...@gmail.com>; The IESG <i...@ietf.org>
Cc: draft-ietf-mpls-p2mp-...@ietf.org; m...@ietf.org; NVO3 <nvo3@ietf.org>; 
nvo3-cha...@ietf.org; draft-ietf-nvo3-geneve-...@ietf.org
Subject: Re: Éric Vyncke's Discuss on draft-ietf-mpls-p2mp-bfd-08: (with 
DISCUSS and COMMENT)


CAUTION: This is an external email. Please be very careful when clicking links 
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Greg,

I am perfectly fine with option #2 (even if option #3 is nicer from my INT AD 
point of view), i.e., one I-D is requesting the IPv4/IPv6 prefixes with the 
right wording in its IANA section and the other I-D has some text about 
re-using those prefixes with a normative reference to the 1st I-D (plus some 
notes to the RFC editor to copy the selected prefixes).

Now, these two I-Ds are in the routing area, so, it is also up to the RTG ADs 
to express their preferences and decide whether a new IETF Last Call is 
required (as this is an important technical change in the I-Ds).

I understand that this is more work for many people and some delays, but the 
final I-Ds will be much more elegant and no more violating RFC 4291 😊 Hence, I 
will clear my DISCUSS position.

Regards

-éric

From: Greg Mirsky <gregimir...@gmail.com<mailto:gregimir...@gmail.com>>
Date: Friday, 10 January 2025 at 23:14
To: Eric Vyncke (evyncke) <evyn...@cisco.com<mailto:evyn...@cisco.com>>
Cc: The IESG <i...@ietf.org<mailto:i...@ietf.org>>, 
draft-ietf-mpls-p2mp-...@ietf.org<mailto:draft-ietf-mpls-p2mp-...@ietf.org> 
<draft-ietf-mpls-p2mp-...@ietf.org<mailto:draft-ietf-mpls-p2mp-...@ietf.org>>, 
mpls-cha...@ietf.org<mailto:mpls-cha...@ietf.org> 
<mpls-cha...@ietf.org<mailto:mpls-cha...@ietf.org>>, 
m...@ietf.org<mailto:m...@ietf.org> <m...@ietf.org<mailto:m...@ietf.org>>, 
n.leym...@telekom.de<mailto:n.leym...@telekom.de> 
<n.leym...@telekom.de<mailto:n.leym...@telekom.de>>, NVO3 
<nvo3@ietf.org<mailto:nvo3@ietf.org>>, 
nvo3-cha...@ietf.org<mailto:nvo3-cha...@ietf.org> 
<nvo3-cha...@ietf.org<mailto:nvo3-cha...@ietf.org>>, 
draft-ietf-nvo3-geneve-...@ietf.org<mailto:draft-ietf-nvo3-geneve-...@ietf.org> 
<draft-ietf-nvo3-geneve-...@ietf.org<mailto:draft-ietf-nvo3-geneve-...@ietf.org>>,
 Bocci, Matthew (Nokia - GB) 
<matthew.bo...@nokia.com<mailto:matthew.bo...@nokia.com>>
Subject: Re: Éric Vyncke's Discuss on draft-ietf-mpls-p2mp-bfd-08: (with 
DISCUSS and COMMENT)
Hi Eric,
Thank you for the detailed explanation of all options to conclude the work of 
two WGs on these documents properly. I think that Option #2 is reasonable and 
will work on updating drafts accordingly. In the meantime, I appreciate your 
thoughts on where to request IANA. Would it be acceptable if such a request is 
expressed in one document, e.g., draft-ietf-mpls-p2mp-bfd, and the other 
document uses a Normative reference to that draft? If that is acceptable, we 
will avoid any possibility of duplication of the IANA part.

Regards,
Greg

On Fri, Jan 10, 2025 at 2:36 AM Eric Vyncke (evyncke) 
<evyn...@cisco.com<mailto:evyn...@cisco.com>> wrote:
Greg,

Thank you for merging the two threads, very sensible action as the two IETF 
drafts have the same issue.

The IESG discussed it during the 9th of January telechat, and there are at 
least three solutions (all allowing for ECMP probing):


1.      Using the 100::/64 prefix (as you wrote it was not published when the 
original RFC were published), easy, immediate solution for IPv6, but not for 
IPv4

2.      The MPLS/NVO3 drafts add an IANA section requesting an IPv6 /64 prefix 
and an IPv4 /24 prefix for this specific use (with a note about avoiding 
duplicates), similar future documents could then refer to either the MPLS/NVO3 
RFC

3.      A short/quick (AD-sponsored ?) IETF draft requesting the IPv6 /64 and 
an IPv4 / 24 prefixes for similar use cases, way nicer and easier reference for 
similar future documents

In all cases, I am afraid that an IETF Last Call & IESG evaluation should be 
done again as it is a not a minor editorial change.

Early allocation could be requested for 2) and 3) within weeks.

For 3) the MPLS/NVO3 documents could be quickly approved by the IESG with a 
normative reference to the short draft.

Even if I mostly care about IPv6, I think that a solution for IPv4 is 
important. The solution 3) is much nicer albeit probably causing delays in 
*publication* of the MPLS/NVO3 drafts but not for their *approvals*.

On my side, 3) is the best way forward, but happy to listen to the community 
feedback

Regards

-éric

From: Greg Mirsky <gregimir...@gmail.com<mailto:gregimir...@gmail.com>>
Date: Thursday, 9 January 2025 at 22:04
To: Eric Vyncke (evyncke) <evyn...@cisco.com<mailto:evyn...@cisco.com>>
Cc: The IESG <i...@ietf.org<mailto:i...@ietf.org>>, 
draft-ietf-mpls-p2mp-...@ietf.org<mailto:draft-ietf-mpls-p2mp-...@ietf.org> 
<draft-ietf-mpls-p2mp-...@ietf.org<mailto:draft-ietf-mpls-p2mp-...@ietf.org>>, 
mpls-cha...@ietf.org<mailto:mpls-cha...@ietf.org> 
<mpls-cha...@ietf.org<mailto:mpls-cha...@ietf.org>>, 
m...@ietf.org<mailto:m...@ietf.org> <m...@ietf.org<mailto:m...@ietf.org>>, 
n.leym...@telekom.de<mailto:n.leym...@telekom.de> 
<n.leym...@telekom.de<mailto:n.leym...@telekom.de>>, NVO3 
<nvo3@ietf.org<mailto:nvo3@ietf.org>>, 
nvo3-cha...@ietf.org<mailto:nvo3-cha...@ietf.org> 
<nvo3-cha...@ietf.org<mailto:nvo3-cha...@ietf.org>>, 
nvo3-...@ietf.org<mailto:nvo3-...@ietf.org> 
<nvo3-...@ietf.org<mailto:nvo3-...@ietf.org>>, 
draft-ietf-nvo3-geneve-...@ietf.org<mailto:draft-ietf-nvo3-geneve-...@ietf.org> 
<draft-ietf-nvo3-geneve-...@ietf.org<mailto:draft-ietf-nvo3-geneve-...@ietf.org>>,
 Bocci, Matthew (Nokia - GB) 
<matthew.bo...@nokia.com<mailto:matthew.bo...@nokia.com>>
Subject: Re: Éric Vyncke's Discuss on draft-ietf-mpls-p2mp-bfd-08: (with 
DISCUSS and COMMENT)
Merging two discussions might help us reach an acceptable solution.

Regards,
Greg

On Thu, Jan 9, 2025 at 10:28 AM Greg Mirsky 
<gregimir...@gmail.com<mailto:gregimir...@gmail.com>> wrote:
Hi Eric,
thank you for the discussion and further clarification of your concern with the 
proposed use of ::1/128 as the inner destination IPv6 address in tunneled 
active OAM packets. Please see my follow-up notes below tagged GIM2>>.

Regards,
Greg

On Thu, Jan 9, 2025 at 5:35 AM Eric Vyncke (evyncke) 
<evyn...@cisco.com<mailto:evyn...@cisco.com>> wrote:
Hello Greg,

Thanks for your reply.

A quick and easy point first: my comment on section 3.1 is really 
s\0:0:0:0:0:FFFF:7F00/104\::ffff:7f00/104\ or 
\::ffff:127.0.0.0/104\<http://127.0.0.0/104%5C> (and no need to add a reference 
to RFC 5952). Sorry if I was unclear in my comment.
GIM2>> Thank you for the clarification. I used the first option, changing 'F' 
into 'f'.

This leads of course to the core of my DISCUSS: using ::1 as the inner 
destination address to avoid the dummy inner packet to be consumed by a 
non-intended recipient. Like ::ff00:127.0.0.0/104<http://127.0.0.0/104> it is a 
violation of RFC 4291 even if slightly nicer.

Did the MPLS WG consider the use of RFC 6666 (discard prefix) 100::/64 ? This 
would also have the benefit of allowing entry in the destination address to 
allow for ECMP testing.
GIM2>> Thank you for pointing out this option. AFAIK when the first RFC, RFC 
4379, was published defining IP/UDP encapsulation of active OAM packets in the 
MPLS network, the IPv6 range was not assigned yet. Also, RFC 
9570<https://datatracker.ietf.org/doc/rfc9570/> recommends using ::1/128 as the 
inner destination IPv6 address in IP/UDP encapsulation of an active OAM packet 
in the MPLS network. I believe using an IPv6 address in IP/UDP encapsulation 
must be consistent across all cases, whether MPLS or IPv6 tunneling.

E.g., the following text would be better IMHO (keeping the 2nd bullet to 
support legacy implementations):

“This document updates Section 5.8 of 
[RFC8562<https://www.rfc-editor.org/info/rfc8562>] regarding the selection of 
the IPv6 destination address:
•         The sender of an echo request SHOULD select the IPv6 destination from 
the 100::/64 RFC 6666 prefix.
•         The sender of an echo request MAY select the IPv6 destination address 
from the 0:0:0:0:0:FFFF:7F00/104 prefix.”
Alternatively, IANA could easily assign another /64 for the use of BFD.
GIM2>> As this issue is present in both documents, draft-ietf-mpls-p2mp-bfd, 
and draft-ietf-nvo3-geneve-oam, I defer to ADs and WG Chairs for their 
suggestions and guidance.

Regards

-éric

From: Greg Mirsky <gregimir...@gmail.com<mailto:gregimir...@gmail.com>>
Date: Monday, 6 January 2025 at 20:49
To: Eric Vyncke (evyncke) <evyn...@cisco.com<mailto:evyn...@cisco.com>>
Cc: The IESG <i...@ietf.org<mailto:i...@ietf.org>>, 
draft-ietf-mpls-p2mp-...@ietf.org<mailto:draft-ietf-mpls-p2mp-...@ietf.org> 
<draft-ietf-mpls-p2mp-...@ietf.org<mailto:draft-ietf-mpls-p2mp-...@ietf.org>>, 
mpls-cha...@ietf.org<mailto:mpls-cha...@ietf.org> 
<mpls-cha...@ietf.org<mailto:mpls-cha...@ietf.org>>, 
m...@ietf.org<mailto:m...@ietf.org> <m...@ietf.org<mailto:m...@ietf.org>>, 
n.leym...@telekom.de<mailto:n.leym...@telekom.de> 
<n.leym...@telekom.de<mailto:n.leym...@telekom.de>>
Subject: Re: Éric Vyncke's Discuss on draft-ietf-mpls-p2mp-bfd-08: (with 
DISCUSS and COMMENT)
Hi Éric,
thank you for your review and comments. Please find my notes below tagged 
GIM>>. The attached diff highlights updates applied in the new working version.

Regards,
Greg

On Mon, Jan 6, 2025 at 4:13 AM Éric Vyncke via Datatracker 
<nore...@ietf.org<mailto:nore...@ietf.org>> wrote:
Éric Vyncke has entered the following ballot position for
draft-ietf-mpls-p2mp-bfd-08: Discuss

When responding, please keep the subject line intact and reply to all
email addresses included in the To and CC lines. (Feel free to cut this
introductory paragraph, however.)


Please refer to 
https://www.ietf.org/about/groups/iesg/statements/handling-ballot-positions/
for more information about how to handle DISCUSS and COMMENT positions.


The document, along with other ballot positions, can be found here:
https://datatracker.ietf.org/doc/draft-ietf-mpls-p2mp-bfd/



----------------------------------------------------------------------
DISCUSS:
----------------------------------------------------------------------


# Éric Vyncke, INT AD, comments for draft-ietf-mpls-p2mp-bfd-08
CC @evyncke

Thank you for the work put into this document.

Please find below one blocking DISCUSS points, some non-blocking COMMENT points
(but replies would be appreciated even if only for my own education), and some
nits.

Special thanks to Nicolai Leymann for the shepherd's detailed write-up
including the WG consensus *but it lacks* the justification of the intended
status.

I hope that this review helps to improve the document,

Regards,

-éric

## DISCUSS (blocking)

As noted in https://www.ietf.org/blog/handling-iesg-ballot-positions/, a
DISCUSS ballot is just a request to have a discussion on the following topics:

### Section 3.1

Happy to stand corrected, but I read section 3.1 as IP packets are sent outside
of a node on a real (p2mp) link with a destination address of ::1/128. If
confirmed, then this is an apparent violation of section 2.5.3 of RFC 4291
(even if sent over MPLS).
GIM>> The use of a loopback IP address as the destination in MPLS-encapsulated 
IP/UDP was introduced in RFC 4379 (it was obsoleted by RFC 
8029<https://datatracker.ietf.org/doc/html/rfc8029>). In it, the use of a 
loopback discussed in Section 2.1. Use of a loopback IPv4 address as the 
destination address in MPLS-encapsulated IP/UDP active OAM, e.g., LSP Echo 
request/reply (RFC 8029) or BFD (RFC 5884), as I understand is accepted and 
broadly deployed. This document is intended to correct earlier misconception 
about IPv6-mapped IPv4 loopback address range and recommends using IPv6 
loopback as the destination address in IP/UDP encapsulation over MPLS.

I understand that this violation started already in RFC 8562, and I have no
obvious solution to propose except using a link-local mcast address, e.g.,
ff02::2/128 (all link routers).
GIM>> The intention of using a loopback address as the IP destination address 
in IP/UDP encapsulation of an active OAM over MPLS discussed in Section 2.1 of 
RFC 8029<https://datatracker.ietf.org/doc/html/rfc8029#section-2.1>:
   1.  Although the LSP in question may be broken in unknown ways, the
       likelihood of a diagnostic packet being delivered to a user of an
       MPLS service MUST be held to an absolute minimum.

   2.  If an LSP is broken in such a way that it prematurely terminates,
       the diagnostic packet MUST NOT be IP forwarded.

   3.  A means of varying the diagnostic packets such that they exercise
       all ECMP paths is thus REQUIRED.
It seems like using link-local mcast address would not comply to these 
requirements, but a loopback address is complying.


----------------------------------------------------------------------
COMMENT:
----------------------------------------------------------------------


## COMMENTS (non-blocking)

### Abstract and Section 1

s/recommends the use of *an* IPv6 loopback address/recommends the use of *the*
IPv6 loopback address/
GIM>> Thank you; done.

### Section 2.1

Suggest adding a reference (or a definition) of `G-ACh`.
GIM>> Added reference to RFC 5586 in Section 3.2 and expanded on the first use 
of the abbreviation.

### Section 3.1

Please use section 5 of RFC 5952 for `0:0:0:0:0:FFFF:7F00/104`.
GIMM>> Added as Informative reference. Would you agree?

### Section 3.2

In figure 1, some fields have a length that is specified and others have no
length... Is it on purpose ?
GIM>> Thank you for pointing that out to me. I removed occurences of '(16 
bits)'.

Even if the reader could guess, what are the expected sender/receiver behavior
for the reserved fields ?
GIM>> The Source Address TLV is defined in Section 4.1 of RFC 
7212<https://www.rfc-editor.org/rfc/rfc7212.html>. Would you recommend 
clarificaton of how its fields are handled?

## NITS (non-blocking / cosmetic)

### Use of SVG graphics

To make a much nicer HTML rendering, suggest using the aasvg too to generate
SVG graphics. It is worth a try ;-)
GIM>> I will try it ;)
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