Re: [bess] WGLC, IPR and implementation poll on draft-ietf-bess-evpn-mh-pa-02

Hello WG,

There is a draft published couple of months back and talks about All-PEs (attached to a segment) elected as DFs and a corresponding use case to do so.
https://datatracker.ietf.org/doc/draft-saumvinayak-bess-all-df-bum/
I think a discussion is needed before proceeding with draft-ietf-bess-evpn-mh-pa

A new version of I-D, draft-saumvinayak-bess-all-df-bum-00.txt

has been successfully submitted by Saumya Dikshit and posted to the IETF repository.

Name:                 draft-saumvinayak-bess-all-df-bum

Revision:            00

Title:                    EVPN Mac Dampening Back-off

Document date:              2021-09-03

Group:                Individual Submission

Pages:                 7

Abstract:

   The Designated forwarder concept is leveraged to prevent looping of

   BUM traffic into tenant network sourced across NVO fabric for

   multihoming deployments.  [RFC7432] defines a prelimnary approach to

   select the DF for an ES,VLAN or ES,Vlan Group panning across multiple

   NVE's.  [RFC8584] makes the election logic more robust and fine

   grained inculcating fair election of DF handling most of the

   prevalent use-cases.  This document presents a deployment problem and

   a corresponding solution which cannot be easily resolve by rules

   mentioned in [RFC7432] and [RFC8584].

From: BESS [mailto:bess-bounces@ietf.org] On Behalf Of Anoop Ghanwani
Sent: Tuesday, November 9, 2021 8:45 PM
To: Patrice Brissette (pbrisset) <pbrisset@cisco.com>
Cc: bess-chairs@ietf.org; Luc André Burdet <laburdet.ietf@gmail.com>; slitkows.ietf@gmail.com; BESS <bess@ietf.org>
Subject: Re: [bess] WGLC, IPR and implementation poll on draft-ietf-bess-evpn-mh-pa-02

Patrice,

The one at the very top of the thread:

>>>
Would it be possible to add a line in section 4 along the lines of:

"While the various algorithms for DF election are discussed in Sections 4.2-4.4, unlike all-active load balancing, the choice of algorithm in this solution doesn't impact performance in any way since there is only one active link."
>>>
I think adding the above line will make it clear that the choice of the algorithm for single active is inconsequential in terms of performance.

Anoop

On Tue, Nov 9, 2021 at 6:49 AM Patrice Brissette (pbrisset) <pbrisset@cisco.com<mailto:pbrisset@cisco.com>> wrote:
Anoop,

Which specifics haven’t we answer?

Regards,
Patrice Brissette, Principal Engineer
Cisco Systems

http://e-vpn.io<http://e-vpn.io>
http://go2.cisco.com/evpn<http://go2.cisco.com/evpn>

From: BESS <bess-bounces@ietf.org<mailto:bess-bounces@ietf.org>> on behalf of Anoop Ghanwani <anoop@alumni.duke.edu<mailto:anoop@alumni.duke.edu>>
Date: Tuesday, November 9, 2021 at 09:48
To: "slitkows.ietf@gmail.com<mailto:slitkows.ietf@gmail.com>" <slitkows.ietf@gmail.com<mailto:slitkows.ietf@gmail.com>>
Cc: Luc André Burdet <laburdet.ietf@gmail.com<mailto:laburdet.ietf@gmail.com>>, "bess-chairs@ietf.org<mailto:bess-chairs@ietf.org>" <bess-chairs@ietf.org<mailto:bess-chairs@ietf.org>>, BESS <bess@ietf.org<mailto:bess@ietf.org>>
Subject: Re: [bess] WGLC, IPR and implementation poll on draft-ietf-bess-evpn-mh-pa-02

Hi Stefane,

Yes, the document is much improved.  There's the last exchange below which I didn't get a response to.  I think that would help convey the intent of the authors more clearly.

Thanks,
Anoop

On Mon, Nov 8, 2021 at 4:01 AM <slitkows.ietf@gmail.com<mailto:slitkows.ietf@gmail.com>> wrote:
Anoop,

Could you confirm that you are fine with the changes proposed by Luc, so we can move the draft forward to next steps ?

Thanks !

From: Anoop Ghanwani <anoop@alumni.duke.edu<mailto:anoop@alumni.duke.edu>>
Sent: lundi 5 juillet 2021 21:39
To: Luc André Burdet <laburdet.ietf@gmail.com<mailto:laburdet.ietf@gmail.com>>
Cc: slitkows.ietf@gmail.com<mailto:slitkows.ietf@gmail.com>; bess-chairs@ietf.org<mailto:bess-chairs@ietf.org>; BESS <bess@ietf.org<mailto:bess@ietf.org>>
Subject: Re: [bess] WGLC, IPR and implementation poll on draft-ietf-bess-evpn-mh-pa-02

Thanks Luc.

Would it be possible to add a line in section 4 along the lines of:

"While the various algorithms for DF election are discussed in Sections 4.2-4.4, unlike all-active load balancing, the choice of algorithm in this solution doesn't impact performance in any way since there is only one active link."

Anoop

On Mon, Jul 5, 2021 at 11:31 AM Luc André Burdet <laburdet.ietf@gmail.com<mailto:laburdet.ietf@gmail.com>> wrote:
Thank you for your careful review Anoop;
I have uploaded -03 which I believe addresses all comments.

Regarding the section specifying procedures for all DF Election algorithms: it is included per a previous review comment, primarily to be comprehensive for all existing DF Algos.  I agree the result may generally not vary much but the details of the procedure need to be specified. I hope this clears up any confusion.

Regards,
Luc André

Luc André Burdet |  Cisco  |  laburdet.ietf@gmail.com<mailto:laburdet.ietf@gmail.com>  |  Tel: +1 613 254 4814

From: BESS <bess-bounces@ietf.org<mailto:bess-bounces@ietf.org>> on behalf of Anoop Ghanwani <anoop@alumni.duke.edu<mailto:anoop@alumni.duke.edu>>
Date: Tuesday, June 1, 2021 at 19:23
To: "slitkows.ietf@gmail.com<mailto:slitkows.ietf@gmail.com>" <slitkows.ietf@gmail.com<mailto:slitkows.ietf@gmail.com>>
Cc: "bess-chairs@ietf.org<mailto:bess-chairs@ietf.org>" <bess-chairs@ietf.org<mailto:bess-chairs@ietf.org>>, BESS <bess@ietf.org<mailto:bess@ietf.org>>
Subject: Re: [bess] WGLC, IPR and implementation poll on draft-ietf-bess-evpn-mh-pa-02

I support publication of this document.  The following are my comments.

==
Abstract

- I think it would be better to list the RFC rather than say "EVPN standard", since EVPN standard is an evolving term.
- "support of port-active" -> "support for port-active"

- The last line of the abstract should be moved to the introduction.

Section 1

- "The determinism provided by active-standby per interface is also required for certain QOS features to work."
  Can you provide an example of this?
- Change
"A new term of load-balancing mode, port-active load- balancing is then defined."
to
"A new load-balancing mode, port-active load-balancing is defined."

- Change
"This draft describes how that new redundancy mode can be supported via EVPN"
to
"This draft describes how that new load balancing mode can be supported via EVPN"
(Just for consistency, I think it would be better to search the doc throughout and make sure that "redundancy" is not being used in place of "load balancing", since we are defining a new load balancing method, not a new redundancy method/topology.)

- Is "Bundle-Ethernet interfaces" a well-known term?  I think it may be better to drop Bundle.  I am not sure if what is meant here is "members of a LAG".

- "multi-homing to CE" -> "multi-homing to the CE".

Section 2

- Change
"form a bundle and operate as a Link Aggregation Group (LAG)"
to
"form and operate as a Link Aggregation Group (LAG)"
(In EVPN bundling normally refers to many:1 mapping of VLAN to VNI/service instance).

- Include reference for ICCP.

- Change
"CE device connected to Multi-homing PEs may has"
to
"CE device connected to multi-homing PEs may have"

- Change
"Links in the Ethernet Bundle"
to
"links in the LAG"

- Change
"Any discrepancies from this list is left for future study."
to
"Any discrepancies from this list are left for future study."

Section 3

- Missing period at the end of (b).

- Layer2 attributes -> Layer-2 attributes.

Section 4.2/4.3

I got a bit confused here.  The draft discusses Modulo, HRW.  Do we essentially end up with a single active link, but just that which link is chosen is dependent on the algorithm?  If so, what is the benefit of doing so?  I can see why multiple algorithms are of value when we are doing VLAN-based load balancing to multiple active links.

Section 5

- "Bundle-Ethernet" -> "LAG"

Section 5.1

- "per ES routes for fast convergence" -> "per ES route for fast convergence"

Section 5.2

- "per EVI routes" -> "per EVI route"

Section 7

- spurious 'g'.

- missing period under the second sub-bullet of point 'f'.

On Mon, May 31, 2021 at 12:31 AM <slitkows.ietf@gmail.com<mailto:slitkows.ietf@gmail.com>> wrote:

Hello WG,

This email starts a two weeks Working Group Last Call on

draft-ietf-bess-evpn-mh-pa-02 [1].

This poll runs until * the 7th of June *.

We are also polling for knowledge of any undisclosed IPR that applies to

this Document, to ensure that IPR has been disclosed in compliance with IETF

IPR rules (see RFCs 3979, 4879, 3669 and 5378 for more details).

If you are listed as an Author or a Contributor of this Document please

respond to this email and indicate whether or not you are aware of any

relevant undisclosed IPR. The Document won't progress without answers from

all the Authors and Contributors.

There is currently no IPR disclosed.

If you are not listed as an Author or a Contributor, then please explicitly

respond only if you are aware of any IPR that has not yet been disclosed in

conformance with IETF rules.

We are also polling for any existing implementation as per [2].

Thank you,

Stephane & Matthew

[1]

https://datatracker.ietf.org/doc/draft-ietf-bess-evpn-mh-pa/<https://datatracker.ietf.org/doc/draft-ietf-bess-evpn-mh-pa/>

[2] https://mailarchive.ietf.org/arch/msg/bess/cG3X1tTqb_vPC4rg56SEdkjqDpw<https://mailarchive.ietf.org/arch/msg/bess/cG3X1tTqb_vPC4rg56SEdkjqDpw>

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