Re: Éric Vyncke's Discuss on draft-ietf-bfd-vxlan-09: (with DISCUSS and COMMENT)
Jeffrey Haas <jhaas@pfrc.org> Wed, 18 December 2019 20:27 UTC
Return-Path: <jhaas@slice.pfrc.org>
X-Original-To: rtg-bfd@ietfa.amsl.com
Delivered-To: rtg-bfd@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 2D8F4120C17; Wed, 18 Dec 2019 12:27:18 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.901
X-Spam-Level:
X-Spam-Status: No, score=-1.901 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id OqBVjV-566sk; Wed, 18 Dec 2019 12:27:16 -0800 (PST)
Received: from slice.pfrc.org (slice.pfrc.org [67.207.130.108]) by ietfa.amsl.com (Postfix) with ESMTP id 33457120C15; Wed, 18 Dec 2019 12:27:16 -0800 (PST)
Received: by slice.pfrc.org (Postfix, from userid 1001) id 174961E2F6; Wed, 18 Dec 2019 15:31:46 -0500 (EST)
Date: Wed, 18 Dec 2019 15:31:45 -0500
From: Jeffrey Haas <jhaas@pfrc.org>
To: "Carlos Pignataro (cpignata)" <cpignata@cisco.com>
Cc: "Eric Vyncke (evyncke)" <evyncke@cisco.com>, The IESG <iesg@ietf.org>, "draft-ietf-bfd-vxlan@ietf.org" <draft-ietf-bfd-vxlan@ietf.org>, "rtg-bfd@ietf.org" <rtg-bfd@ietf.org>, "bfd-chairs@ietf.org" <bfd-chairs@ietf.org>
Subject: Re: Éric Vyncke's Discuss on draft-ietf-bfd-vxlan-09: (with DISCUSS and COMMENT)
Message-ID: <20191218203145.GD6488@pfrc.org>
References: <157657269782.26511.12421406428553874826.idtracker@ietfa.amsl.com> <CED2B858-AC55-4B0A-ADA2-AC46B628E6DA@cisco.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="utf-8"
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <CED2B858-AC55-4B0A-ADA2-AC46B628E6DA@cisco.com>
User-Agent: Mutt/1.5.21 (2010-09-15)
Archived-At: <https://mailarchive.ietf.org/arch/msg/rtg-bfd/BMW8_RKVJMSUa0Q8LMx9inVe83o>
X-BeenThere: rtg-bfd@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: "RTG Area: Bidirectional Forwarding Detection DT" <rtg-bfd.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/rtg-bfd>, <mailto:rtg-bfd-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/rtg-bfd/>
List-Post: <mailto:rtg-bfd@ietf.org>
List-Help: <mailto:rtg-bfd-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/rtg-bfd>, <mailto:rtg-bfd-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 18 Dec 2019 20:27:18 -0000
Carlos, Éric, Note that I'm not an expert in the underlying MPLS technologies. I'll make two notes: BFD for vxlan is in a similar feature-space as RFC 5884, BFD for MPLS. RFC 5884, section 7, paragraph 3, suggests a TTL of 1 and provides a reference to RFC 4379. RFC 4379, section 4.3, provides procedures for TTL of 1. My personal inference would be that implementations at least in MPLS-land really want the TTL to be 1 for purposes of doing appropriate encapsulation checks. I agree that GTSM procedures would suggest we may want TTL of 255. I suggest the answer we're looking for here would be provided by parties with appropriate history on why RFC 4379 recommends its procedures. Failing that, I suspect BFD for vxlan is no worse than 4379. -- Jeff On Tue, Dec 17, 2019 at 05:17:11PM +0000, Carlos Pignataro (cpignata) wrote: > Hi, Éric, > > Regarding you first DISCUSS element, I had brought up the same issue. See the 2nd point at https://mailarchive.ietf.org/arch/msg/rtg-bfd/BL9Ob66Yxie4wX13yZJELbYPLJs > > Thanks, > > Carlos. > > 2019/12/17 午前3:51、Éric Vyncke via Datatracker <noreply@ietf.org<mailto:noreply@ietf.org>>のメール: > > Éric Vyncke has entered the following ballot position for > draft-ietf-bfd-vxlan-09: 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/iesg/statement/discuss-criteria.html > for more information about IESG DISCUSS and COMMENT positions. > > > The document, along with other ballot positions, can be found here: > https://datatracker.ietf.org/doc/draft-ietf-bfd-vxlan/ > > > > ---------------------------------------------------------------------- > DISCUSS: > ---------------------------------------------------------------------- > > > Thank you for the work put into this document. > > I fully second Adam's COMMENT that should be fixed before publication (IMHO > this is a DISCUSS). > > Answers to my COMMENTs below will be welcome, even if those COMMENTs are not > blocking. > > As usual, an answer to the DISCUSS is required to clear my DISCUSS though. > > I hope that this helps to improve the document, > > Regards, > > -éric > > == DISCUSS == > > May be I am not familiar enough with BFD, but, RFC 5881 (the one defining BFD) > specifies the use of TTL = Hop Limit = 255.. Why this document uses a value of > 1 ? > > -- Section 3 -- > IPv4-mapped IPv6 addresses are only to be used inside a host and should never > be transmitted in real packets (including packets inside a tunnel) see section > 4.2 of RFC 4038 (even if informational). As other IESG reviewers, I wonder why > ::1/128 is not used? > > -- Section 8 -- > The document specifies no IANA actions while the shepherd write-up talks about > a IANA action. > > -- Section 9 -- > This section is only about IPv4 (TTL and RFC 1812). Please address IPv6 as well. > > > ---------------------------------------------------------------------- > COMMENT: > ---------------------------------------------------------------------- > > == COMMENTS == > > RFC 5881 (BFD) states that it applies to IPv4/IPv6 tunnels, may I infer that > this document is only required to address the Ethernet encapsulation ? I.e. > specifying the Ethernet MAC addresses? > > -- Section 3 -- > At first sight, I was surprized by having a BFD session per VXLAN VNI as it > will create some scalability issue, but, I assume that this is to detect > misconfiguration as well. If so, perhaps worth mentionnig the reasoning behind? > > In "the inner destination IP address SHOULD" it is unclear whether it is in the > all BFD packets, or only the request one or ... ? > > -- Section 4 -- > While probably defined in RFC7348, should "FCS" be renamed as "Outer Ethernet > FCS" for consistency with the "Outer Ethernet Header" in figure 2 ? > > Why not using the Source MAC address as the Destination MAC address ? This > would ensure that there is no conflict at the expense of "forcing" the > transmission of the frame even if addressed to itself. > > Please consider rewriting the section about TTL/Hop Limit as it is not easy to > parse/read. > > -- Section 9 -- > It is unclear to me (see also Ben's comment) what is the 'attack vector' of > sending packets with TTL=1 ? > > >
- Éric Vyncke's Discuss on draft-ietf-bfd-vxlan-09:… Éric Vyncke via Datatracker
- Re: Éric Vyncke's Discuss on draft-ietf-bfd-vxlan… Carlos Pignataro (cpignata)
- Re: Éric Vyncke's Discuss on draft-ietf-bfd-vxlan… Jeffrey Haas
- Re: Éric Vyncke's Discuss on draft-ietf-bfd-vxlan… Carlos Pignataro (cpignata)
- Re: Éric Vyncke's Discuss on draft-ietf-bfd-vxlan… Jeffrey Haas
- Re: Éric Vyncke's Discuss on draft-ietf-bfd-vxlan… Greg Mirsky
- Re: Éric Vyncke's Discuss on draft-ietf-bfd-vxlan… Carlos Pignataro (cpignata)
- Re: Éric Vyncke's Discuss on draft-ietf-bfd-vxlan… Greg Mirsky
- Re: Éric Vyncke's Discuss on draft-ietf-bfd-vxlan… Eric Vyncke (evyncke)
- Re: Éric Vyncke's Discuss on draft-ietf-bfd-vxlan… Eric Vyncke (evyncke)
- Re: Éric Vyncke's Discuss on draft-ietf-bfd-vxlan… Jeffrey Haas
- Re: Éric Vyncke's Discuss on draft-ietf-bfd-vxlan… Carlos Pignataro (cpignata)
- Re: Éric Vyncke's Discuss on draft-ietf-bfd-vxlan… Jeffrey Haas
- Re: Éric Vyncke's Discuss on draft-ietf-bfd-vxlan… Carlos Pignataro (cpignata)
- Re: Éric Vyncke's Discuss on draft-ietf-bfd-vxlan… Eric Vyncke (evyncke)