Bob, > -----Original Message----- > From: Bob Hinden [mailto:[email protected]] > Sent: Tuesday, September 03, 2019 5:08 PM > To: Templin (US), Fred L <[email protected]> > Cc: Bob Hinden <[email protected]>; Tom Herbert <[email protected]>; > [email protected]; IESG <[email protected]>; Joel > Halpern <[email protected]>; > [email protected]; [email protected] > Subject: Re: [Int-area] Alissa Cooper's No Objection on > draft-ietf-intarea-frag-fragile-16: (with COMMENT) > > Fred, > > > On Sep 3, 2019, at 2:10 PM, Templin (US), Fred L > > <[email protected]> wrote: > > > > Bob, > > > >> -----Original Message----- > >> From: Bob Hinden [mailto:[email protected]] > >> Sent: Tuesday, September 03, 2019 1:57 PM > >> To: Tom Herbert <[email protected]> > >> Cc: Bob Hinden <[email protected]>; Templin (US), Fred L > >> <[email protected]>; [email protected]; IESG > >> <[email protected]>; Joel Halpern <[email protected]>; > >> [email protected]; [email protected] > >> Subject: Re: [Int-area] Alissa Cooper's No Objection on > >> draft-ietf-intarea-frag-fragile-16: (with COMMENT) > >> > >> Tom, > >> > >>> On Sep 3, 2019, at 1:33 PM, Tom Herbert <[email protected]> wrote: > >>> > >>> Bob, > >>> > >>> I agree with Fred. Note, the very first line of the introduction: > >>> > >>> "Operational experience [Kent] [Huston] [RFC7872] reveals that IP > >>> fragmentation introduces fragility to Internet communication”. > >> > >> Yes, that text in in the first paragraph of the Introduction > >>> > >>> This attempts to frame fragmentation as being generally fragile with > >>> supporting references. However, there was much discussion on the list > >>> about operational experience that demonstrates fragmentation is not > >>> fragile. In particular, we know that fragmentation with tunnels is > >>> productively deployed and has been for quite some time. So that is the > >>> counter argument to the general statement that fragmentation is > >>> fragile. With the text about tunneling included in the introduction I > >>> believe that was sufficient balance of the arguments, but without the > >>> text the reader could be led to believe that fragmentation is fragile > >>> for everyone all the time which is simply not true and would be > >>> misleading. > >> > >> Yes, but we are discussing some text from the Introduction that to my read > >> didn’t say anything useful so I removed it. The > substantive > >> text about tunneling in in Section 3.5. The Introduction, is just the > >> introduction. The text was: > >> > >> This document acknowledges that in some cases, packets must be > >> fragmented within IP-in-IP tunnels [I-D.ietf-intarea-tunnels]. > >> Therefore, this document makes no additional recommendations > >> regarding IP-in-IP tunnels. > > > > Yes - good text that should be retained. > > > >> Why is that more useful than what is in 3.5? If it’s not making a > >> recommendation, why call this out in the introduction. There are lot > of > >> other things it doesn’t make recommendations about that aren’t in the > >> Introduction either. > > > > Because it sets a more appropriate tone and lets the reader know from the > > onset that > > fragmentation and encapsulation go hand in hand. And tunnel fragmentation > > avoids the > > issues raised by others in this thread. > > I don’t know how to evaluate “tone” in an IETF specification. > > How about if I move this text to section 5.3? I think that’s better than in > the Introduction. > > The section would be: > > 5.3. Packet-in-Packet Encapsulations > > This document acknowledges that in some cases, packets must be > fragmented within IP-in-IP tunnels. Therefore, this document makes no > additional recommendations regarding IP-in-IP tunnels. > > In this document, packet-in-packet encapsulations include IP-in-IP > [RFC2003], Generic Routing Encapsulation (GRE) [RFC2784], GRE-in-UDP > [RFC8086] and Generic Packet Tunneling in IPv6 [RFC2473]. [RFC4459] > describes fragmentation issues associated with all of the above- > mentioned encapsulations. > > The fragmentation strategy described for GRE in [RFC7588] has been > deployed for all of the above-mentioned encapsulations. This > strategy does not rely on IP fragmentation except in one corner case. > (see Section 3.3.2.2 of RFC 7588 and Section 7.1 of RFC 2473). > Section 3.3 of [RFC7676] further describes this corner case. > > See [I-D.ietf-intarea-tunnels] for further discussion.
Paragraph #1 beginning "This document acknowledges" looks good, but then why include paragraphs #2 and #3 since 'intarea-tunnels' is the place to discuss IP-in-IP encapsulation. So, why not shorten Section 5.3 and have it as simply: 5.3. Packet-in-Packet Encapsulations This document acknowledges that in some cases, packets must be fragmented within IP-in-IP tunnels. Therefore, this document makes no additional recommendations regarding IP-in-IP tunnels. See [I-D.ietf-intarea-tunnels] for further discussion. Fred > Bob > > > > > > Thanks - Fred > > > >> Bob > >> > >>> > >>> Speaking of balance, the introduction also mentions that: > >>> > >>> "this document recommends that upper-layer protocols address the > >>> problem of fragmentation at their layer" > >>> > >>> But the "problem" of fragmentation is in intermediate devices that > >>> don't properly handle it as the draft highlights. So it seems like > >>> part of addressing the problem should also be to fix the problem! That > >>> is implementations should be fixed to deal with fragmentation. IMO, > >>> this should be another high level recommendation that is mentioned in > >>> the introduction. > >> > >> I am serving as document editor. This to my understanding has been > >> through w.g. last call and now IESG review. > >>> > >>> Tom > >>> > >>> > >>> > >>> Tom > >>> > >>> > >>> > >>> > >>> > >>> On Tue, Sep 3, 2019 at 1:01 PM Bob Hinden <[email protected]> wrote: > >>>> > >>>> Fred, > >>>> > >>>>> On Sep 3, 2019, at 12:45 PM, Templin (US), Fred L > >>>>> <[email protected]> wrote: > >>>>> > >>>>> Bob, > >>>>> > >>>>>> -----Original Message----- > >>>>>> From: Bob Hinden [mailto:[email protected]] > >>>>>> Sent: Tuesday, September 03, 2019 9:10 AM > >>>>>> To: Templin (US), Fred L <[email protected]> > >>>>>> Cc: Bob Hinden <[email protected]>; Joe Touch > >>>>>> <[email protected]>; Alissa Cooper <[email protected]>; Joel > >> Halpern > >>>>>> <[email protected]>; [email protected]; > >>>>>> [email protected]; IESG <[email protected]>; intarea- > >>>>>> [email protected] > >>>>>> Subject: Re: [Int-area] Alissa Cooper's No Objection on > >>>>>> draft-ietf-intarea-frag-fragile-16: (with COMMENT) > >>>>>> > >>>>>> Fred, > >>>>>> > >>>>>>> On Sep 3, 2019, at 7:33 AM, Templin (US), Fred L > >>>>>>> <[email protected]> wrote: > >>>>>>> > >>>>>>> Why was this section taken out: > >>>>>>> > >>>>>>>> 1.1. IP-in-IP Tunnels > >>>>>>>> > >>>>>>>> This document acknowledges that in some cases, packets must be > >>>>>>>> fragmented within IP-in-IP tunnels [I-D.ietf-intarea-tunnels]. > >>>>>>>> Therefore, this document makes no additional recommendations > >>>>>>>> regarding IP-in-IP tunnels. > >>>>>> > >>>>>> This text in the Introduction was removed because, as noted in Warren > >>>>>> Kumari > >>>>>> Comment (2019-08-07 for -15), this didn’t need to be in the > >>>>>> introduction, and it didn’t say very much that isn’t described later > in > >> the > >>>>>> document. > >>>>>> > >>>>>> The normative text in Section 5.3. "Packet-in-Packet Encapsulations” > >>>>>> is unchanged. I think Section 5.3 covers the topic. It > >> includes the > >>>>>> reference to [I-D.ietf-intarea-tunnels]. > >>>>> > >>>>> While I agree that both passages supply a working vector to > >>>>> 'intarea-tunnels', > >>>>> the two strike very different tones. The former gives a balanced > >>>>> citation, while > >>>>> the latter calls it a "corner case" - twice! > >>>>> > >>>>> Whether we like it or not, fragmentation and encapsulation will > >>>>> continue to > >>>>> be associated with each other no matter what gets documented here. So, > >>>>> a respectful handoff to 'intarea-tunnels' would be appreciated. > >>>> > >>>> You are talking about text in the Introduction of the document. > >>>> > >>>> The important substance relating to tunnels is in Section 5.3. The > >>>> text is: > >>>> > >>>> 5.3. Packet-in-Packet Encapsulations > >>>> > >>>> In this document, packet-in-packet encapsulations include IP-in-IP > >>>> [RFC2003], Generic Routing Encapsulation (GRE) [RFC2784], GRE-in-UDP > >>>> [RFC8086] and Generic Packet Tunneling in IPv6 [RFC2473]. [RFC4459] > >>>> describes fragmentation issues associated with all of the above- > >>>> mentioned encapsulations. > >>>> > >>>> The fragmentation strategy described for GRE in [RFC7588] has been > >>>> deployed for all of the above-mentioned encapsulations. This > >>>> strategy does not rely on IP fragmentation except in one corner case. > >>>> (see Section 3.3.2.2 of RFC 7588 and Section 7.1 of RFC 2473). > >>>> Section 3.3 of [RFC7676] further describes this corner case. > >>>> > >>>> See [I-D.ietf-intarea-tunnels] for further discussion. > >>>> > >>>> Seems fine to me, in tone and substance. > >>>> > >>>> Bob > >>>> > >>>> > >>>>> > >>>>> Fred > >>>>> > >>>>>> Bob > >>>>>> > >>>>>> > >>>>>>> > >>>>>>> Tunnels always inflate the size of packets to the point that they may > >>>>>>> exceed > >>>>>>> the path MTU even if the original packet is no larger than the path > >>>>>>> MTU. And, > >>>>>>> for IPv6 the only guarantee is 1280. Therefore, in order to robustly > >>>>>>> support > >>>>>>> the minimum IPv6 MTU tunnels MUST employ fragmentation. > >>>>>>> > >>>>>>> Please put this section of text back in the document where it belongs. > >>>>>>> > >>>>>>> Thanks - Fred > >>>>>>> > >>>>>>>> -----Original Message----- > >>>>>>>> From: Int-area [mailto:[email protected]] On Behalf Of Joe > >>>>>>>> Touch > >>>>>>>> Sent: Tuesday, September 03, 2019 7:06 AM > >>>>>>>> To: Alissa Cooper <[email protected]> > >>>>>>>> Cc: Joel Halpern <[email protected]>; > >>>>>>>> [email protected]; [email protected]; The IESG > >>>>>> <[email protected]>; > >>>>>>>> [email protected] > >>>>>>>> Subject: Re: [Int-area] Alissa Cooper's No Objection on > >>>>>>>> draft-ietf-intarea-frag-fragile-16: (with COMMENT) > >>>>>>>> > >>>>>>>> Hi, all, > >>>>>>>> > >>>>>>>> So let me see if I understand: > >>>>>>>> > >>>>>>>> Alissa issues a comment. > >>>>>>>> > >>>>>>>> We discuss this on the list and come to a rare consensus on a way > >>>>>>>> forward. > >>>>>>>> > >>>>>>>> The new draft is issued that: > >>>>>>>> > >>>>>>>> a) ignores the list consensus > >>>>>>>> b) removes a paragraph not under the DISCUSS (1.1) > >>>>>>>> c) now refers to vague “other documents” without citation > >>>>>>>> d) most importantly: > >>>>>>>> > >>>>>>>> REMOVES a key recommendation that we MAY use frag where it works > >>>>>>>> > >>>>>>>> Asserts the false claim that IP fragmentation “will fail” in the > >>>>>>>> Internet, > >>>>>>>> despite citing evidence that the *majority of the time* it does work > >>>>>>>> e.g., for IPv6, sec 3.9 > >>>>>>>> > >>>>>>>> What happened? Why is a change this substantial not reflecting the > >>>>>>>> *list consensus*? > >>>>>>>> > >>>>>>>> Joe > >>>>>>>> > >>>>>>>>> On Sep 3, 2019, at 5:59 AM, Alissa Cooper via Datatracker > >>>>>>>>> <[email protected]> wrote: > >>>>>>>>> > >>>>>>>>> Alissa Cooper has entered the following ballot position for > >>>>>>>>> draft-ietf-intarea-frag-fragile-16: No Objection > >>>>>>>>> > >>>>>>>>> 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-intarea-frag-fragile/ > >>>>>>>>> > >>>>>>>>> > >>>>>>>>> > >>>>>>>>> ---------------------------------------------------------------------- > >>>>>>>>> COMMENT: > >>>>>>>>> ---------------------------------------------------------------------- > >>>>>>>>> > >>>>>>>>> Thanks for addressing my DISCUSS. > >>>>>>>>> > >>>>>>>>> > >>>>>>>>> _______________________________________________ > >>>>>>>>> Int-area mailing list > >>>>>>>>> [email protected] > >>>>>>>>> https://www.ietf.org/mailman/listinfo/int-area > >>>>>>>> > >>>>>>>> _______________________________________________ > >>>>>>>> Int-area mailing list > >>>>>>>> [email protected] > >>>>>>>> https://www.ietf.org/mailman/listinfo/int-area > >>>>> > >>>> > >>>> _______________________________________________ > >>>> Int-area mailing list > >>>> [email protected] > >>>> https://www.ietf.org/mailman/listinfo/int-area > > _______________________________________________ Int-area mailing list [email protected] https://www.ietf.org/mailman/listinfo/int-area
