Well, there’s the tautology that “it worked when it worked”. Given that’s basically the rule that defines *everything* in the Internet, it’s baffling we need to say it again here, but if we did, we could simply state:
“The Internet is a best-effort system and lacks a formal validation or conformance mechanism. Like any other protocol feature, IP fragmentation is useful only when it actually works - both by successfully traversing routers and other in-network devices and when it is correctly supported by endpoints. As a consequence, like any other protocol feature, IP fragmentation MAY be used by new protocols that validate its successful traversal and provide an alternate as a backup.” (and yes, if we’re going to try to imply that frag is limited, it really should be clear that this is *no different than any other protocol feature* in the Internet) Joe > On Aug 15, 2019, at 6:59 AM, Ron Bonica > <[email protected]> wrote: > > Folks, > > Has anyone proposed text that: > > a) satisfies Alissa's request > b) satisfies the WG > > If not, do we believe that such text could possibly exist? > > Ron > > > > > Juniper Business Use Only > > -----Original Message----- > From: Brian E Carpenter <[email protected]> > Sent: Tuesday, August 6, 2019 8:55 PM > To: Alissa Cooper <[email protected]>; Tom Herbert <[email protected]> > Cc: Joel Halpern <[email protected]>; > [email protected]; int-area <[email protected]>; IESG > <[email protected]>; intarea-chairs <[email protected]> > Subject: Re: [Int-area] Alissa Cooper's Discuss on > draft-ietf-intarea-frag-fragile-15: (with DISCUSS and COMMENT) > > On 07-Aug-19 12:11, Alissa Cooper wrote: >> Hi Tom, >> >>> On Aug 6, 2019, at 5:41 PM, Tom Herbert <[email protected]> wrote: >>> >>> On Tue, Aug 6, 2019 at 1:30 PM Alissa Cooper via Datatracker >>> <[email protected]> wrote: >>>> >>>> Alissa Cooper has entered the following ballot position for >>>> draft-ietf-intarea-frag-fragile-15: 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://urldefense.proofpoint.com/v2/url?u=https-3A__www.ietf.org_ie >>>> sg_statement_discuss-2Dcriteria.html&d=DwIFaQ&c=HAkYuh63rsuhr6Scbfh0 >>>> UjBXeMK-ndb3voDTXcWzoCI&r=Fch9FQ82sir-BoLx84hKuKwl-AWF2EfpHcAwrDThKP >>>> 8&m=IUZsPOprgYi_5nBSPGeqNCLb8LwDMKCxRNeEBfcUZ5c&s=c7tAk-Lfr6pcQSMn1x >>>> 1tdfjkQsL8F_NryIiq3caZ26k&e= for more information about IESG DISCUSS >>>> and COMMENT positions. >>>> >>>> >>>> The document, along with other ballot positions, can be found here: >>>> https://urldefense.proofpoint.com/v2/url?u=https-3A__datatracker.iet >>>> f.org_doc_draft-2Dietf-2Dintarea-2Dfrag-2Dfragile_&d=DwIFaQ&c=HAkYuh >>>> 63rsuhr6Scbfh0UjBXeMK-ndb3voDTXcWzoCI&r=Fch9FQ82sir-BoLx84hKuKwl-AWF >>>> 2EfpHcAwrDThKP8&m=IUZsPOprgYi_5nBSPGeqNCLb8LwDMKCxRNeEBfcUZ5c&s=lb6u >>>> 0SVhJIFnTV7TdqeLiDBfadRxJkAxNEDqOvFqhyQ&e= >>>> >>>> >>>> >>>> -------------------------------------------------------------------- >>>> -- >>>> DISCUSS: >>>> -------------------------------------------------------------------- >>>> -- >>>> >>>> Thanks for writing this document. >>>> >>>> Section 6.1 says: >>>> >>>> "Developers MAY develop new protocols or applications that rely on IP >>>> fragmentation if the protocol or application is to be run only in >>>> environments where IP fragmentation is known to be supported." >>>> >>>> I'm wondering if there should be a bit more nuance here to make the >>>> recommendation clearer. Do we think there is a case where an >>>> application protocol developed in the IETF will be known to only run >>>> in environments where fragmentation is supported? If we don't think >>>> developing such a protocol would be in scope for the IETF, then I'm >>>> wondering if that case should be called out explicitly with a stronger >>>> normative requirement. >>>> >>> Alissa, >>> >>> Are you distinguishing between protocol development and application >>> development? >> >> I’m specifically wondering about application protocols (as distinct from >> other protocols) developed in the IETF (as distinct from developed >> elsewhere). Sometimes we use BCPs to guide future work in the IETF >> specifically, and it seemed to me that in that specific slice — >> IETF-developed application protocols — we may be able to make a stronger >> recommendation since we can’t be sure of the environment in which any given >> application protocol would be deployed (I think, but would be open to >> arguments otherwise). > > fwiw, I agree with what I think Alissa is saying. Unless we actually > *implement* a mechanism to define and support limited domains > (draft-carpenter-limited-domains) protocol designers cannot safely make > assumptions such as "fragmentation works". > > Maybe this paragraph needs to be more of a health warning than a somewhat > dubious RFC2119 statement. At least, "should not ... unless" might be a > better formulation than "MAY ... if". > > Brian > _______________________________________________ > 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
