Hi, > -----Original Message----- > From: ipv6-boun...@ietf.org [mailto:ipv6-boun...@ietf.org] On Behalf Of > Usman Latif > Sent: Tuesday, June 25, 2013 6:07 PM > To: ipv6@ietf.org > Subject: RE: New Version Notification for draft-bonica-6man-frag- > deprecate-00.txt > > I have the following suggestion: > > IPv6 hosts can try to gain knowledge of the path MTU to a destination.
That is called RFC4821. > If the path blocks or filters PMTUD etc, then the host should revert to > 1280 bytes else the hosts can use a higher packet size. With RFC4821, hosts can use larger packet sizes (if they are available) even it PMTUD doesn't work. > This mechanism would make Fragment header redundant anyway There have been a number of reasons identified as to why the IPv6 fragment header is still needed. > The only implication of the above mechanism would be that network > providers 'must' support 1280 byte IPv6 packets in all situations That goes without saying. The IPv6 minMTU is 1280 - it's the law. Thanks - Fred fred.l.temp...@boeing.com > Regards, > Usman > > > On 25/06/2013, at 5:00 AM, ipv6-requ...@ietf.org wrote: > > > If you have received this digest without all the individual message > > attachments you will need to update your digest options in your list > > subscription. To do so, go to > > > > https://www.ietf.org/mailman/listinfo/ipv6 > > > > Click the 'Unsubscribe or edit options' button, log in, and set "Get > > MIME or Plain Text Digests?" to MIME. You can set this option > > globally for all the list digests you receive at this point. > > > > > > > > Send ipv6 mailing list submissions to > > ipv6@ietf.org > > > > To subscribe or unsubscribe via the World Wide Web, visit > > https://www.ietf.org/mailman/listinfo/ipv6 > > or, via email, send a message with subject or body 'help' to > > ipv6-requ...@ietf.org > > > > You can reach the person managing the list at > > ipv6-ow...@ietf.org > > > > When replying, please edit your Subject line so it is more specific > > than "Re: Contents of ipv6 digest..." > > > > > > Today's Topics: > > > > 1. RE: New Version Notification for > > draft-bonica-6man-frag-deprecate-00.txt (Ronald Bonica) > > 2. Re: New Version Notification for > > draft-bonica-6man-frag-deprecate-00.txt (Fred Baker (fred)) > > 3. Re: New Version Notification for > > draft-bonica-6man-frag-deprecate-00.txt (Ole Troan) > > 4. RE: New Version Notification for > > draft-bonica-6man-frag-deprecate-00.txt (Templin, Fred L) > > > > > > --------------------------------------------------------------------- > - > > > > Message: 1 > > Date: Mon, 24 Jun 2013 16:38:06 +0000 > > From: Ronald Bonica <rbon...@juniper.net> > > To: George Michaelson <g...@algebras.org>, "ipv6@ietf.org 6man-wg" > > <ipv6@ietf.org> > > Subject: RE: New Version Notification for > > draft-bonica-6man-frag-deprecate-00.txt > > Message-ID: > > > <2cf4cb03e2aa464ba0982ec92a02ce2509f87...@by2prd0512mb653.namprd05.prod > .outlook.com> > > > > Content-Type: text/plain; charset="us-ascii" > > > > > > I'd like to understand the basis of these assertions. I believe what > I am seeing, on the edge, suggests there is in fact V6 fragmentation in > both TCP and UDP. > > > > > > Hi George, > > > > It would be helpful if you could describe: > > > > > > - Where your observations are being made > > > > - What percentage of traffic is fragmented > > > > - What kinds of packets are being fragmented > > Ron > > > > -------------- next part -------------- > > An HTML attachment was scrubbed... > > URL: <http://www.ietf.org/mail- > archive/web/ipv6/attachments/20130624/2d588547/attachment.htm> > > > > ------------------------------ > > > > Message: 2 > > Date: Mon, 24 Jun 2013 16:50:04 +0000 > > From: "Fred Baker (fred)" <f...@cisco.com> > > To: Tore Anderson <t...@fud.no> > > Cc: "ipv6@ietf.org 6man-wg" <ipv6@ietf.org> > > Subject: Re: New Version Notification for > > draft-bonica-6man-frag-deprecate-00.txt > > Message-ID: > > <8c48b86a895913448548e6d15da7553b924...@xmb-rcd-x09.cisco.com> > > Content-Type: text/plain; charset="iso-8859-1" > > > > > > On Jun 24, 2013, at 12:45 AM, Tore Anderson <t...@fud.no> wrote: > > > >> * Fred Baker (fred) > >> > >>> On Jun 22, 2013, at 2:29 AM, Tore Anderson <t...@fud.no> wrote: > >>>> - When a SIIT translator receives an IPv4 packet with DF=0 that > >>>> would result in an IPv6 packet that would exceed the IPv6 link > MTU, > >>>> it will split the original packet into IPv6 fragments. > >>> > >>> It *could* fragment the IPv4 packet and send it in two unfragmented > >>> IPv6 packets. > >> > >> Wouldn't doing IPv4 fragmentation before translation to IPv6 be > >> logically identical to this other case I mentioned? > > > > Ah. You're correct. I was thinking about tunnels. > > > >>>> - When a SIIT translator receives an IPv4 fragment, it will > translate > >>>> this into one or more IPv6 fragments. > >> > >> I can't see how simply omitting the Fragmentation header in the IPv6 > >> output could work here, as the node receiving those two unfragmented > >> IPv6 packets would see the first one containing a truncated L4 > payload, > >> while the second one would be just garbage as it doesn't include a > L4 > >> header. > >> > >> Tore > > > > ----------------------------------- > > "We are learning to do a great many clever things...The next great > task > > will be to learn not to do them." > > > > - G. K. Chesterton (1874-1936) > > > > > > > > > > > > > > ------------------------------ > > > > Message: 3 > > Date: Mon, 24 Jun 2013 13:37:41 -0400 > > From: Ole Troan <otr...@employees.org> > > To: Sheng Jiang <jiangsh...@huawei.com> > > Cc: "ipv6@ietf.org 6man-wg" <ipv6@ietf.org>, "Fred Baker \(fred\)" > > <f...@cisco.com> > > Subject: Re: New Version Notification for > > draft-bonica-6man-frag-deprecate-00.txt > > Message-ID: <34e0f96d-5ccb-4275-af64-e451b0036...@employees.org> > > Content-Type: text/plain; charset=us-ascii > > > >>> I suppose I'm the contrarian > >> > >> +1. For me, this draft looks dangerous by proposing to deprecate > fragmentation with only one-side observation. This draft does not give > enough analysis on these existing fragmentation use cases, particularly > these use cases the fragments within a single domain. > >> > >> On other side , only disallowing fragmentation to be used among > domains may helpful to reduce the operational complex. > > > > this draft should help us tease out answers to the question: > > "if we wanted to deprecate IPv6 fragmentation, could we?" > > > > then when we know the collateral damage, it will be easier to answer > the other question: > > "should we deprecate IP layer fragmentation or not". > > > > cheers, > > Ole > > > > ------------------------------ > > > > Message: 4 > > Date: Mon, 24 Jun 2013 17:50:36 +0000 > > From: "Templin, Fred L" <fred.l.temp...@boeing.com> > > To: "Fred Baker (fred)" <f...@cisco.com>, Tore Anderson <t...@fud.no> > > Cc: "ipv6@ietf.org 6man-wg" <ipv6@ietf.org> > > Subject: RE: New Version Notification for > > draft-bonica-6man-frag-deprecate-00.txt > > Message-ID: > > <2134F8430051B64F815C691A62D983180A93A6@XCH-BLV- > 504.nw.nos.boeing.com> > > Content-Type: text/plain; charset="us-ascii" > > > > Hi Fred, > > > >> -----Original Message----- > >> From: ipv6-boun...@ietf.org [mailto:ipv6-boun...@ietf.org] On Behalf > Of > >> Fred Baker (fred) > >> Sent: Sunday, June 23, 2013 4:12 PM > >> To: Tore Anderson > >> Cc: ipv6@ietf.org 6man-wg > >> Subject: Re: New Version Notification for draft-bonica-6man-frag- > >> deprecate-00.txt > >> > >> > >> On Jun 22, 2013, at 2:29 AM, Tore Anderson <t...@fud.no> wrote: > >>> - When a SIIT translator receives an IPv4 packet with DF=0 that > would > >>> result in an IPv6 packet that would exceed the IPv6 link MTU, it > will > >>> split the original packet into IPv6 fragments. > >> > >> It *could* fragment the IPv4 packet and send it in two unfragmented > >> IPv6 packets. > >> > >>> I cannot support your draft until it discusses or provides > solutions > >> for > >>> the above considerations. > >> > >> I'm in a similar case with respect to protocols above IPv6 (OSPF and > >> NFS/UDP come quickly to mind) that depend on fragmentation to deal > with > >> the issue. I think the Robustness Principle tells us that such > >> applications SHOULD figure out how to live with PMTU, but it also > tells > >> us that we can't deprecate fragmentation unless all known instances > >> that depend on it have defined practical work-arounds. I suspect > that > >> this would imply the re-creation of the fragmentation feature in an > >> intermediate protocol, > > > > That is essentially what SEAL does - it provides an intermediate- > level > > segmentation and reassembly capability that avoids the pitfalls of IP > > fragmentation. > > > >> which seems like a lot of work with little real gain. > > > > It's not that bad, and IMHO worth it. > > > > Thanks - Fred > > fred.l.temp...@boeing.com > > > >> -------------------------------------------------------------------- > >> IETF IPv6 working group mailing list > >> ipv6@ietf.org > >> Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 > >> -------------------------------------------------------------------- > > > > > > ------------------------------ > > > > _______________________________________________ > > ipv6 mailing list > > ipv6@ietf.org > > https://www.ietf.org/mailman/listinfo/ipv6 > > > > > > End of ipv6 Digest, Vol 110, Issue 75 > > ************************************* > -------------------------------------------------------------------- > IETF IPv6 working group mailing list > ipv6@ietf.org > Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 > -------------------------------------------------------------------- -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
