Fernando, RFC7872 seems to document the state of the Internet at a given point of time. I do not know if things have gotten better or worse for extension headers in the Internet since that time, but I believe that support for extension headers in the Internet must become more robust. Fragmentation is one reason. Another is the proposed MTU extension header, and there are still others. Let's not ossify the IPv6 Internet yet the way the IPv4 Internet is ossified.
Fred > -----Original Message----- > From: Fernando Gont [mailto:[email protected]] > Sent: Tuesday, September 03, 2019 8:57 AM > To: Templin (US), Fred L <[email protected]>; Joe Touch > <[email protected]>; 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) > > On 3/9/19 18:41, Templin (US), Fred L wrote: > > > > > >> -----Original Message----- > >> From: Fernando Gont [mailto:[email protected]] > >> Sent: Tuesday, September 03, 2019 7:50 AM > >> To: Templin (US), Fred L <[email protected]>; Joe Touch > >> <[email protected]>; 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) > >> > >> On 3/9/19 17:33, Templin (US), Fred L 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. > >>> > >>> 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. > >> > >> Isn't that an oxymoron? If fragmentation is fragile, if you need > >> something robust, you need to rely on something else.... > > > > IPv6 fragmentation is not fragile - only IPv4 fragmentation is fragile. > > * RFC7872. > * https://blog.apnic.net/2017/08/22/dealing-ipv6-fragmentation-dns/ > > These seems pretty fragile to me. YMMV, though. > > Thanks, > -- > Fernando Gont > SI6 Networks > e-mail: [email protected] > PGP Fingerprint: 6666 31C6 D484 63B2 8FB1 E3C4 AE25 0D55 1D4E 7492 > > > _______________________________________________ Int-area mailing list [email protected] https://www.ietf.org/mailman/listinfo/int-area
