> This incompatible protocol break ... Incompatible protocol or is it time for the next IP version, without fragmentation right from the beginning ?
As the reasons, stated in the draft, also apply to IPv4. Would we think about deprecating the use of fragmentation fields in the IPv4 header and recommending they MUST always be set to 0 ? Kind regards, Marc Lampo On Thu, Jun 27, 2013 at 7:52 AM, Hagen Paul Pfeifer <ha...@jauu.net> wrote: > * Brian E Carpenter | 2013-06-27 13:14:12 [+1200]: > > >Cutting to the chase, and assuming that the next version > >will have more analysis and observational evidence, I'm thinking > >something like the following: > > Nearly, skip five words: "and the IPv6 fragment header". One more time: a > client of mine deploy sensor network applications using fragmentation. Not > just for fun, no because of 2460. Think about this: if this ID becomes an > RFC > (or even earlier) someone posts a patch removing fragmentation from > Linux/*BSD,3 month later all distribution ship a fragmentation/reassembly > less > stack. This breaks application, application which cannot changed because > they > are hard wired into silicon (DSP). This incompatible protocol break needs > more > time to mature out everywhere. > > I support the deprecation of fragmentation, but we need reassembling for a > transition period - not fragmentation. But this is not in contradiction > with > the current effort here - everybody can be happy. My recommendation > (slightly > changed version, see second sentence): > > 3. Recommendation > > This memo deprecates IPv6 fragmentation. Host SHOULD still be > able to > reassembly fragmented packets. Application and transport layer > protocols > SHOULD support effective PMTU discovery [RFC4821], since > ICMP-based PMTU > discovery [RFC1981] is unreliable. Any application or transport > layer > protocol that cannot support effective PMTU discovery MUST NOT in > any > circumstances send IPv6 packets that exceed the IPv6 minimum MTU > of 1280 > bytes. > > IPv6 stacks and forwarding nodes SHOULD continue to support inbound > fragmented IPv6 packets as specified in [RFC2460]. However, this > requirement exceeds the capability of some types of forwarding node > such as firewalls and load balancers. Therefore implementers and > operators need to be aware that on many paths through the Internet, > IPv6 fragmentation will fail. Legacy applications and transport layer > protocols that do not conform to the previous paragraph can expect > connectivity failures as a result. > > > > Hagen > -------------------------------------------------------------------- > IETF IPv6 working group mailing list > ipv6@ietf.org > Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 > -------------------------------------------------------------------- >
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