On Jun 15, 2012, at 11:50 PM, Masataka Ohta wrote: > Joe Touch wrote: > >> Again, this document doesn't change the current situation. Operators who >> clear the DF bit are not innocent - they need to override a default >> setting. They are active participants. They ARE guilty of violating >> existing standards. > > While IETF is not a protocol police and clearing DF is not > considered guilty by operators community, the following > draft: > > draft-generic-v6ops-tunmtu-03.txt > > to fragment IPv6 packets by intermediate routers should be > very interesting to you. It is aware of our IPv4-ID doc, and consistent with it. When the DF is "ignored", the ID field is rewritten - i.e., turning the packet from atomic to compliant non-atomic within the tunnel. This is consistent with the notion that the ID field must be unique, and that atomic packets need not have unique IDs. The rewriting is hidden - happens only inside the tunnel, is controlled uniquely by the source, and does not need coordination by other sources. Joe