On 18/02/2017 07:00, Stewart Bryant wrote: > Ole > > Are you saying: > > A correct implementation of RFC2460 MUST NOT insert an EH at any point > along the path other than at the packet source. > > Or > > A correct implementation of RFC2460 MAY insert an EH at any point along > the path. Ole doesn't, apparently, want to say either of those things. I want to say the first *as part of the promotion to Internet Standard* because it was the clear and documented intent of the authors and WG of RFC 1883, which became RFC 2460. (Documented in the ancient email I dug out a while back.) And it has been assumed by subsequent work such as PMTUD and IPsec/AH. If we want to *change* it, that's a separate discussion from promoting the current standard. We can do it afterwards. (And in answer to some other comments, I'll note that RFC 791 does not forbid NAT, but I bet the authors would have done so if they'd thought of it. When did forbidding something in an RFC ever prevent people from implementing it in a limited domain?) Brian