On 29/06/2013 09:03, Templin, Fred L wrote: > Hi Brian, > >> Let's face it, this train left the station a while back. (This doesn't >> mean I'm happy, but it is what it is.) > > Do you mean that you want to give up and declare that the fixed > MTU for IPv6 is 1280 now and for always (and remember, that still > would not excuse tunnels from using frag/reass)?
No. I believe that (a) strongly recommending packetizatiion layer PMTUD and deprecating fragmentation at source is a sound long term policy and (b) accepting that strapping the MTU at 1280 is a reasonable short term policy. If (a) progressively pervades the installed base then (b) can be dropped as the years go by. (Though frankly I have never seen MTU problems in v6 since I stopped trying to use 6to4; I've used three different configured tunnel solutions, and various native services, without problems. So while there are clearly paths with this problem, I suspect they're a minority even today.) > I still think the situation can be salvaged with something like SEAL, > but if we want to just give up then I think I agree with others that > we may need to increment the IP protocol version (I for one would not > like to see that). In effect using SEAL is part of (a), for the cases where tunels are used, isn't it? Talk of changing the version number doesn't have much to do with the world that I live in. We have plenty of experience now of how easy it isn't to change the version number. Brian -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------