On Feb 15, 2012, at 1:56 AM, Bob Hinden wrote: > Martin, > > On Feb 14, 2012, at 2:45 PM, Martin Rex wrote: > >> Brian E Carpenter wrote: >>> >>> Martin, >>> >>>> One the one hand, the IETF was frowning upon NATs when they were >>>> developed outside of the IETF. But if you look at the IETFs >>>> (lack of) migration plan, the translation that you need in order >>>> to make old-IPv4 interoperate with new-IPv6, is actually worse than >>>> an IPv4 NAT. >>> >>> I'm sorry, but *any* coexistence between RFC791-IPv4-only hosts and >>> hosts that are numbered out of an address space greater than 32 bits >>> requires some form of address sharing, address mapping, and translation. >>> It doesn't matter what choice we made back in 1994. Once you get to the >>> point where you've run out of 32 bit addresses and not every node can >>> support >32 bit addresses, you have the problem. >> >> But what is your point? >> >> With a fully backwards compatible transparent addressing scheme, >> a much larger fraction of the nodes would have switched to actively >> use IPv6 many years ago. > > Right, just like they could have deployed dual stack many years ago too. > > The deployment problem was not due to technical issues, it was because the Internet changed to only deploy new technology that generated revenue in the short term. After a lot of thought, I have come to the conclusion that it wouldn't have mattered what the IETF did, we would still be facing the same problems. It wouldn't be seriously deployed until IPv4 address ran out. > > These "if we had only done foo" discussions all miss the biggest deployment factor. I disagree with that. With things that take considerable effort to develop and deploy, any sane business or agency would do a cost/benefit analysis, and not deploy unless they can see how it pays off. Smaller projects sometimes go under the radar. Maybe the cost-benefit analysis says it's not worth doing a cost-benefit analysis. When investment is low, people do things even without assurances that those would in fact be needed. I'll leave example from our employer out of this thread. If adding support for the next IP version in products was easy (say, 1-2 man-years for an OS, and 1-2 man months for an application), then Windows XP, Mac OS 10.1 and whatever Linux was running at the time and Solaris 2.9 would have had the support, and applications would follow quickly, long before IPv4 addresses became scarce. Yoav _______________________________________________ Ietf mailing list Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf