On Jun 1, 2013, at 12:35 AM, Brian E Carpenter <brian.e.carpenter@xxxxxxxxx> wrote: > On 01/06/2013 15:00, John C Klensin wrote: >> >> --On Friday, May 31, 2013 17:23 -0700 Randy Bush <randy@xxxxxxx> >> wrote: >> >>> < rant > >>> >>> the sad fact is that the ietf culture is often not very good at >>> listening to the (ops) customer. look at the cf we have made >>> out of ipv6. the end user, and the op, want the absolute >>> minimal change and cost, let me get an ipv6 allocation from >>> the integer rental monopoly, flip a switch or two, and get 96 >>> more bits no magic. 15 years later, dhcp is still a cf, i >>> have to run a second server (why the hell does isc not merge >>> them?), i can not use it for finding my gateway or vrrp exit, >>> ... at least we got rid of the tla/nla classful insanity. but >>> u/g? puhleeze. >> >> Randy, >> >> I suggest that characterizing that set of issues as IETF versus >> Ops is probably not completely right either. > It was more complicated. I was actually running a team that ran site > network ops at the time, and (since DHCP was not yet deployable), > IPv4 was then a serious nuisance to manage, compared say to Novell > Netware and, even, Appletalk. There were good reasons we wanted > stateless auto-configuration and unlimited subnet size, to mention > two IPv6 bells and whistles. If DHCP had already been deployed, > our opinion might have been different. > Yes, it was more complicated, but the sad part is that DHCP was widely deployed in V4 long before V6 was a viable transport for real work on the Internet. Operators kept asking for DHCP and kept being slapped down by zealots who refused to listen to / consider why the Ops were asking for this. I *really* want to make sure that my CEO always gets the same address, and want him to be assigned specific DNS servers and use a certain gateway. The folk who manage the DHCP are the "Internal Services Infrastructure Group" (aka "The windows monkeys") and I'm sure as heck not giving them access to my router to twiddle knobs on it. >> For example, with >> IPv6, the IETF has proposed multiple transition solutions with >> no roadmap as to which one to apply under what circumstances and >> growing evidence that some of those solutions are unworkable in >> practice and others are incompatible with what are claimed to be >> fundamental and important features of the Internet. > > It turns out that as soon as you envisage a network in which some > nodes only support 32 bit addresses and other nodes can't get > a globally unique 32 bit address, you are forced into a world > of hurt that requires some combination of NAT, tunnels and > dual-stack. That is completely independent of the design of > IPng, and we knew it 1994. > Yes, hindsight always makes things *much* clearer. It also provides a nice sandbox to stand on…. Anyway, I think that going down the path of "There are warts in V6, I want a refund!" is not helpful. What I hope we can try and focus on is how we can improve understanding of what the customer (operators, users) actually wants, how and where the protocols of the future will be used, how we can incorporate changes as we get feedback and understand new requirements, etc. I was not intending to point fingers (although I realize I did), but rather to try show places where the protocol could have improved with a better understanding of what folk were looking for / with more operator input... > So while your criticism is valid that we collectively came up > with too many such combinations, that collective mistake was > (IMHO) not a result of the design of IPv6 as such. It was more > caused by the design of human beings. I'd go further -- some of the issue is (IMO) caused by the consensus driven nature of how we do things. We all have different sets of interests and different priorities. Because of a need to achieve consensus, we end in something kind of like horse-trading. We add features to appease some set of folk, and compromise on other bits to appease others. I suspect that if one or two folk had designed this, soup-to-nuts, we'd have ended up with something cleaner. > >> It doesn't >> take a skilled operations person to understand that is a >> problem; someone with a pointy head and barely enough clue to >> figure out what a "bit" is much less how many of them are in >> various addresses can derive a "don't be the first person on the >> block" or "don't migrate if you can figure out an alternative" >> lesson from that. >> >> Similarly, various applications folks within the IETF have >> pointed out repeatedly that any approach that assigns multiple >> addresses, associated with different networks and different >> policies and properties, either requires the applications to >> understand those policies, properties, and associated routing >> (and blows up all of the historical application-layer APIs in >> the process) or requires request/response negotiation that TCP >> doesn't allow for (and blows up most of the historical >> application-layer APIs). > > It's true, but to avoid that, I think we'd have to abolish > cellular telecommunications, Wi-Fi, and competition between > providers. Not sure I agree. Most apps on my iPhone seem to work just fine while I wander in and out of my house and move from WiFi to cellular. As for competition between providers -- folk have been doing this with e.g BGP for years. Most CPE lets you easily swap between providers (by moving a wire :-)) and some let you share multiple by NATing (yes, I know, I know) some sessions to one and others to the other provider... > >> One of the original promises about >> IPv6 was no need for changes to TCP and consequent transparency >> to most applications. Ha! > > Right, but again - only part of that is due to the change of > address size and socket API details. Most of it is due to > multiple connectivity. That was going to happen anyway. > >> >> I have never been convinced that "longer addresses and nothing >> else" was the only viable solution for IPng, > > Don't forget, BTW, that even "just" changing address size > from 32 to 64 would have blown up almost every app written to > BSD sockets (since Real Programmers Don't Use Structures and > almost everybody used to stick addresses into uint_32). > There never was a free lunch on the table. Yes, IP is fundamental plumbing, and folk make assumptions about how the plumbing works / take shortcuts. Changing fundamental plumbing is hard, and requires changes to all the fittings, valves, etc. W > > Brian > >> but I don't think >> it requires an advanced degree in economics to understand that, >> if the incentives to do something don't exceed the costs and >> risks of doing it, one shouldn't expect a lot of rational folks >> to charge off and do it. A complex system with high deployment >> costs and risks and a dubious set of advantages is not a story >> that is going to sell itself. And, again, it doesn't require a >> sophisticated operator to figure that out. >> >> None of this takes away from your rant (or Warren's). But I >> suggest that, on several of the dimensions you identify, the >> operators are not being singled out for abusive treatment >> because we don't listen to each other or elementary >> decision-making or economic realities either... at least where >> broad issues, rather than fine-tuning of a spec are concerned. >> >> john >> >> >> >> > -- There were such things as dwarf gods. Dwarfs were not a naturally religious species, but in a world where pit props could crack without warning and pockets of fire damp could suddenly explode they'd seen the need for gods as the sort of supernatural equivalent of a hard hat. Besides, when you hit your thumb with an eight-pound hammer it's nice to be able to blaspheme. It takes a very special and straong-minded kind of atheist to jump up and down with their hand clasped under their other armpit and shout, "Oh, random-fluctuations-in-the-space-time-continuum!" or "Aaargh, primitive-and-outmoded-concept on a crutch!" -- Terry Pratchett