from what we have exchanged, the only things we do not agree with each other are: - you do not believe IPv4/v6 mixed environment would work, or too tough to make it work that it is not justifiable. also you see some problem in nodes with multiple addresses. - i do believe it would work ok > > if you are not under NDA, could you please be more specific? source > > code, RFC/draft for the protocol, whatever? i'm getting tired of this > > guessing games. > > > what do you want me to do, describe in detail every distributed > application that I've ever worked with? I'm not talking about any > specific application, I'm generalizing from several applications that > I've worked with and/or am otherwise familiar with. when you generalize things you might have missed some of the details, so if you could please send me pointers to details (privately). > > once you run ALG (which i guess you do not like) IPv6-to-IPv4 or IPv4-to- > > IPv6 looks much like SMTP relaying. > true. ALGs are okay for applications that have explicit intermediaries, > like SMTP. I don't like ALGs so much when they're used as interception > proxies. sometimes they work okay, sometimes not. yup. > > do not underestimate my paranoid-ness, i'm an OpenBSD developer > somehow, I think this should be on a t-shirt, or a bumper sticker. :) heh, maybe. > agree with all of those. but it sounds like you're close to arguing > that because there are so many other things that can screw with DNS, > it's okay for getaddrinfo() to return bogus results too. i did not say that. what i was trying to say are below: - you said that you do not trust getaddrinfo/getnameinfo but you seem to trust other DNS functions/responses. - under what kind of condition would you trust DNS, and would you not? - are you sure it is ok when you trust it? > > ok, so you are basically worried about uRPF, performance difference, > > and/or firewalling policy differences when you have multiple exit links. > > > it's not just multiple exit links, it's having multiple addresses per > host for any number of reasons. (mobility, renumbering, the desire to > have stable local addresses, and also the possibility of multiple active > network interfaces) note that "client machines with multiple IP address" has been a common practice even for IPv4, more than 15 years at least. i had the first laptop when i was in university, i ran 386BSD (4.4BSD) so that makes it around 15 years ago. mobility - i do not see your problem, maybe mobile-ip6 guys would want to speak up renumbering - multiple address DO help stable local address - well, define "stable" multiple active network interfaces - it is a common practice, use MacOS X machines with wireless and ethernet and switch them over time. TCP connection would not survive, which is a problem, but other than that, things are seamless (like browsers). > > do not take it as a self-promotion, but my take on this is in RFC3178. > > > but things like RFC 3178 do help. if we can get back to the expectation > that one address per host is the normal case, we'll make life much > simpler for application writers. the thing is, application writers does not really need to choose addresses to be used, as long as you write a program/protocol spec so that it does not embed IPv4/v6 addresses or DNS names. if you embed it, you would want to use DNS names instead of IPv4/v6 addresses, as you will want your application to work ok with the next protocol that would be introduced after IPv6. i would not call it IPv8 :-P > > so i can solve problem for Skype, so i guess i can solve problem for > > your "distributed computation system". want to hire a consultant? :-P > > > I can solve it too, and have done so on a couple of occasions. but I > don't pretend that it's easy to retro-fit every existing distributed > application (or to build every new distributed application) to handle > multiple realms. NATs have drastically raised the burden on > applications by dividing the Internet up into multiple address realms; > similarly, IPv4/IPv6 coexistence also divides the Internet up into > multiple address realms. Thus a "mixed" IPv4/IPv6 network is almost as > dysfunctional as a NATted IPv4 network. ok, i can understand your concern, but we need to do it anyways. unlike the introduction of IPv4, you cannot set a flag day, can you? itojun _______________________________________________ Ietf@xxxxxxxx https://www1.ietf.org/mailman/listinfo/ietf