James, > -----Original Message----- > From: james woodyatt [mailto:[EMAIL PROTECTED] > Sent: Wednesday, December 05, 2007 3:27 PM > To: IETF IPv6 Mailing List > Subject: Re: Stupid ULA discussion > > The subject line on this thread is absolutely correct. > > On Dec 5, 2007, at 13:32, Brian Dickson wrote: > > Iljitsch van Beijnum wrote: > >> ULA is LOCAL. > >> > >> It has nothing to do with PI. > >> > >> People need address space to number the links between their SQL > >> and web servers. This is completely orthogonal to address space > >> used on the internet. > > > > ULA is also UNIQUE. > > (Well, for half of ULA, "probably unique"). > > The phrase you are looking for is "statistically unique." > > "Probably," my house will still be standing in another thirty > years. > Yet, I'm still paying for fire insurance. "Statistically," there is > no chance I'm going to die by being struck on the head directly by a > newly fallen meteorite. Am I concerned enough about my exposure to > the risk of falling meteorites to worry about whether my life > insurance policy covers it? Not at all. > > Which gives me an idea: I should go into the insurance business, > selling ULA prefixes that I *GUARANTEE* (for an UNLIMITED > TIME!!!) to > be ABSOLUTELY UNIQUE or I will pay triple the cost of migrating your > network to a new ULA prefix when a documented collision occurs. I > can do this with 5 lines of totally stateless Perl added to some > stupid web server- it's just a random number generator. I'll MAKE > ZILLIONS FAST!
I have seen phony versions of such a "service" advertised by others at least twice in the past; nice work if you can get it! > > It would be a service, rather than a disservice, to the community > > of "network admins" (LAN admins), to educate them on the value of > > uniqueness. > > And the difference between "probably unique" and *statistically* > unique. Here's Brad DeLong explaining what kinds of tragedy can > befall the poor sod who fails to grasp the importance of statistics: > > <http://delong.typepad.com/sdj/2007/12/intellectual-ga.html> > > The key sentences... > >> This is the principal insight of the science of statistics. it is > >> an important insight. It is a powerful insight. It is also not an > >> *obvious* insight--that's what makes it powerful and important. > >> > > Emphasis mine. > > > And to point out the existence of a suitable replacement > for IPv4's > > 10.0.0.0/8 et al, if they want a non-registered, non-unique, truly > > non-routable address space that maps well to their current RFC > > 1918 space. > > > > And that would be the IPv4-mapped IPv6 address space for RFC 1918. > > I.e. ::ffff:10.0.0.0, ::ffff:172.16.0.0 and > ::ffff:192.168.0.0 (as / > > 104, /108, and /112 respectively.) > > > > And yes, I know it's ugly and rude. > > Suresh Krishnan is correct. Please do not suggest anything remotely > close to this. Not V4MAPPED addresses. Not V4COMPAT > addresses. Not > 6to4-prefix addresses. Not Teredo addresses. Please do not embed > RFC 1918 addresses in IPv6 addresses full-stop. This is exactly why we have ISATAP addresses (RFC4214). Fred [EMAIL PROTECTED] > To do so is morally > equivalent to reinventing the functionality of the deprecated site- > local addresses in some other corner of the address space for > no good > purpose. That way lies utter madness. Go not that way. > > > But it makes it easy for the end admin to manage the dual-stack > > universe between their SQL and web servers. > > > If we're going to have another round of this discussion, can all the > participants please make a solemn pledge to read RFC 3879 all > the way > through and to ask the authors, who are both regular participants > here, for help with the underlying concepts if any of them are > confusing? Please? > > -- > james woodyatt <[EMAIL PROTECTED]> > member of technical staff, communications engineering > > > > -------------------------------------------------------------------- > IETF IPv6 working group mailing list > [email protected] > Administrative Requests: https://www1.ietf.org/mailman/listinfo/ipv6 > -------------------------------------------------------------------- > -------------------------------------------------------------------- IETF IPv6 working group mailing list [email protected] Administrative Requests: https://www1.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
