I guess my previous message was not sent to the list this morning (the connectivity is terrible here ;-), so I forward it again
> Margaret, > > I think we have no other choice than (B), both technically, and from the "marketing" >perspective of going or not to deploy IPv6. > > I think the scalability could be an issue, but also believe that we have enough time >to work on new solutions, new routing protocols > (that in the long term will be anyway needed - multihoming), probably, and > thinks like regional IX's, could help. > > Regards, > Jordi > > ----- Original Message ----- > From: "Margaret Wasserman" <[EMAIL PROTECTED]> > To: "Erik Nordmark" <[EMAIL PROTECTED]> > Cc: "Keith Moore" <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> > Sent: Sunday, January 26, 2003 1:30 PM > Subject: Re: Enforcing unreachability of site local addresses > > > > > > >I think, but I'm not sure, that this assumes that we will have a scalable PI > > >scheme some time in the future (presumably by separating PI identifiers > > >from PA locators). > > > > Actually, this is quite tricky... > > > > If we _don't_ allocate PI addresses soon, enterprises will demand > > IPv6 NAT to allow them to use provider-independent internal numbering. > > This is the model that they use today, and they will probably continue > > to use it unless a more compelling model (such as provider-independent > > globally-routable addressing) is available. > > > > But, if we do allocate PI addresses soon, we will need to do that without > > any certainty that we can come up with a scalable PI routing scheme. So, > > we may be creating a serious scaling problem further down the road. There > > is no good way to predict when we would hit this scaling problem, as > > that will depend on many factors including the rate of adoption of IPv6, > > the number of PI addresses allocated/used, the rate of increase in the > > speed/memory size of routers. But, I've been told by ISPs who lived > > through the CIDR transition in IPv4 that this _really_ isn't something > > that we want to repeat for IPv6. > > > > If/when we do find a solution to the route scaling problem, there is no > > real assurance that it will be backwards compatible with existing IPv6 > > address allocations. In fact, it may even require changes to the IPv6 > > protocol. > > > > Some folks have argued that easy renumbering would eliminate the need > > for enterprises to have provider-independent addressing, but I don't > > agree. Addresses are stored in many places in the network besides > > the interfaces of routers and hosts, such as access control lists, > > configuration files, .hosts files, DNS configurations, ACL lists, etc. > > In many cases, addresses are stored in nodes on other subnets. So, > > being able to renumber the interfaces of hosts and routers on a > > particular network or subnet doesn't even solve half of the problem. > > > > So, what do we do? > > > > Choices seem to be: > > > > (A) Continue with PA addressing, and accept that enterprises will > > use IPv6 NAT to get provider-independence. > > (B) Allocate PI addresses, and trust that we can determine a > > scalable PI routing scheme before we hit route scaling > > issues in the IPv6 backbone. > > > > NAT has huge costs, making the Internet more expensive and less efficient, > > affecting the resiliency of networks, and limiting our ability to deploy > > secure, innovative Internet applications and services. It does solve > > the route scaling issues, but the cure may be worse than the disease. > > We may be able to solve the route scaling issues in a less damaging way > > later, but once folks start deploying IPv6 NAT on a large scale, we > > will never be able to get rid of it. > > > > So, I would make an informed decision to pursue choice (B), in full > > knowledge that it might create a route scaling issue further down the road. > > I'm not sure that we'll ever reach anything resembling "IETF consensus" on > > that choice, though. > > > > Margaret > > > > > > > > > > > > > > > > At 06:08 AM 1/22/2003 +0100, Erik Nordmark wrote: > > > > I suspect we all agree that crushing the routing system would be bad . > > > > It seems like the question is what mechanism (other than ambiguity) > > > > would be sufficient to prevent that happening. > > > > > >Assuming we have the "SHOULD NOT be routed globally" in the spec. > > > > > >Then if the PI addresses come from a different space than the PA addresses > > >I think there is a way out. > > >When the routing gets strained ISPs can unilaterally decide to filter out > > >PI routes (or have a different prefix length filter for the PI space > > >than for the PA space). > > > > > >ISPs are unlikely to do this for the PI routes their direct customers are > > >using, since it would upset their customers. But they should be able to do it > > >for the PI routes coming from elsewhere. And the ISPs could do this type of > > >filtering on the PI space from day one - "pay me money if you want me to > > >carry your PI route" - on an individual ISP basis. > > > > > >Could this work? > > > > > >I think, but I'm not sure, that this assumes that we will have a scalable PI > > >scheme some time in the future (presumably by separating PI identifiers > > >from PA locators). > > > > > > Erik > > > > > > > > >-------------------------------------------------------------------- > > >IETF IPng Working Group Mailing List > > >IPng Home Page: http://playground.sun.com/ipng > > >FTP archive: ftp://playground.sun.com/pub/ipng > > >Direct all administrative requests to [EMAIL PROTECTED] > > >-------------------------------------------------------------------- > > > > > > -------------------------------------------------------------------- > > IETF IPng Working Group Mailing List > > IPng Home Page: http://playground.sun.com/ipng > > FTP archive: ftp://playground.sun.com/pub/ipng > > Direct all administrative requests to [EMAIL PROTECTED] > > -------------------------------------------------------------------- > > > ********************************* Madrid 2003 Global IPv6 Summit 12-14 May 2003 - Pre-register at: http://www.ipv6-es.com Interested in participating or sponsoring ? Contact us at [EMAIL PROTECTED] -------------------------------------------------------------------- IETF IPng Working Group Mailing List IPng Home Page: http://playground.sun.com/ipng FTP archive: ftp://playground.sun.com/pub/ipng Direct all administrative requests to [EMAIL PROTECTED] --------------------------------------------------------------------
