Dan, On 2008-02-19 05:51, Dan York wrote: > Brian, > > On Feb 17, 2008, at 10:33 PM, Brian E Carpenter wrote: >> On 2008-02-18 14:30, Terry Gray wrote: >>>> >>> Unless/until enterprise (or even home) network operators have some >>> number of bits of address to call their own, without risk of forced >>> change or being held hostage to their ISP, you will have NAT for v6 >>> just like for v4. I think you can take that to the bank. >> >> No, you'll have pressure for PI space, which we already see. >> As for how to make PI-addressed sites globally reachable without >> a scaling problem for the WAN routing system, see the RRG list, >> which is really aimed at that challenge IMHO. There's certainly >> no need to rush into NAT for that reason. We don't have an >> *imminent* scaling problem in IPv6 WAN routing. > > So if I understand you correctly, you believe that: > > 1. ULAs will give enterprises the addressing autonomy that they seek (as > RFC 1918 addresses do with IPv4) Correct. That's available today. > ; but that > 2. Enterprises will NOT need to use NAT to make those ULAs globally > reachable (instead using work going on in RRG). No. When a client system wants to go outside the corporate network, it will need to use a second address that belongs to a globally routable prefix. But there's no reason to care about whether that address has a particularly long lifetime, so it really doesn't matter whether it's from PI or PA space or whether it will change next time you reboot the client. Obviously, external corporate servers (presumably living in a DMZ) need stable addresses and if they are using PA space, they can only multihome by using multiple simultaneous PA prefixes. This is running code, and it's not the same as IPv4. The long term scaling issue is how to support PI multihoming. There's no doubt there will be corporate demand for that. > > Is that correct? > > I will admit that I haven't followed the RRG list at all, but I find it > hard to wrap my brain around how precisely this would be done (outside > of servers full of proxies, ALGs, etc.). The RRG direction is essentially map-and-encap, but that is a long discussion. > Perhaps I've just spent far > too long in enterprise-land where everything is NAT'd and proxied at the > firewall with IPv4. Can you point folks like me to some specific work > on this that we can read up on? I wouldn't presume... try http://www3.tools.ietf.org/group/irtf/trac/wiki/RoutingResearchGroup Brian > >> Yes, which is why I'm a strong supporter of ULAs. There's no reason >> your printers or internal-only servers need globally reachable addresses. > > > Agreed. > > Regards, > Dan > _______________________________________________ Ietf@xxxxxxxx http://www.ietf.org/mailman/listinfo/ietf