I disagree with Keith on some basic assumptions. IPv6 is not a software upgrade in its' dominant mode. IPv6 was done with the belief that the raw number of systems will grow huge enough that 2**32 is not enough. There was this CIDR thing created to solve this other problem.
In terms of raw numbers, IPv6 deployment will take the form of hardware purchases for IPv6 nodes that do not exist today: 1) Cell phones (historically <2 yr replacement cycle) 2) PCs with IPv6 installed (less than 5 yr replacement cycle) 3) new devices that plug into residential networks (mostly new) We should note IPv6 has been planned, products have been built and deployment will occur. It is being driven by people who have a vested interest in having a solution to the address run-out problem. (good news in the last 10 years is that Internet has gotten really good at deploying HTTP proxies, something we did not really bet on back in 1991/1992. This is going to aid transition immensely as we move forward). I concur that the routing guys have some work in front of them. May I suggest people take a closer look at hierarchical routing, combined provider and geographic hierarchies, and adult supervision? Regards, peter