Once IPv6 is sufficiently ubiquitous (rough estimate, but say 900+ of the Alexa 1000 sites have IPv6 and ~95% of eyeball networks), you'll see a rapidly declining desire to pay the increased cost of supporting IPv4. Combine that with the fact that as the internet continues to try and grow, the longer IPv4 remains relevant, the more cobbled, hacked, layered, NATted it will become. All of these additional heroic measures to keep IPv4 running will have a huge and multiplying cost. The network will be increasingly complex and harder to troubleshoot while also becoming increasingly fragile. The end user experience will be degraded by the additional layering while the service providers costs to provide that service are increasing because of the need to provide additional equipment and man-hours to manage the growing complexity. As the costs of supporting IPv4 go up, ISPs will have no choice but to pass that cost along to customers. Eventually, some IPv6 ready customers will not want to continue subsidizing the IPv4 costs and will insist that the cost increases related to IPv4 be billed to the IPv4 customers. Once IPv4 becomes a separate and increasing charge on people's internet bills, the economics will further drive the transition away from IPv4. Will we have isolated pockets of IPv4 within organizations for years to come? Sure. How long will IPv4 remain the lingua franca of the internet? I'm pretty sure that will be less than a decade and likely ~5 years at this point. Owen On Mar 12, 2013, at 10:32 , David Barak <thegameiam@yahoo.com> wrote:
From: Owen DeLong <owen@delong.com>
Dual stack is a (very) temporary solution while waiting for some others to catch up and deploy IPv6. Contemplating dual-stack as a permanent or long-term solution ignores the extent to which IPv4 is utterly unsustainable at this point. Owen
Owen, when do you think IPv4 is going to go away to the point that it will no longer be necessary to carry it? We may be using "long-term" to mean different things, so I'm curious to see what you mean by that.
David Barak Need Geek Rock? Try The Franchise: http://www.listentothefranchise.com