Brian E Carpenter <brian.e.carpenter@xxxxxxxxx> wrote: > The major problem with the story is that it confounds IANA runout > (objectively predicted for 2011) with when ISPs run out of IPv4 space > (which is not so easy to predict, but 2015 is a popular estimate). The > rest is pretty good for a story in the non-technical media, IMHO. More generally - and this is not a problem I have with the CNN article, just in general with IPv4 depletion conversations - I've been hearing about imminent IPv4 address depletion for 15 years or maybe 20 by now. - We were going to run out of Class C's, but then we converted to CIDR so were no longer bound by the rigid old classes and got to allocate addresses much more efficiently, buying many years. - We were going to run out of blocks to allocate even with CIDR, but lots of institutions adopted NAT so that places that would've needed large blocks started being able to make do with /25s or similar sizes for their few public IPs. - We were going to run low on public IPs despite NAT due to the rapid growth of web servers, but we got name based virtual hosting which let lots of web servers share the same IP. ... what's next? Carrier-based NAT? Virtual-hosting encrypted http? Actually using IPv6 en masse? Something else? It seems like the limits we're running up against aren't really a matter of growing demand vs. dwinding supply; for more than that, the limits are based on our cleverness in coming up with new ideas to conserve or use our IPv4 address supply more efficiently. We've had several large shifts of this sort and each time we buy years of time. Each such shift also has a cost, though it varies - name based virtual web hosting has relatively little cost and is a big win; CIDR was a hard transition but once done it's all win and no lose; Heavy use of NAT causes lots of problems and will continue to. But when it comes to "we're 1-2 years away and need to buy more time!" we always seem to end up with another one of these clever new ideas instead. Will there come a time when the least-cost clever "new" idea is an actual transition to IPv6? Probably, but I don't know when and I don't know that it makes sense to assume that is the next one, or to estimate which year it'll be. > You can find Daniel's recent talk at http://www.ipv6.ie/summit2010/. I can find a link to his talk on that site, but each time I click on that link I get a quickly-broken TCP connection. Overloaded, perhaps? -- Cos _______________________________________________ Ietf mailing list Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf