On Wed, Feb 9, 2011 at 3:05 PM, Iljitsch van Beijnum <iljitsch@muada.com> wrote:
On 9 feb 2011, at 20:53, William Herrin wrote:
* Carrier NAT buys us enough years to build an IPv4 successor
You're kidding, right? How long did it take exactly to get where we are now with IPv6? 18, 19 years?
Tech like carrier NAT theoretically yeilds address reclamation in excess of 80%. Internet-facing servers must consume IP address. It's convenient for client computers to do so as well, but not critical to the general function of the Internet. 20 years is about what that level of reclamation buys before we're out of addresses again. As you say -- enough time to develop a protocol and get it into the software and hardware.
* Next protocol should really be designed to support interoperability with the old one from the bottom up. IPv6 does not
That's because it's not the headers that aren't incompatible (the protocol translation is ok even though it could have been a bit better) but the addresses.
No, it's because decisions were made to try to abandon the old DFZ table along with IPv4 and institute /64 as a standard subnet mask. But for those choices, you could directly translate the IPv4 and IPv6 headers back and forth, at least until one of the addresses topped 32 bits. The transition to IPv6 could be little different than the transition to 32-bit AS numbers -- a nuisance, not a crisis. You recompile your software with the new IN_ADDR size and add IP header translation to the routers, but there's no configuration change, no new commands to learn, etc. Regards, Bill Herrin -- William D. Herrin ................ herrin@dirtside.com bill@herrin.us 3005 Crane Dr. ...................... Web: <http://bill.herrin.us/> Falls Church, VA 22042-3004