On 2 Dec 2009, at 12:03, <michael.dillon@bt.com> wrote:
As long as we have IPv9 ready to deploy by 2050, we can avoid any risks of IPv6 addresses running out.
First, I find it staggering that anyone is contemplating -- even in passing -- a replacement for IPv6 and a shopping list of features for that when the level of IPv6 uptake is so low. It's unwise to assume there is no risk of IPv6 addresses running out. The same mistake was made ~25 years ago when ARPAnet transitioned from NCP to IP. A 32-bit address space was then considered too big to fill. ISTR similar claims being made when 32-bit and 64-bit CPUs were introduced: nobody could ever use all of that address space. The same goes for disks. These are almost always full, no matter how big they get. A variant of Parkinson's Law probably applies here, namely bloat and inefficiency will always expand to fill or exceed whatever addressing capability is provided. Remember too that since each customer will in all probability get a / 64 from their ISP, the effective size of the IPv6 address space in the core of the network is 64 bits. It's still a very big number: just not as big as first thought. And that won't last long if the world and its dog gets a /24 or more for 6RD or whatever...
We don't even have to start work on the IPv9 design until 2030 or so, which gives plenty of time for people to gain large-scale IPv6 operational experience.
Assuming there is wide-scale IPv6 deployment and usage by then. BTW if your claims are correct, this presumes the IETF can complete the development of IPv9 in 20 years. Which seems... well... optimistic. :-) The DNSSEC protocol been chugging through the IETF machine for over 10 years.