On Sun, Jan 28, 2007 at 12:36:38AM -0800, Joe wrote: > whats sad is how many people will never let go of NAT after they migrate > to ipv6.
It's not sad; for many people it would be essential. How would you like your 48-bit MAC address to become a permanent cookie, following you about whenever you access the Internet? And if you need to change ISP, and therefore get a new address allocation, many people would rather just put in some NAT at the border than take the pain of network renumbering (which IPv6 doesn't make any easier than IPv4) Stuart Henderson wrote: > 128-bit gives you a *lot* of address space. > > 18 million million million /64's, each of which can hold > 65536 x the total number of possible 48-bit MAC addresses. Nope. One year ago, France Telecom applied for, and was granted, a /19 of IPv6 address space. Since the first three bits are fixed in the unicast addressing plan, this means that a single ISP has already taken 1/65,536th of the total available. This all boils down to dogma on the part of the IPv6 designers - e.g. "thou shalt not have server-based address autoconfiguration". If IPv6 had stuck with DHCP, which everyone knows and understands, then you could just give each customer a /96, rather than a /48 as demanded by IPv6, and we would have addresses for aeons. Not so now. So I argue that IPv6 doesn't solve any of the problems which IPv4 has - not even address depletion - and adds plenty of its own. As a result, I don't see much commercial reason to roll it out, and certainly no commercial reason to switch off the existing IPv4 Internet. Arguments here: http://pobox.com/~b.candler/doc/misc/ipv6.txt Regards, Brian.
