At 02:53 PM 1/14/2013, James Harper wrote:
70 trillion possible vendor allocated MAC addresses (46 bits), and currently 7 billion people on earth. 10000 each. I suspect that will be enough for now, but they never get reclaimed (AFAIK) so they won't last forever.
And there are some duplicates running around. Shouldn't be, but I have seen duplicate MAC addresses in the real world. It was only through detailed troubleshooting of some weird network issues that I discovered this. :)
This article discusses some of the merits of the 64 bit subnet address - http://etherealmind.com/allocating-64-wasteful-ipv6-not/. I almost stopped reading when I read that "IPv6 addresses are 296 times more numerous than IPv4 addresses" until I realised that they meant 2^96.
A lot of these arguments end in the circular statement that "subnets are 64 bits because SLAAC is 64 bits", so I'm yet to be convinced.
Agree, the reasoning is very circular. I'm not convinced either, and I'm sure usage changes down the track will see changes in addressing and routing policies, just as happened with IPv4 over the years. 73 de VK3JED / VK3IRL http://vkradio.com