Current Consensus on IPv6 Customer Allocation Size

David Farmer farmer at
Fri Aug 31 21:43:36 CEST 2012

The reall issue isn't how many subnets, and your right no one wants to 
manage them.

So, If we can agree there is some likely hood of more than one subnet, 
then the question is how many bit do you need for a algorithmic 
allocation scheme for the devices to automatically pick their subnets. 
Eight bits is more than enough for a human to manage putting all the 
subnets of almost any house in.  But, we just said no one want to manage 
it.  So eight bits is kind of small for algorithmic scheme that would 
cover +95% of the possibilities.  Its a lot tougher problem than most 
people relise, it doesn't seem like it should be but it is.  There is a 
lot just wired into our brains, that makes it easy for a human to adapt 
to the conditions, but algorithmic approches frequently aren't all that 

On 8/31/12 14:10 CDT, James Cloos wrote:
>>>>>> "MB" == Mark Blackman <mark at> writes:
> MB> More than 256 subnets in the home? Who would want to manage all of that?
> Don't be surprized to see (ether-)? peripheral lans hanging off general-purpose
> boxen, each needing its own /64.
> We also may end up with clusters-in-a-box replacing existing nodes;
> they'll need /64s for their internal lans.
> Virtual lans, conencting VMs w/in a node, could consume /64s, too.
> 65536 may be extreme, but I certainly see 257+ showing up.
> -JimC

David Farmer               Email:farmer at
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