IPv6 Address Planning

Wed Aug 10 16:29:50 UTC 2005

On 10-aug-2005, at 18:03, Leo Bicknell wrote:

> IPv6 allocations in the host portion (with /64 boundaries) are
> sparce, even for the largest networks.  The number of hosts becomes
> unimportant.  The question we need to ask is how many independant
> subnets will they need.

> This is why many people are proposing a /56 for home users, as it
> gives you 256 subnets.  Still more than most people will need.

> Others have proposed /52 and /60, since many want to claim DNS is
> easier if done in nibbles.

And the extra precision offered by the intermediate values isn't  
really required at this point in the discussion.  :-)

I'm very much oppossed to /56 because it's still more than most users  
need. In and of itself that doesn't matter, but it's also less than  
what some users need. This creates the situation where people try to  
make do with a /56, find out that they need a /48 after all (all  
those /64 ptps...) and have to renumber. I.e., /56 provides too much  
potential for shooting yourself in the foot.

I think we should go for /60 for (presumably) one-router networks.  
That's still 3 to 5 times as many subnets as most of those will need.  
Anyone else should get a /48.