Dual stack IPv6 for IPv4 depletion

Thu Jul 9 16:35:56 UTC 2015

> On Jul 9, 2015, at 08:42 , Matthew Huff <mhuff at ox.com> wrote:
> 
> What am I missing? Is it just the splitting on the sextet boundary that is an issue, or do people think people really need 64k subnets per household?
> 

It’s the need for a large enough bitfield to do more flexible things with auto-delegation in a dynamic self-organizing topology.

8 is 2x2x2 and there’s really no other way you can break it down. (2x4, 4x2, 2x2x2 is it.)

16 is 2x2x2x2 and allows many more possible topologies (4x4, 2x4x2, 2x2x4, 2x8, 8x2, etc.)

> With /56 you are giving each residential customer:
> 
> 256 subnets x 18,446,744,073,709,551,616 hosts per subnet.

The host count is irrelevant to the discussion.

> 
> I would expect at least 95.0% of residential customers are using 1 subnet, and 99.9% are using less than 4. I can understand people complaining when some ISPs were deciding to only give out a /64, but even with new ideas, new protocols and new applications, do people really think residential customers will need more than 256 subnets? When such a magical new system is developed, and people start to want it, can't ISPs start new /48 delegations? Since DHCP-PD and their infrastructure will already be setup for /56, it may not be easy, but it shouldn't be that difficult.

I would expect that basing decisions about limits on tomorrows network on the inadequacy of today’s solutions is unlikely to yield good results.

Further, I’m not so sure you are right in your belief. I suspect that there are many more networks in most households that you are not counting. Sure, those networks are currently usually disjoint, but do you really think it will always be that way in the future?

Every phone is a router. Ever tablet is a router. Cars are becoming routers and in some cases, collections of routers. Set top boxes are becoming routers.

Utility meters are becoming routers.

Laptops and desktops are capable of being routers.

> I know the saying "build it and they will come....", but seriously....
> 
> I'd rather ISPs stop discussing deploying IPv6, and start doing it…

I’m all for that, but do you have a valid reason not to give out /48s per end site? Just because /56 might be enough doesn’t cut it… I’m asking if you can point to any tangible benefit obtained from handing out /56s instead? Is there any problem solved, labor saved, or any other benefit whatsoever to giving out /56s instead of /48s?

If not, then let’s hand out /48s until we discover one.

Owen