Re: [v6ops] I-D Action: draft-colitti-v6ops-host-addr-availability-01.txt

[Lorenzo Colitti <[e-mail]>]

On Wed, Jul 29, 2015 at 1:54 PM, Ted Lemon <[e-mail]> wrote:

> Or for laptops that want to run VMs. Or for future protocols that need
> more space, or for applications that want per-application IP-addresses. Or
> anything else.
>
> Laptop VMs will have DHCP clients, so there’s no reason not to use DHCP.
> Only Android doesn’t have a DHCP client.
>

DHCPv6 is not the issue. The issue that we're recommending that networks
provide enough addresses *at connection time*. If we recommend that
networks should assign every device a /120 (256 addresses) *at connection
time*, then a device getting the /120 cannot respect the recommendations
with respect to any nodes behind it.

> The draft only recommends using DHCPv6 PD on if the network "requires
> explicit requests for address space". That rules out anything running
> SLAAC, which is supported by the vast majority of IPv6 deployments today.
> If you want the draft to recommend that networks should not require
> explicit requests for address space, then it can do that.
>
>
> I do not see how your response connects to what I said.   Either we can
> afford for every host to have a /64, or we can’t.   If we can’t, then we
> shouldn’t be delegating /64s to hosts.
>

Your argument does not take into account the reality that RIR policies are
different for different use cases. More specifically, it does not hold
water due to the fact that current practices allow assigning 4096 times as
much address space (/48) to a small/medium enterprise as ISPs often assign
to a small residential user (/60).

More in detail:

   1. Given current RIR policies, we can afford to assign a /48 to every
   enterprise network that needs to support up to
   64k general-purpose endpoints. We have plenty of /48s.
   2. Given current RIR policies, we afford to assign a /64 per device to
   every enterprise network that needs to support more than 64k
   general-purpose endpoints (there aren't that many of these, and we have
   plenty of /40s).
   3. Given current ISP assignments, we cannot afford to assign a /64 per
   device in a home network that only has a /60.

So the only problem here is #3 - home networks. But because home networks
use SLAAC, we don't need to assign a /64 to every host.