Re: the race to the bottom problem

[Mikael Abrahamsson <[e-mail]>]

On Sat, 7 Nov 2020, Lorenzo Colitti wrote:

> The logical consequence is that we end up at /128. This is particularly
> risky because any operator with lots of experience with IPv4 will find "one
> /128 per host" obvious, expected and natural. One device has one IP
> address, right? And once get to that point, we'll need to bring back NAT in
> order to extend further. That would pretty much make the entire transition
> to IPv6 pointless. We might as well have stayed with IPv4.
>
> Personally I think that once there's more industry experience and IPv6 is
> widely deployed in all network types (say, once we reach 80% of the
> internet, and many networks are IPv6-only), we might be able to safely move
> the bottom, once. But it's much too early for that.

I still fully agree with this. To this day, I run into people who want to 
via DHCPv6 assign a single address to each host. They do not care that 
this host might be running docker containers, VMs or whatever, that might 
benefit from having a GUA. To them it's "obvious" way to do, because 
that's how it's "always" been done.

They've already completed the race to the bottom, and indeed that's a 
/128.

We see all this /64 deployment because ISPs are saying "why more, there is 
just a single LAN?" and then /64 PD is the natural result of that thought 
process. This is the *only* thing stopping them from assigning smaller 
subnets. I'm sure there are plenty who started out with /120 and then 
discovered that didn't work, did some research and discovered "oh, I need 
/64" and then that was that.

I do agree we should try to solve this problem so that my machine can get 
for instance a /112 assigned to it in one go, basically "prefix 
registration" so the upstream router can assign a large subnet to a host 
and install a route for that. Still, that doesn't solve the nested doll 
problem with router->router->router->machine->VM->docker etc that we want 
to support.

I don't know how to solve this, but letting go of the /64 limit makes me 
very Fearful, Uncertain and Doubtful about the future.

-- 
Mikael Abrahamsson    email: [e-mail]