Re: [v6ops] Eric Rescorla's No Objection on draft-ietf-v6ops-rfc6555bis-05: (with COMMENT)

[Eric Rescorla <[e-mail]>]

On Fri, Oct 20, 2017 at 8:28 PM, Lorenzo Colitti <[e-mail]> wrote:

> On Oct 21, 2017 08:17, "Eric Rescorla" <[e-mail]> wrote:
>
> But we also like ipv6 better than Ipv4 because it is cheaper.
>>
>> From a mobile network operator perspective, ipv4 NAT paths are
>> dramatically more expensive (cost creating and maintaining session state in
>> hw on the CGN, complex large scale stateful software , ALG bugs, buying
>> public IPv4 address to feed the CGN ...., per transaction or per port block
>> in time logging for LEA, secure storage of said logs, ... ).
>>
>
> That's reasonable, I suppose, but (a) not everyone is on mobile and (b)
> the endpoint's interests may not align with yours.
>
>
> Those factors are in no way specific to mobile networks.
> IPv4 addresses and NATs cost money for everyone. Stateless translation
> doesn't use NAT, but because it's stateless, port space has to be assigned
> in advance, so it consumes more IPv4 space than stateful translation.
> Public IPv4 to users is already infeasible for new entrants, and will be
> infeasible in the sort to medium term incumbents.
>
> I don't see any cheaper alternative than IPv6. Do you?
>

As I said, the endpoints have different incentives, namely to get the best
performance for their users.

If IPv4 and IPv6 paths are equally fast for the user, then delaying
attempts to connect v4 in cases where v4 resolves first makes the user's
experience slower. That's not to say that there's not some public good
argument for doing that anyway, but if so, that should be explained, not
just smuggled into some protocol constant.

-Ekr