Mans Nilsson wrote:
With proper layering, network addresses including IP ones, certainly,
uniquely identify *hosts*.
However, with proper layering, *applications* only require uniqueness
of IP+Port, which is enough for the worldwide IPv4 network.
As a result, NAT won the battle against IPv6.
IPv6 addresses are free but useless.
With all due respect, you think about networks. I use and build
networks. And my experience is that IP+port is not enough.
Certainly, local uniqueness of IP addresses to identify hosts
is required even in private networks behind NAT. But, because
of layering, that's all.
I do have extensive experiences to use and build networks
with proper layering in mind.
We cope,
because a lot of technical debt is amassed in corporate and ISP /
access provider networks that won't change.
Sounds like abstract nonsense.
We don't cope because NAT is
good. Hardly a workday goes past without me thinking "If I could address
this computer uniquely I'd go home earlier and with less grey hair".
The reality is that application servers only need globally unique
and stable IP+Ports.
You can address application servers with them.
We must do better.
As IPv6 is worse than IPv4 with NAT, feel free to propose a new
network protocol.
Masataka Ohta
