On Apr 4, 2012, at 9:39 23PM, David Meyer wrote:
> On Wed, Apr 4, 2012 at 6:31 PM, Steven Bellovin <[email protected]> wrote:
>>
>> On Apr 4, 2012, at 5:21 35PM, Noel Chiappa wrote:
>>
>>>> From: Doug Barton <[email protected]>
>>>
>>>> My comments were directed towards those who still have the mindset,
>>>> "NAT is the enemy, and must be slain at all costs!"
>>>
>>> In semi-defense of that attitude, NAT (architecturally) _is_ a crock - it
>>> puts
>>> 'brittle' (because it's hard to replicate, manage, etc) state in the middle
>>> of
>>> the network. Having said that, I understand why people went down the NAT
>>> road
>>> - when doing a real-world cost/benefit analysis, that path was, for all its
>>> problems, the preferable one.
>>
>> NAT didn't really exist when the basic shape of v6 was selected.
>
> Perhaps, but that it would happen is obvious (even to the most causal
> observer).
I do not agree. I remember discussing the concept with folks, a couple
of years before that; we agreed that NATs would be very challenging
because of the need for protocol-dependent packet inspection and
modification. Add to that an underestimate of how long it would take
before v6 was adopted, and a gross underestimate of how large the
Internet would be -- remember, IPng happened before the Web explosion --
and it was very easy to ignore the possibility of NAT, let alone the
renumbering and (questionable) firewall benefits of it. In retrospect,
sure, but in 1993-1994? It was not at all obvious.
--Steve Bellovin, https://www.cs.columbia.edu/~smb
