Re: myth of the great transition (was US Defense Department forma lly adopts IPv6)

[Iljitsch van Beijnum <iljitsch at muada.com>]

On donderdag, jun 19, 2003, at 13:49 Europe/Amsterdam, J. Noel Chiappa 
wrote:

> > Maybe NATs are, in fact, a result
> > of a very deep problem with our architecture.

> My take is that NAT's respond to several flaws in the IPv4 
> architecture:

> - 1) Not enough addresses - this being the one that brought them into
> 	existence.

Since there are 1.5 billion unallocated addresses lying around in some 
storage room at IANA, the IPv4 address shortage problem in itself can't 
be the reason for the existence of NAT. The real problem is that ISPs 
are unwilling to give out addresses to customers in a way that 
customers find acceptable and affordable.

> - 1a) Local allocation of addresses - a variant of the preceeding one, 
> but
> 	subtly different; NAT's do allow you to allocate more addresses
> 	locally without going back to a central number allocation authority,
> 	which is very convenient.

Right.

> I think that if you look at the points I listed above, the market has 
> clearly
> decided that IPv4+NAT (for all its problems, with which people are I'm 
> sure
> reasonably familiar, given the many years NAT has been in service 
> widely) is
> the most cost-effective solution to providing them. The IETF really 
> needs to
> sit and ponder the implications of that.

Designing a NAT architecture that doesn't have the disadvantages 
current NAT has wouldn't be much of a challenge. A little outside 
address discovery here, some dynamic server port assignment there, and 
we're well on our way. However, this would still require massive 
changes to all applications (not just the ones that don't work with NAT 
today) and to deployed NATs. But instant deployability is exactly what 
makes NAT so prevalent today. If implementing NATng is as much trouble 
as implementing IPv6, why bother?