Subject: Re: IP network address assignments/allocations information?

From: Pyda Srisuresh <[email-masked]>
Date: Tue, 30 Nov 1999 08:10:56 -0800 (PST)

--- Keith Moore <[email-masked]> wrote:
> > And yes, additional IP addresses were going to cost dramatically more.  NAT
> > was a simple case of economics... but on the other hand, I don't experience
> > any "lack" because of it.  I don't play UDP-based games or employ any of
> the
> > other relatively new protocols that are so sensitive to end-to-end-ness
> > (should they be? was that a valid assumption?), so a NAT is a great
> solution
> > for me.  
> 
> understood.  and you may never miss any of those distributed applications 
> or applications that want your end to be the "server" for the very reason
> that NAT prevents them from having enough market share to be successful.
> 
> i.e.  just because you don't know what you're missing doesn't mean that NAT
> hasn't done you harm.
> 

Keith - There is no denying that NAT devices break a bunch of applications 
and protocols. But, they did get us through the rough times when IP 
addresses are scarce and many people wanted to hop on the Internet. In a
way, NATs helped people keep their trust in IP and in the engineering 
community as a whole to come up with solutions that meet the need of the
time. Having said this, I do believe, people who market NAT devices should
warn customers of the limitations and not pretend like there arent any. 

There are some folks who believe NATs are behind the creation of private
addresses. The fact of the matter of the matter is the other way around.
People have been using private addresses to build their networks; People 
change their providers, but do not want to renumber their networks each 
time they change their providers. NATs were able to provide connetivity 
to external world without requiring them to renumber their addresses in 
the private network.

If nothing else, I would say that NATs were able to bring to bear an 
awareness in the minds of protocol/application designers a need to
seperate names and addresses. That in itself seems like an accomplishment.
 
> > NAT would be bad if an ISP were using it to artificially expand its address
> > space; the use of NAT at the "small-time" end user's site seems quite
> > practical and beneficial, especially in a world where ISPs are going to
> hold
> > up non-naive users for ransom.  Cheers -- Ian 
> 
> if you think of NAT as a short-term strategy and are fully aware of its
> limitations, it probably won't cause you much harm as an individual.  
> 
> then again, there are dozens of products out there claiming to offer
> something like "internet connection sharing" without bothering to mention
> the limitations of that approach...which seems like misleading advertising
> at best.
>

I agree.
 
> Keith

regards,
suresh
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---

From: Keith Moore <[email-masked]>
Date: Tue, 30 Nov 1999 11:45:42 -0500

> time. 

the latter statement seems a bit extreme.  one could as easily make the 
statement that NATs are giving the engineering community a bad reputation 
in the eyes of the public, given that so many problems are now being caused 
by them.  (also an extreme statement, but no less so than the first one)

I'd rather just say that (a) NATs are a short-term fix with limited 
applicability, (b) for the long term general solution we will need 
longer addresses - as in IPv6, and (c) with careful definition of
adaptation mechanisms such as NAT-PT and 6to4, devices with NAT
and ALG functionality can be part of a transition path to IPv6. 

> to external world without requiring them to renumber their addresses in 

absolutely true.

> seperate names and addresses.

though folks are indeed looking into the implications of such a separation,
it's far from clear that this is a 'need'.  every additional layer 
of indirection imposes a cost in terms of money, performance, reliability, 
and flexibility - all of which need to be weighted against whatever
advantages might be obtained from such a separation.

Keith

---

From: Keith Moore <[email-masked]>
Date: Tue, 30 Nov 1999 11:45:42 -0500

absolutely true.

Keith