Subject: Re: Enforcing unreachability of site local addresses

From: Tim Hartrick <[email-masked]>
Date: Thu, 12 Dec 2002 18:12:35 -0800 (PST)

Margaret, Bob,

> 
> >In my opinion, the only way that we will stop people from using NAT
> >(with or without IPv6 site-local addresses) will be to provider better
> >(architecturally cleaner, more convenient, more functional) mechanisms
> >for people to get the same benefits that they get from NATs today.
> >Although NATs may have started as a response to address space shortage,
> >today their use is driven by the needs for provider-independent addressing
> >and convenient access control.  So, we need to work on better ways to
> >provide those things in IPv6.
> 
> I am not sure that this is really true.  When I was looking for a new DSL 
> provider I found that in many cases I could get service at a specific 
> bandwidth with a singe address for about $60 a month.  If I wanted a /29 
> instead, it would cost about $30 more a month.  50% more for 6 usable 
> addresses!  I think this is fairly common.  The lower cost DSL providers 
> doen't even give the user to choice to get more addresses.  People are 
> still being forced to run NAT in response to address scarcity.  We could 
> only tell for sure if people would still run NAT for other reasons if 
> addresses were readily available.
> 
> I ended up finding a different ISP who charged more money, but gave me more 
> bandwidth and the addresses I wanted.  Most people would not be willing to 
> do that and would be forced to run NAT.
> 

I believe that Bob has it right here.  Enterprises may well use NAT for
provider independence and easier multi-homing, but in the home and
small business area NAT is driven by address scarcity.  That address scarcity
is artificial in many cases.  ISPs can charge for address space so they do.
No one is going to give up NAT unless they can get all the address space
they want and only be charged for bandwidth.  That will require some business
model surgery on consumer ISPs.

As I have said multiple times during this long debate, we need to work
on solutions in both these spaces.  To fix the "ISP can charge for address
space so they do" part we need to have a renumbering solution that doesn't
require home and small business users to break internal communication in
order to renumber.    We kind of had that with the router renumbering
specification but that appears doomed at this point.  Without that lever in
the hands of consumers, ISPs will simply continue to charge for "extra"
addresses and NAT will follow.  Even with it NAT might follow but without
it NAT is a near certainty.  If these renumbering solutions scale to the
enterprise, all the better but the enterprise also has to deal with multi-
homing.  

Tim Hartrick
Mentat Inc.
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From: Keith Moore <[email-masked]>
Date: Fri, 13 Dec 2002 12:19:59 -0500

> is artificial in many cases.  ISPs can charge for address space so they do.

okay, but don't forget commodity pricing.  "single IP address" is the
market norm, it's what most users currently expect.  anything different 
would be more expensive just because of the nuisance factor.

that, and use of NAT is the current "conventional wisdom".  this is 
changing, but it's taking awhile.  also NATs are in some sense invisible.
I don't know of any vendor that labels SOHO NAT boxes for what they are - 
they just claim that they are "connection sharing" boxes, or worse, 
"routers" - as if translating addresses were inherently a part of IP routing.

Keith