Subject: RE: Stupid NAT tricks and how to stop them.

From: "Hallam-Baker, Phillip" <[email-masked]>
Date: Mon, 27 Mar 2006 21:21:01 -0800

> From: Keith Moore [mailto:[email-masked]] 

> > 	I agree, but that opportunity may be to enhance NAT 
> rather than throw 
> > it away (you state something similar in your conclusion).
> 
> As an engineer, the right thing to do is to transition away 
> from NAT (along with IPv4), so that eventually it can be discarded.

As an engineer I think of COST vs BENEFIT.

In this case the benefit to running NAT on my home network is that it saves
me $50 per month in ISP fees, means I have wireless service to the whole
house and means that guests can easily connect.

I have never seen a coherent, rational argument as to why the network
numbering on my internal network should be the same as the network numbering
on the Internet. All I hear is a restatement of the original claim, the 'no
you didn't' mode of argument.

> I'm not a marketing person, but if I do my best to think like 
> one, I suspect that the way to market this transition is not 
> to say "this new box helps you get rid of NAT" but instead 
> "this is a new, enhanced NAT" 
> (or since they don't actually use the word NAT to talk about 
> consumer gear, call it something like "IPv6-ready Enhanced 
> Address Management")

People will still want to do NAT on IPv6. 

_______________________________________________
Ietf mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/ietf

---

From: Keith Moore <[email-masked]>
Date: Tue, 28 Mar 2006 00:48:13 -0500

> house and means that guests can easily connect.

one immediate benefit to my running IPv6 on my home network is that I 
can access any of my machines from anywhere else on the network (via 
6to4), as long as I'm not behind a NAT.  my home network also has a v4 
NAT, so it's not as if they're mutually exclusive.

> on the Internet. 

obviously you've never tried to write a distributed application in a 
NATted network.  and presumably you never tried to do anything with UUCP 
mail (which had naming conflicts) or a large DECnet (which had address 
conflicts).  the problems are immediately obvious to those of us who 
have had to deal with those disasters.

in brief: one reason is so that apps can have the same view of the 
network regardless of whether they're hosted on your internal network, 
or on an external network, or on a combination of the two.  it's MUCH 
simpler if apps don't have to worry about the fact that host A has 
address A1 from network X and address A2 from network Y.  particularly 
since in a network with scoped addresses, hosts don't really have any 
way of knowing which network they're on.

there are other reasons also: routing, coherent network management, DNS 
consistency.  a network with scoped addressing is like a city where all 
of the streets have the same name.  it becomes pretty difficult to navigate.

> People will still want to do NAT on IPv6.

true.  people do all kinds of evil things that break the net. our 
protocols will only work to the extent that people follow the 
specifications.  when people start breaking things, the protocols and 
applications start failing.  NAT is a good example.

in ipv6, we can provide better ways of solving the problems that people 
think they're solving with NATs.  if we fail to do that, or if people 
insist on using NATs anyway, we're screwed.  but that's not a reason to 
give up without trying.

either do something to help or get out of the way.

Keith

---

From: Tim Chown <[email-masked]>
Date: Tue, 28 Mar 2006 10:10:43 +0100

Interesting discussion.

Keith is hitting all the nails on the head.   Phillip seems to suggest
that consumers buy NATs out of choice.  They don't have any choice.

I surveyed my final years students last month.  Just four have a static
IPv4 allocation for their home network, and only one has more than a /32
for use internally.  ISPs just don't give you a choice (unless you are
prepared to pay a non-negligible fee).

If you deply IPv6 NAT, you may as well stay with IPv4.  The first ISPs
offering IPv6 are offering /48's here.   The allocations to FT etc (they
have a /19) are clearly made on the basis of end site /48's.

See also http://www.ietf.org/internet-drafts/draft-ietf-v6ops-nap-02.txt

We have deployed IPv6 in our enterprise (throughout).  We're seeing some
early benefits from (student) driven new services.  Students are also using
transition mechanisms to enable simpler use of applications between homes 
(rather than battling a NAT out and a NAT in on communication paths).

No regrets from deploying, no significant issues either for the existing
IPv4 service.  And there's more than just address space to take advantage
of, like embedded RP for multicast applications.

Tim

-- 
Tim/::1

---

From: "Anthony G. Atkielski" <[email-masked]>
Date: Tue, 28 Mar 2006 20:46:41 +0200

Keith Moore writes:

> true.  people do all kinds of evil things that break the net.

Yeah ... like charging for IP addresses that should be free.