Subject: RE: "unique enough" [RE: globally unique site local addresses]

From: "Michel Py" <[email-masked]>
Date: Thu, 21 Nov 2002 10:52:45 -0800

Pekka,

> Pekka Savola wrote:
> One idea IMO is that we don't even want to be aim for
> total, provable, complete uniqueness.
> Looking at some requirements, I believe "unique enough"
> is good enough.
> Take your name, address, phonenumber or whatever (it
> must be long enough, though), apply a hash function
> and BAM -- there you have "unique enough" site-id
> identifier.  No need for any registrations etc.

This is a valid approach also. However, one might argue that it would be
nice to do it the right way and make them truly unique if it is not too
much of a hassle. 

> But I don't think we should be providing _globally
> routable_ addresses in the first place.  They answer
> some other problems than the one that's an argument in
> the site-local discussion.

Strongly agree.

Michel.

--------------------------------------------------------------------
IETF IPng Working Group Mailing List
IPng Home Page:                      http://playground.sun.com/ipng
FTP archive:                      ftp://playground.sun.com/pub/ipng
Direct all administrative requests to [email-masked]
--------------------------------------------------------------------

---

From: Kurt Erik Lindqvist <[email-masked]>
Date: Thu, 21 Nov 2002 20:46:36 +0100

> nice to do it the right way and make them truly unique if it is not too

Uhm, if they are truely unique, the only difference to global addresses 
is that they won't be routed - right? Now, what is the difference 
between that and using global unicast address space that you do not 
announce?

- kurtis -

---

From: Margaret Wasserman <[email-masked]>
Date: Sat, 23 Nov 2002 20:50:01 -0500

>
>Uhm, if they are truely unique, the only difference to global addresses is 
>that they won't be routed - right? Now, what is the difference between 
>that and using global unicast address space that you do not announce?

Virtually nothing, except that this address space would be
provider-independent, so you would not have to renumber, etc.
when you change ISPs.  Also, your ISP would not be obligated
to route it globally and would probably filter it.

I'm actually in favor of a globally-unique/provider-independent
address space that is routable, with borders of the address
space administratively determined and enforced via filtering
rules in routers/firewalls.

Margaret

---

From: Kurt Erik Lindqvist <[email-masked]>
Date: Wed, 27 Nov 2002 13:43:29 +0100

>> Uhm, if they are truely unique, the only difference to global 
>> addresses is that they won't be routed - right? Now, what is the 
>> difference between that and using global unicast address space that 
>> you do not announce?
>

But if there is no difference we are suggesting to create PI space 
right? And leave the scaling problem of the routing table to multi6 
group where it belongs?

What I am failing to understand is what we are looking for. The <insert 
letter>GUPI model will drive the development of NATs. Actually this 
would build NATs into the Internet architecture permanently. A number 
or people have pointed to the problems of this. That besides, if we now 
(I hope not) creates GUPI space, why do I then need site-locals as well?

Why do we need a separate allocation for GUPI? This could be all of the 
unicast addresses in IPv6.

Isn't this more or less 8+8?

- kurtis -

---

From: Keith Moore <[email-masked]>
Date: Wed, 27 Nov 2002 12:27:52 -0500

> The <insert letter>GUPI model will drive the development of NATs.

that's just nuts.  GUPIs don't encourage NATs any more than any other
aspect of IPv6.

I'm beginning to think that citing NATs as a reason for not doing 
something in IPv6 is like comparing someone to Hitler in a political
discussion - it's such an extreme statement that it can't be evaluated.

Keith

---

From: Margaret Wasserman <[email-masked]>
Date: Sat, 30 Nov 2002 18:35:31 -0500

>letter>GUPI model will drive the development of NATs.

Why do you think so?

In particular, why do you think that GUPI addresses would drive the
development of NATs any more than the current IPv6 site-local addresses?

Do you really think that it is realistic to just tell everyone to use
provider-assigned addresses throughout their network?

We've been getting feedback from network administrators that they need
a form of local addressing that allows their internal numbering, firewall
configuration, etc. to be independent of their ISP-provided addresses.

People want to use site-locals for this, but the ambiguity of site-locals
causes all sorts of problems for applications, routing protocols, transport
protocols, etc. especially when running on site border nodes (nodes that
are in more than one site at the same time).

It is my belief that if we ignore this problem, and simply limit site-
locals to disconnected networks (a la RFC 1918 addresses), then IPv6
NAT will arise to allow sites to separate internal addressing from
external addressing.

What we really need is a better way to solve this problem, one that doesn't
have the problems of site-local addresses.  And, that's why we're discussing
GUPI addresses.  Is there a better way to solve this problem that we
haven't considered?

Margaret