Subject: Why ULA-* will not harm the DFZ

From: Joe Abley <[email-masked]>
Date: Mon, 9 Jul 2007 22:24:43 -0400

The risk to the DFZ of leaking ULA-* {routes, packets, whatever}  
keeps coming up on this list. I thought I'd try to address just that  
problem in isolation, just to see whether I'm hearing things right.  
Please attack the following.

1. With PI address space there is an expectation of global utility  
(or, reachability across the DFZ, or however you want to describe  
"useful on the Internet"). I said expectation, not guarantee.

2. With ULA-* address space there would be no expectation of global  
utility. In fact, there would be an expectation that the addresses  
are for local use only (for some definition of "local").

3. There is doubt that any ULA-* address space would be kept properly  
local in all cases. In fact, there is an expectation that {routes,  
packets, something} would leak.

4. If some leaks are tolerated, then maybe, eventually, all leaks  
will be tolerated. Let's assume that will happen, just to see where  
it takes us.

5. If everybody has non-PA addresses (be they PI or ULA-*) and they  
are all leaked to the Internet, then the DFZ will suffer state  
explosion.

6. If operators can distinguish between should-be-local addresses  
(ULA-*) and allowed-to-be-global addresses (PI) in ASICs then  
operators can filter in order to head off the cataclysm looming in (5).

7. Since people were told up-front that their ULA-* addresses were no  
good for use on the Internet, step (6) shouldn't cause anybody to  
lock and load their lawyers.

(6) and (7) above ring true for ULA-* but not for PI-for-all. So, ULA- 
* would not harm the DFZ in the way that PI-for-all might harm the DFZ.

Joe

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From: "Azinger, Marla" <[email-masked]>
Date: Tue, 10 Jul 2007 18:00:18 -0400

I dont agree.

Marla Azinger

-----Original Message-----
From: [email-masked] [mailto:[email-masked]]
Sent: Tuesday, July 10, 2007 2:49 PM
To: [email-masked]
Subject: RE: [ppml] Why ULA-* will not harm the DFZ

> 2. Or release space FC00::/8 for another type of use (becuase 
> sitting on the shelf is wasteful)

This is a good example of ossified IPv4 thinking. IPv6 is different from
IPv4. It is not just IPv4 with more address bits. It is not wasteful to
leave IPv6 address ranges sitting on the shelf any more than it is
wasteful to assign a /48 prefix to a homeowner.

--Michael Dillon

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From: "Azinger, Marla" <[email-masked]>
Date: Wed, 11 Jul 2007 13:30:25 -0400

I think my main point on the first response I made to this string you started has taken a curve ball. I had no intentions of turning this into a conservation debate (though I do think it something to keep in mind).  The main point I made was to use them and complete the needed documentation needed or decide to use them for something else.  Which is inline with you saying we should make decisions in a finite timescale rather than deferring decisions forever out.

Marla

-----Original Message-----
From: Joe Abley [mailto:[email-masked]]
Sent: Wednesday, July 11, 2007 10:01 AM
To: Azinger, Marla
Cc: [email-masked]; [email-masked]
Subject: Re: [ppml] Why ULA-* will not harm the DFZ

On 11-Jul-2007, at 12:43, Azinger, Marla wrote:

> I am not surprised that conservation isn't the number one  
> priority.  I just don't think its wise to ignore conservation.  We  
> cant predict Ipv6 consumption and we don't even know what will  
> exist for technology in the future that will require IP Addresses.

I think with 128 bits there's a middle ground between ruthless  
conservation and "a /48 for every fridge"

But I guess my point was really that we shouldn't necessarily expect  
to guess right first time, every time, and it's nice to have some  
latitude to be able to make decisions in a finite timescale rather  
than deferring decisions for ever out of fear that they might be wrong.

Joe